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| author | peter <peter@FreeBSD.org> | 1996-09-18 05:35:50 +0000 |
|---|---|---|
| committer | peter <peter@FreeBSD.org> | 1996-09-18 05:35:50 +0000 |
| commit | d4691e641ba47cb86eef80f5c879e13f9d961724 (patch) | |
| tree | 5b7ea73fc49c8998d9dc87d3eeff5b96439e6856 /contrib/gcc/expmed.c | |
| download | FreeBSD-src-d4691e641ba47cb86eef80f5c879e13f9d961724.zip FreeBSD-src-d4691e641ba47cb86eef80f5c879e13f9d961724.tar.gz | |
Import of unmodified (but trimmed) gcc-2.7.2. The bigger parts of the
non-i386, non-unix, and generatable files have been trimmed, but can easily
be added in later if needed.
gcc-2.7.2.1 will follow shortly, it's a very small delta to this and it's
handy to have both available for reference for such little cost.
The freebsd-specific changes will then be committed, and once the dust has
settled, the bmakefiles will be committed to use this code.
Diffstat (limited to 'contrib/gcc/expmed.c')
| -rw-r--r-- | contrib/gcc/expmed.c | 4223 |
1 files changed, 4223 insertions, 0 deletions
diff --git a/contrib/gcc/expmed.c b/contrib/gcc/expmed.c new file mode 100644 index 0000000..8006e8b --- /dev/null +++ b/contrib/gcc/expmed.c @@ -0,0 +1,4223 @@ +/* Medium-level subroutines: convert bit-field store and extract + and shifts, multiplies and divides to rtl instructions. + Copyright (C) 1987, 88, 89, 92, 93, 94, 1995 Free Software Foundation, Inc. + +This file is part of GNU CC. + +GNU CC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU CC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU CC; see the file COPYING. If not, write to +the Free Software Foundation, 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + + +#include "config.h" +#include "rtl.h" +#include "tree.h" +#include "flags.h" +#include "insn-flags.h" +#include "insn-codes.h" +#include "insn-config.h" +#include "expr.h" +#include "real.h" +#include "recog.h" + +static void store_fixed_bit_field PROTO((rtx, int, int, int, rtx, int)); +static void store_split_bit_field PROTO((rtx, int, int, rtx, int)); +static rtx extract_fixed_bit_field PROTO((enum machine_mode, rtx, int, + int, int, rtx, int, int)); +static rtx mask_rtx PROTO((enum machine_mode, int, + int, int)); +static rtx lshift_value PROTO((enum machine_mode, rtx, + int, int)); +static rtx extract_split_bit_field PROTO((rtx, int, int, int, int)); + +#define CEIL(x,y) (((x) + (y) - 1) / (y)) + +/* Non-zero means divides or modulus operations are relatively cheap for + powers of two, so don't use branches; emit the operation instead. + Usually, this will mean that the MD file will emit non-branch + sequences. */ + +static int sdiv_pow2_cheap, smod_pow2_cheap; + +#ifndef SLOW_UNALIGNED_ACCESS +#define SLOW_UNALIGNED_ACCESS STRICT_ALIGNMENT +#endif + +/* For compilers that support multiple targets with different word sizes, + MAX_BITS_PER_WORD contains the biggest value of BITS_PER_WORD. An example + is the H8/300(H) compiler. */ + +#ifndef MAX_BITS_PER_WORD +#define MAX_BITS_PER_WORD BITS_PER_WORD +#endif + +/* Cost of various pieces of RTL. Note that some of these are indexed by shift count, + and some by mode. */ +static int add_cost, negate_cost, zero_cost; +static int shift_cost[MAX_BITS_PER_WORD]; +static int shiftadd_cost[MAX_BITS_PER_WORD]; +static int shiftsub_cost[MAX_BITS_PER_WORD]; +static int mul_cost[NUM_MACHINE_MODES]; +static int div_cost[NUM_MACHINE_MODES]; +static int mul_widen_cost[NUM_MACHINE_MODES]; +static int mul_highpart_cost[NUM_MACHINE_MODES]; + +void +init_expmed () +{ + char *free_point; + /* This is "some random pseudo register" for purposes of calling recog + to see what insns exist. */ + rtx reg = gen_rtx (REG, word_mode, 10000); + rtx shift_insn, shiftadd_insn, shiftsub_insn; + int dummy; + int m; + enum machine_mode mode, wider_mode; + + start_sequence (); + + /* Since we are on the permanent obstack, we must be sure we save this + spot AFTER we call start_sequence, since it will reuse the rtl it + makes. */ + + free_point = (char *) oballoc (0); + + zero_cost = rtx_cost (const0_rtx, 0); + add_cost = rtx_cost (gen_rtx (PLUS, word_mode, reg, reg), SET); + + shift_insn = emit_insn (gen_rtx (SET, VOIDmode, reg, + gen_rtx (ASHIFT, word_mode, reg, + const0_rtx))); + + shiftadd_insn = emit_insn (gen_rtx (SET, VOIDmode, reg, + gen_rtx (PLUS, word_mode, + gen_rtx (MULT, word_mode, + reg, const0_rtx), + reg))); + + shiftsub_insn = emit_insn (gen_rtx (SET, VOIDmode, reg, + gen_rtx (MINUS, word_mode, + gen_rtx (MULT, word_mode, + reg, const0_rtx), + reg))); + + init_recog (); + + shift_cost[0] = 0; + shiftadd_cost[0] = shiftsub_cost[0] = add_cost; + + for (m = 1; m < BITS_PER_WORD; m++) + { + shift_cost[m] = shiftadd_cost[m] = shiftsub_cost[m] = 32000; + + XEXP (SET_SRC (PATTERN (shift_insn)), 1) = GEN_INT (m); + if (recog (PATTERN (shift_insn), shift_insn, &dummy) >= 0) + shift_cost[m] = rtx_cost (SET_SRC (PATTERN (shift_insn)), SET); + + XEXP (XEXP (SET_SRC (PATTERN (shiftadd_insn)), 0), 1) + = GEN_INT ((HOST_WIDE_INT) 1 << m); + if (recog (PATTERN (shiftadd_insn), shiftadd_insn, &dummy) >= 0) + shiftadd_cost[m] = rtx_cost (SET_SRC (PATTERN (shiftadd_insn)), SET); + + XEXP (XEXP (SET_SRC (PATTERN (shiftsub_insn)), 0), 1) + = GEN_INT ((HOST_WIDE_INT) 1 << m); + if (recog (PATTERN (shiftsub_insn), shiftsub_insn, &dummy) >= 0) + shiftsub_cost[m] = rtx_cost (SET_SRC (PATTERN (shiftsub_insn)), SET); + } + + negate_cost = rtx_cost (gen_rtx (NEG, word_mode, reg), SET); + + sdiv_pow2_cheap + = (rtx_cost (gen_rtx (DIV, word_mode, reg, GEN_INT (32)), SET) + <= 2 * add_cost); + smod_pow2_cheap + = (rtx_cost (gen_rtx (MOD, word_mode, reg, GEN_INT (32)), SET) + <= 2 * add_cost); + + for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); + mode != VOIDmode; + mode = GET_MODE_WIDER_MODE (mode)) + { + reg = gen_rtx (REG, mode, 10000); + div_cost[(int) mode] = rtx_cost (gen_rtx (UDIV, mode, reg, reg), SET); + mul_cost[(int) mode] = rtx_cost (gen_rtx (MULT, mode, reg, reg), SET); + wider_mode = GET_MODE_WIDER_MODE (mode); + if (wider_mode != VOIDmode) + { + mul_widen_cost[(int) wider_mode] + = rtx_cost (gen_rtx (MULT, wider_mode, + gen_rtx (ZERO_EXTEND, wider_mode, reg), + gen_rtx (ZERO_EXTEND, wider_mode, reg)), + SET); + mul_highpart_cost[(int) mode] + = rtx_cost (gen_rtx (TRUNCATE, mode, + gen_rtx (LSHIFTRT, wider_mode, + gen_rtx (MULT, wider_mode, + gen_rtx (ZERO_EXTEND, wider_mode, reg), + gen_rtx (ZERO_EXTEND, wider_mode, reg)), + GEN_INT (GET_MODE_BITSIZE (mode)))), + SET); + } + } + + /* Free the objects we just allocated. */ + end_sequence (); + obfree (free_point); +} + +/* Return an rtx representing minus the value of X. + MODE is the intended mode of the result, + useful if X is a CONST_INT. */ + +rtx +negate_rtx (mode, x) + enum machine_mode mode; + rtx x; +{ + if (GET_CODE (x) == CONST_INT) + { + HOST_WIDE_INT val = - INTVAL (x); + if (GET_MODE_BITSIZE (mode) < HOST_BITS_PER_WIDE_INT) + { + /* Sign extend the value from the bits that are significant. */ + if (val & ((HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1))) + val |= (HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (mode); + else + val &= ((HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (mode)) - 1; + } + return GEN_INT (val); + } + else + return expand_unop (GET_MODE (x), neg_optab, x, NULL_RTX, 0); +} + +/* Generate code to store value from rtx VALUE + into a bit-field within structure STR_RTX + containing BITSIZE bits starting at bit BITNUM. + FIELDMODE is the machine-mode of the FIELD_DECL node for this field. + ALIGN is the alignment that STR_RTX is known to have, measured in bytes. + TOTAL_SIZE is the size of the structure in bytes, or -1 if varying. */ + +/* ??? Note that there are two different ideas here for how + to determine the size to count bits within, for a register. + One is BITS_PER_WORD, and the other is the size of operand 3 + of the insv pattern. (The latter assumes that an n-bit machine + will be able to insert bit fields up to n bits wide.) + It isn't certain that either of these is right. + extract_bit_field has the same quandary. */ + +rtx +store_bit_field (str_rtx, bitsize, bitnum, fieldmode, value, align, total_size) + rtx str_rtx; + register int bitsize; + int bitnum; + enum machine_mode fieldmode; + rtx value; + int align; + int total_size; +{ + int unit = (GET_CODE (str_rtx) == MEM) ? BITS_PER_UNIT : BITS_PER_WORD; + register int offset = bitnum / unit; + register int bitpos = bitnum % unit; + register rtx op0 = str_rtx; + + if (GET_CODE (str_rtx) == MEM && ! MEM_IN_STRUCT_P (str_rtx)) + abort (); + + /* Discount the part of the structure before the desired byte. + We need to know how many bytes are safe to reference after it. */ + if (total_size >= 0) + total_size -= (bitpos / BIGGEST_ALIGNMENT + * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); + + while (GET_CODE (op0) == SUBREG) + { + /* The following line once was done only if WORDS_BIG_ENDIAN, + but I think that is a mistake. WORDS_BIG_ENDIAN is + meaningful at a much higher level; when structures are copied + between memory and regs, the higher-numbered regs + always get higher addresses. */ + offset += SUBREG_WORD (op0); + /* We used to adjust BITPOS here, but now we do the whole adjustment + right after the loop. */ + op0 = SUBREG_REG (op0); + } + + /* If OP0 is a register, BITPOS must count within a word. + But as we have it, it counts within whatever size OP0 now has. + On a bigendian machine, these are not the same, so convert. */ + if (BYTES_BIG_ENDIAN + && GET_CODE (op0) != MEM + && unit > GET_MODE_BITSIZE (GET_MODE (op0))) + bitpos += unit - GET_MODE_BITSIZE (GET_MODE (op0)); + + value = protect_from_queue (value, 0); + + if (flag_force_mem) + value = force_not_mem (value); + + /* Note that the adjustment of BITPOS above has no effect on whether + BITPOS is 0 in a REG bigger than a word. */ + if (GET_MODE_SIZE (fieldmode) >= UNITS_PER_WORD + && (GET_CODE (op0) != MEM + || ! SLOW_UNALIGNED_ACCESS + || (offset * BITS_PER_UNIT % bitsize == 0 + && align % GET_MODE_SIZE (fieldmode) == 0)) + && bitpos == 0 && bitsize == GET_MODE_BITSIZE (fieldmode)) + { + /* Storing in a full-word or multi-word field in a register + can be done with just SUBREG. */ + if (GET_MODE (op0) != fieldmode) + { + if (GET_CODE (op0) == REG) + op0 = gen_rtx (SUBREG, fieldmode, op0, offset); + else + op0 = change_address (op0, fieldmode, + plus_constant (XEXP (op0, 0), offset)); + } + emit_move_insn (op0, value); + return value; + } + + /* Storing an lsb-aligned field in a register + can be done with a movestrict instruction. */ + + if (GET_CODE (op0) != MEM + && (BYTES_BIG_ENDIAN ? bitpos + bitsize == unit : bitpos == 0) + && bitsize == GET_MODE_BITSIZE (fieldmode) + && (GET_MODE (op0) == fieldmode + || (movstrict_optab->handlers[(int) fieldmode].insn_code + != CODE_FOR_nothing))) + { + /* Get appropriate low part of the value being stored. */ + if (GET_CODE (value) == CONST_INT || GET_CODE (value) == REG) + value = gen_lowpart (fieldmode, value); + else if (!(GET_CODE (value) == SYMBOL_REF + || GET_CODE (value) == LABEL_REF + || GET_CODE (value) == CONST)) + value = convert_to_mode (fieldmode, value, 0); + + if (GET_MODE (op0) == fieldmode) + emit_move_insn (op0, value); + else + { + int icode = movstrict_optab->handlers[(int) fieldmode].insn_code; + if(! (*insn_operand_predicate[icode][1]) (value, fieldmode)) + value = copy_to_mode_reg (fieldmode, value); + emit_insn (GEN_FCN (icode) + (gen_rtx (SUBREG, fieldmode, op0, offset), value)); + } + return value; + } + + /* Handle fields bigger than a word. */ + + if (bitsize > BITS_PER_WORD) + { + /* Here we transfer the words of the field + in the order least significant first. + This is because the most significant word is the one which may + be less than full. + However, only do that if the value is not BLKmode. */ + + int backwards = WORDS_BIG_ENDIAN && fieldmode != BLKmode; + + int nwords = (bitsize + (BITS_PER_WORD - 1)) / BITS_PER_WORD; + int i; + + /* This is the mode we must force value to, so that there will be enough + subwords to extract. Note that fieldmode will often (always?) be + VOIDmode, because that is what store_field uses to indicate that this + is a bit field, but passing VOIDmode to operand_subword_force will + result in an abort. */ + fieldmode = mode_for_size (nwords * BITS_PER_WORD, MODE_INT, 0); + + for (i = 0; i < nwords; i++) + { + /* If I is 0, use the low-order word in both field and target; + if I is 1, use the next to lowest word; and so on. */ + int wordnum = (backwards ? nwords - i - 1 : i); + int bit_offset = (backwards + ? MAX (bitsize - (i + 1) * BITS_PER_WORD, 0) + : i * BITS_PER_WORD); + store_bit_field (op0, MIN (BITS_PER_WORD, + bitsize - i * BITS_PER_WORD), + bitnum + bit_offset, word_mode, + operand_subword_force (value, wordnum, + (GET_MODE (value) == VOIDmode + ? fieldmode + : GET_MODE (value))), + align, total_size); + } + return value; + } + + /* From here on we can assume that the field to be stored in is + a full-word (whatever type that is), since it is shorter than a word. */ + + /* OFFSET is the number of words or bytes (UNIT says which) + from STR_RTX to the first word or byte containing part of the field. */ + + if (GET_CODE (op0) == REG) + { + if (offset != 0 + || GET_MODE_SIZE (GET_MODE (op0)) > UNITS_PER_WORD) + op0 = gen_rtx (SUBREG, TYPE_MODE (type_for_size (BITS_PER_WORD, 0)), + op0, offset); + offset = 0; + } + else + { + op0 = protect_from_queue (op0, 1); + } + + /* If VALUE is a floating-point mode, access it as an integer of the + corresponding size. This can occur on a machine with 64 bit registers + that uses SFmode for float. This can also occur for unaligned float + structure fields. */ + if (GET_MODE_CLASS (GET_MODE (value)) == MODE_FLOAT) + { + if (GET_CODE (value) != REG) + value = copy_to_reg (value); + value = gen_rtx (SUBREG, word_mode, value, 0); + } + + /* Now OFFSET is nonzero only if OP0 is memory + and is therefore always measured in bytes. */ + +#ifdef HAVE_insv + if (HAVE_insv + && !(bitsize == 1 && GET_CODE (value) == CONST_INT) + /* Ensure insv's size is wide enough for this field. */ + && (GET_MODE_BITSIZE (insn_operand_mode[(int) CODE_FOR_insv][3]) + >= bitsize) + && ! ((GET_CODE (op0) == REG || GET_CODE (op0) == SUBREG) + && (bitsize + bitpos + > GET_MODE_BITSIZE (insn_operand_mode[(int) CODE_FOR_insv][3])))) + { + int xbitpos = bitpos; + rtx value1; + rtx xop0 = op0; + rtx last = get_last_insn (); + rtx pat; + enum machine_mode maxmode + = insn_operand_mode[(int) CODE_FOR_insv][3]; + + int save_volatile_ok = volatile_ok; + volatile_ok = 1; + + /* If this machine's insv can only insert into a register, or if we + are to force MEMs into a register, copy OP0 into a register and + save it back later. */ + if (GET_CODE (op0) == MEM + && (flag_force_mem + || ! ((*insn_operand_predicate[(int) CODE_FOR_insv][0]) + (op0, VOIDmode)))) + { + rtx tempreg; + enum machine_mode bestmode; + + /* Get the mode to use for inserting into this field. If OP0 is + BLKmode, get the smallest mode consistent with the alignment. If + OP0 is a non-BLKmode object that is no wider than MAXMODE, use its + mode. Otherwise, use the smallest mode containing the field. */ + + if (GET_MODE (op0) == BLKmode + || GET_MODE_SIZE (GET_MODE (op0)) > GET_MODE_SIZE (maxmode)) + bestmode + = get_best_mode (bitsize, bitnum, align * BITS_PER_UNIT, maxmode, + MEM_VOLATILE_P (op0)); + else + bestmode = GET_MODE (op0); + + if (bestmode == VOIDmode + || (SLOW_UNALIGNED_ACCESS && GET_MODE_SIZE (bestmode) > align)) + goto insv_loses; + + /* Adjust address to point to the containing unit of that mode. */ + unit = GET_MODE_BITSIZE (bestmode); + /* Compute offset as multiple of this unit, counting in bytes. */ + offset = (bitnum / unit) * GET_MODE_SIZE (bestmode); + bitpos = bitnum % unit; + op0 = change_address (op0, bestmode, + plus_constant (XEXP (op0, 0), offset)); + + /* Fetch that unit, store the bitfield in it, then store the unit. */ + tempreg = copy_to_reg (op0); + store_bit_field (tempreg, bitsize, bitpos, fieldmode, value, + align, total_size); + emit_move_insn (op0, tempreg); + return value; + } + volatile_ok = save_volatile_ok; + + /* Add OFFSET into OP0's address. */ + if (GET_CODE (xop0) == MEM) + xop0 = change_address (xop0, byte_mode, + plus_constant (XEXP (xop0, 0), offset)); + + /* If xop0 is a register, we need it in MAXMODE + to make it acceptable to the format of insv. */ + if (GET_CODE (xop0) == SUBREG) + /* We can't just change the mode, because this might clobber op0, + and we will need the original value of op0 if insv fails. */ + xop0 = gen_rtx (SUBREG, maxmode, SUBREG_REG (xop0), SUBREG_WORD (xop0)); + if (GET_CODE (xop0) == REG && GET_MODE (xop0) != maxmode) + xop0 = gen_rtx (SUBREG, maxmode, xop0, 0); + + /* On big-endian machines, we count bits from the most significant. + If the bit field insn does not, we must invert. */ + + if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN) + xbitpos = unit - bitsize - xbitpos; + + /* We have been counting XBITPOS within UNIT. + Count instead within the size of the register. */ + if (BITS_BIG_ENDIAN && GET_CODE (xop0) != MEM) + xbitpos += GET_MODE_BITSIZE (maxmode) - unit; + + unit = GET_MODE_BITSIZE (maxmode); + + /* Convert VALUE to maxmode (which insv insn wants) in VALUE1. */ + value1 = value; + if (GET_MODE (value) != maxmode) + { + if (GET_MODE_BITSIZE (GET_MODE (value)) >= bitsize) + { + /* Optimization: Don't bother really extending VALUE + if it has all the bits we will actually use. However, + if we must narrow it, be sure we do it correctly. */ + + if (GET_MODE_SIZE (GET_MODE (value)) < GET_MODE_SIZE (maxmode)) + { + /* Avoid making subreg of a subreg, or of a mem. */ + if (GET_CODE (value1) != REG) + value1 = copy_to_reg (value1); + value1 = gen_rtx (SUBREG, maxmode, value1, 0); + } + else + value1 = gen_lowpart (maxmode, value1); + } + else if (!CONSTANT_P (value)) + /* Parse phase is supposed to make VALUE's data type + match that of the component reference, which is a type + at least as wide as the field; so VALUE should have + a mode that corresponds to that type. */ + abort (); + } + + /* If this machine's insv insists on a register, + get VALUE1 into a register. */ + if (! ((*insn_operand_predicate[(int) CODE_FOR_insv][3]) + (value1, maxmode))) + value1 = force_reg (maxmode, value1); + + pat = gen_insv (xop0, GEN_INT (bitsize), GEN_INT (xbitpos), value1); + if (pat) + emit_insn (pat); + else + { + delete_insns_since (last); + store_fixed_bit_field (op0, offset, bitsize, bitpos, value, align); + } + } + else + insv_loses: +#endif + /* Insv is not available; store using shifts and boolean ops. */ + store_fixed_bit_field (op0, offset, bitsize, bitpos, value, align); + return value; +} + +/* Use shifts and boolean operations to store VALUE + into a bit field of width BITSIZE + in a memory location specified by OP0 except offset by OFFSET bytes. + (OFFSET must be 0 if OP0 is a register.) + The field starts at position BITPOS within the byte. + (If OP0 is a register, it may be a full word or a narrower mode, + but BITPOS still counts within a full word, + which is significant on bigendian machines.) + STRUCT_ALIGN is the alignment the structure is known to have (in bytes). + + Note that protect_from_queue has already been done on OP0 and VALUE. */ + +static void +store_fixed_bit_field (op0, offset, bitsize, bitpos, value, struct_align) + register rtx op0; + register int offset, bitsize, bitpos; + register rtx value; + int struct_align; +{ + register enum machine_mode mode; + int total_bits = BITS_PER_WORD; + rtx subtarget, temp; + int all_zero = 0; + int all_one = 0; + + /* There is a case not handled here: + a structure with a known alignment of just a halfword + and a field split across two aligned halfwords within the structure. + Or likewise a structure with a known alignment of just a byte + and a field split across two bytes. + Such cases are not supposed to be able to occur. */ + + if (GET_CODE (op0) == REG || GET_CODE (op0) == SUBREG) + { + if (offset != 0) + abort (); + /* Special treatment for a bit field split across two registers. */ + if (bitsize + bitpos > BITS_PER_WORD) + { + store_split_bit_field (op0, bitsize, bitpos, + value, BITS_PER_WORD); + return; + } + } + else + { + /* Get the proper mode to use for this field. We want a mode that + includes the entire field. If such a mode would be larger than + a word, we won't be doing the extraction the normal way. */ + + mode = get_best_mode (bitsize, bitpos + offset * BITS_PER_UNIT, + struct_align * BITS_PER_UNIT, word_mode, + GET_CODE (op0) == MEM && MEM_VOLATILE_P (op0)); + + if (mode == VOIDmode) + { + /* The only way this should occur is if the field spans word + boundaries. */ + store_split_bit_field (op0, + bitsize, bitpos + offset * BITS_PER_UNIT, + value, struct_align); + return; + } + + total_bits = GET_MODE_BITSIZE (mode); + + /* Make sure bitpos is valid for the chosen mode. Adjust BITPOS to + be be in the range 0 to total_bits-1, and put any excess bytes in + OFFSET. */ + if (bitpos >= total_bits) + { + offset += (bitpos / total_bits) * (total_bits / BITS_PER_UNIT); + bitpos -= ((bitpos / total_bits) * (total_bits / BITS_PER_UNIT) + * BITS_PER_UNIT); + } + + /* Get ref to an aligned byte, halfword, or word containing the field. + Adjust BITPOS to be position within a word, + and OFFSET to be the offset of that word. + Then alter OP0 to refer to that word. */ + bitpos += (offset % (total_bits / BITS_PER_UNIT)) * BITS_PER_UNIT; + offset -= (offset % (total_bits / BITS_PER_UNIT)); + op0 = change_address (op0, mode, + plus_constant (XEXP (op0, 0), offset)); + } + + mode = GET_MODE (op0); + + /* Now MODE is either some integral mode for a MEM as OP0, + or is a full-word for a REG as OP0. TOTAL_BITS corresponds. + The bit field is contained entirely within OP0. + BITPOS is the starting bit number within OP0. + (OP0's mode may actually be narrower than MODE.) */ + + if (BYTES_BIG_ENDIAN) + /* BITPOS is the distance between our msb + and that of the containing datum. + Convert it to the distance from the lsb. */ + bitpos = total_bits - bitsize - bitpos; + + /* Now BITPOS is always the distance between our lsb + and that of OP0. */ + + /* Shift VALUE left by BITPOS bits. If VALUE is not constant, + we must first convert its mode to MODE. */ + + if (GET_CODE (value) == CONST_INT) + { + register HOST_WIDE_INT v = INTVAL (value); + + if (bitsize < HOST_BITS_PER_WIDE_INT) + v &= ((HOST_WIDE_INT) 1 << bitsize) - 1; + + if (v == 0) + all_zero = 1; + else if ((bitsize < HOST_BITS_PER_WIDE_INT + && v == ((HOST_WIDE_INT) 1 << bitsize) - 1) + || (bitsize == HOST_BITS_PER_WIDE_INT && v == -1)) + all_one = 1; + + value = lshift_value (mode, value, bitpos, bitsize); + } + else + { + int must_and = (GET_MODE_BITSIZE (GET_MODE (value)) != bitsize + && bitpos + bitsize != GET_MODE_BITSIZE (mode)); + + if (GET_MODE (value) != mode) + { + if ((GET_CODE (value) == REG || GET_CODE (value) == SUBREG) + && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (value))) + value = gen_lowpart (mode, value); + else + value = convert_to_mode (mode, value, 1); + } + + if (must_and) + value = expand_binop (mode, and_optab, value, + mask_rtx (mode, 0, bitsize, 0), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + if (bitpos > 0) + value = expand_shift (LSHIFT_EXPR, mode, value, + build_int_2 (bitpos, 0), NULL_RTX, 1); + } + + /* Now clear the chosen bits in OP0, + except that if VALUE is -1 we need not bother. */ + + subtarget = (GET_CODE (op0) == REG || ! flag_force_mem) ? op0 : 0; + + if (! all_one) + { + temp = expand_binop (mode, and_optab, op0, + mask_rtx (mode, bitpos, bitsize, 1), + subtarget, 1, OPTAB_LIB_WIDEN); + subtarget = temp; + } + else + temp = op0; + + /* Now logical-or VALUE into OP0, unless it is zero. */ + + if (! all_zero) + temp = expand_binop (mode, ior_optab, temp, value, + subtarget, 1, OPTAB_LIB_WIDEN); + if (op0 != temp) + emit_move_insn (op0, temp); +} + +/* Store a bit field that is split across multiple accessible memory objects. + + OP0 is the REG, SUBREG or MEM rtx for the first of the objects. + BITSIZE is the field width; BITPOS the position of its first bit + (within the word). + VALUE is the value to store. + ALIGN is the known alignment of OP0, measured in bytes. + This is also the size of the memory objects to be used. + + This does not yet handle fields wider than BITS_PER_WORD. */ + +static void +store_split_bit_field (op0, bitsize, bitpos, value, align) + rtx op0; + int bitsize, bitpos; + rtx value; + int align; +{ + int unit; + int bitsdone = 0; + + /* Make sure UNIT isn't larger than BITS_PER_WORD, we can only handle that + much at a time. */ + if (GET_CODE (op0) == REG || GET_CODE (op0) == SUBREG) + unit = BITS_PER_WORD; + else + unit = MIN (align * BITS_PER_UNIT, BITS_PER_WORD); + + /* If VALUE is a constant other than a CONST_INT, get it into a register in + WORD_MODE. If we can do this using gen_lowpart_common, do so. Note + that VALUE might be a floating-point constant. */ + if (CONSTANT_P (value) && GET_CODE (value) != CONST_INT) + { + rtx word = gen_lowpart_common (word_mode, value); + + if (word && (value != word)) + value = word; + else + value = gen_lowpart_common (word_mode, + force_reg (GET_MODE (value) != VOIDmode + ? GET_MODE (value) + : word_mode, value)); + } + + while (bitsdone < bitsize) + { + int thissize; + rtx part, word; + int thispos; + int offset; + + offset = (bitpos + bitsdone) / unit; + thispos = (bitpos + bitsdone) % unit; + + /* THISSIZE must not overrun a word boundary. Otherwise, + store_fixed_bit_field will call us again, and we will mutually + recurse forever. */ + thissize = MIN (bitsize - bitsdone, BITS_PER_WORD); + thissize = MIN (thissize, unit - thispos); + + if (BYTES_BIG_ENDIAN) + { + int total_bits; + + /* We must do an endian conversion exactly the same way as it is + done in extract_bit_field, so that the two calls to + extract_fixed_bit_field will have comparable arguments. */ + if (GET_CODE (value) != MEM) + total_bits = BITS_PER_WORD; + else + total_bits = GET_MODE_BITSIZE (GET_MODE (value)); + + /* Fetch successively less significant portions. */ + if (GET_CODE (value) == CONST_INT) + part = GEN_INT (((unsigned HOST_WIDE_INT) (INTVAL (value)) + >> (bitsize - bitsdone - thissize)) + & (((HOST_WIDE_INT) 1 << thissize) - 1)); + else + /* The args are chosen so that the last part includes the + lsb. Give extract_bit_field the value it needs (with + endianness compensation) to fetch the piece we want. */ + part = extract_fixed_bit_field (word_mode, value, 0, thissize, + total_bits - bitsize + bitsdone, + NULL_RTX, 1, align); + } + else + { + /* Fetch successively more significant portions. */ + if (GET_CODE (value) == CONST_INT) + part = GEN_INT (((unsigned HOST_WIDE_INT) (INTVAL (value)) + >> bitsdone) + & (((HOST_WIDE_INT) 1 << thissize) - 1)); + else + part = extract_fixed_bit_field (word_mode, value, 0, thissize, + bitsdone, NULL_RTX, 1, align); + } + + /* If OP0 is a register, then handle OFFSET here. + + When handling multiword bitfields, extract_bit_field may pass + down a word_mode SUBREG of a larger REG for a bitfield that actually + crosses a word boundary. Thus, for a SUBREG, we must find + the current word starting from the base register. */ + if (GET_CODE (op0) == SUBREG) + { + word = operand_subword_force (SUBREG_REG (op0), + SUBREG_WORD (op0) + offset, + GET_MODE (SUBREG_REG (op0))); + offset = 0; + } + else if (GET_CODE (op0) == REG) + { + word = operand_subword_force (op0, offset, GET_MODE (op0)); + offset = 0; + } + else + word = op0; + + /* OFFSET is in UNITs, and UNIT is in bits. + store_fixed_bit_field wants offset in bytes. */ + store_fixed_bit_field (word, offset * unit / BITS_PER_UNIT, + thissize, thispos, part, align); + bitsdone += thissize; + } +} + +/* Generate code to extract a byte-field from STR_RTX + containing BITSIZE bits, starting at BITNUM, + and put it in TARGET if possible (if TARGET is nonzero). + Regardless of TARGET, we return the rtx for where the value is placed. + It may be a QUEUED. + + STR_RTX is the structure containing the byte (a REG or MEM). + UNSIGNEDP is nonzero if this is an unsigned bit field. + MODE is the natural mode of the field value once extracted. + TMODE is the mode the caller would like the value to have; + but the value may be returned with type MODE instead. + + ALIGN is the alignment that STR_RTX is known to have, measured in bytes. + TOTAL_SIZE is the size in bytes of the containing structure, + or -1 if varying. + + If a TARGET is specified and we can store in it at no extra cost, + we do so, and return TARGET. + Otherwise, we return a REG of mode TMODE or MODE, with TMODE preferred + if they are equally easy. */ + +rtx +extract_bit_field (str_rtx, bitsize, bitnum, unsignedp, + target, mode, tmode, align, total_size) + rtx str_rtx; + register int bitsize; + int bitnum; + int unsignedp; + rtx target; + enum machine_mode mode, tmode; + int align; + int total_size; +{ + int unit = (GET_CODE (str_rtx) == MEM) ? BITS_PER_UNIT : BITS_PER_WORD; + register int offset = bitnum / unit; + register int bitpos = bitnum % unit; + register rtx op0 = str_rtx; + rtx spec_target = target; + rtx spec_target_subreg = 0; + + if (GET_CODE (str_rtx) == MEM && ! MEM_IN_STRUCT_P (str_rtx)) + abort (); + + /* Discount the part of the structure before the desired byte. + We need to know how many bytes are safe to reference after it. */ + if (total_size >= 0) + total_size -= (bitpos / BIGGEST_ALIGNMENT + * (BIGGEST_ALIGNMENT / BITS_PER_UNIT)); + + if (tmode == VOIDmode) + tmode = mode; + while (GET_CODE (op0) == SUBREG) + { + int outer_size = GET_MODE_BITSIZE (GET_MODE (op0)); + int inner_size = GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (op0))); + + offset += SUBREG_WORD (op0); + + if (BYTES_BIG_ENDIAN && (outer_size < inner_size)) + { + bitpos += inner_size - outer_size; + if (bitpos > unit) + { + offset += (bitpos / unit); + bitpos %= unit; + } + } + + op0 = SUBREG_REG (op0); + } + + /* ??? We currently assume TARGET is at least as big as BITSIZE. + If that's wrong, the solution is to test for it and set TARGET to 0 + if needed. */ + + /* If OP0 is a register, BITPOS must count within a word. + But as we have it, it counts within whatever size OP0 now has. + On a bigendian machine, these are not the same, so convert. */ + if (BYTES_BIG_ENDIAN && + GET_CODE (op0) != MEM + && unit > GET_MODE_BITSIZE (GET_MODE (op0))) + bitpos += unit - GET_MODE_BITSIZE (GET_MODE (op0)); + + /* Extracting a full-word or multi-word value + from a structure in a register or aligned memory. + This can be done with just SUBREG. + So too extracting a subword value in + the least significant part of the register. */ + + if ((GET_CODE (op0) == REG + || (GET_CODE (op0) == MEM + && (! SLOW_UNALIGNED_ACCESS + || (offset * BITS_PER_UNIT % bitsize == 0 + && align * BITS_PER_UNIT % bitsize == 0)))) + && ((bitsize >= BITS_PER_WORD && bitsize == GET_MODE_BITSIZE (mode) + && bitpos % BITS_PER_WORD == 0) + || (mode_for_size (bitsize, GET_MODE_CLASS (tmode), 0) != BLKmode + && (BYTES_BIG_ENDIAN + ? bitpos + bitsize == BITS_PER_WORD + : bitpos == 0)))) + { + enum machine_mode mode1 + = mode_for_size (bitsize, GET_MODE_CLASS (tmode), 0); + + if (mode1 != GET_MODE (op0)) + { + if (GET_CODE (op0) == REG) + op0 = gen_rtx (SUBREG, mode1, op0, offset); + else + op0 = change_address (op0, mode1, + plus_constant (XEXP (op0, 0), offset)); + } + if (mode1 != mode) + return convert_to_mode (tmode, op0, unsignedp); + return op0; + } + + /* Handle fields bigger than a word. */ + + if (bitsize > BITS_PER_WORD) + { + /* Here we transfer the words of the field + in the order least significant first. + This is because the most significant word is the one which may + be less than full. */ + + int nwords = (bitsize + (BITS_PER_WORD - 1)) / BITS_PER_WORD; + int i; + + if (target == 0 || GET_CODE (target) != REG) + target = gen_reg_rtx (mode); + + for (i = 0; i < nwords; i++) + { + /* If I is 0, use the low-order word in both field and target; + if I is 1, use the next to lowest word; and so on. */ + /* Word number in TARGET to use. */ + int wordnum = (WORDS_BIG_ENDIAN + ? GET_MODE_SIZE (GET_MODE (target)) / UNITS_PER_WORD - i - 1 + : i); + /* Offset from start of field in OP0. */ + int bit_offset = (WORDS_BIG_ENDIAN + ? MAX (0, bitsize - (i + 1) * BITS_PER_WORD) + : i * BITS_PER_WORD); + rtx target_part = operand_subword (target, wordnum, 1, VOIDmode); + rtx result_part + = extract_bit_field (op0, MIN (BITS_PER_WORD, + bitsize - i * BITS_PER_WORD), + bitnum + bit_offset, + 1, target_part, mode, word_mode, + align, total_size); + + if (target_part == 0) + abort (); + + if (result_part != target_part) + emit_move_insn (target_part, result_part); + } + + if (unsignedp) + { + /* Unless we've filled TARGET, the upper regs in a multi-reg value + need to be zero'd out. */ + if (GET_MODE_SIZE (GET_MODE (target)) > nwords * UNITS_PER_WORD) + { + int i,total_words; + + total_words = GET_MODE_SIZE (GET_MODE (target)) / UNITS_PER_WORD; + for (i = nwords; i < total_words; i++) + { + int wordnum = WORDS_BIG_ENDIAN ? total_words - i - 1 : i; + rtx target_part = operand_subword (target, wordnum, 1, VOIDmode); + emit_move_insn (target_part, const0_rtx); + } + } + return target; + } + + /* Signed bit field: sign-extend with two arithmetic shifts. */ + target = expand_shift (LSHIFT_EXPR, mode, target, + build_int_2 (GET_MODE_BITSIZE (mode) - bitsize, 0), + NULL_RTX, 0); + return expand_shift (RSHIFT_EXPR, mode, target, + build_int_2 (GET_MODE_BITSIZE (mode) - bitsize, 0), + NULL_RTX, 0); + } + + /* From here on we know the desired field is smaller than a word + so we can assume it is an integer. So we can safely extract it as one + size of integer, if necessary, and then truncate or extend + to the size that is wanted. */ + + /* OFFSET is the number of words or bytes (UNIT says which) + from STR_RTX to the first word or byte containing part of the field. */ + + if (GET_CODE (op0) == REG) + { + if (offset != 0 + || GET_MODE_SIZE (GET_MODE (op0)) > UNITS_PER_WORD) + op0 = gen_rtx (SUBREG, TYPE_MODE (type_for_size (BITS_PER_WORD, 0)), + op0, offset); + offset = 0; + } + else + { + op0 = protect_from_queue (str_rtx, 1); + } + + /* Now OFFSET is nonzero only for memory operands. */ + + if (unsignedp) + { +#ifdef HAVE_extzv + if (HAVE_extzv + && (GET_MODE_BITSIZE (insn_operand_mode[(int) CODE_FOR_extzv][0]) + >= bitsize) + && ! ((GET_CODE (op0) == REG || GET_CODE (op0) == SUBREG) + && (bitsize + bitpos + > GET_MODE_BITSIZE (insn_operand_mode[(int) CODE_FOR_extzv][0])))) + { + int xbitpos = bitpos, xoffset = offset; + rtx bitsize_rtx, bitpos_rtx; + rtx last = get_last_insn(); + rtx xop0 = op0; + rtx xtarget = target; + rtx xspec_target = spec_target; + rtx xspec_target_subreg = spec_target_subreg; + rtx pat; + enum machine_mode maxmode + = insn_operand_mode[(int) CODE_FOR_extzv][0]; + + if (GET_CODE (xop0) == MEM) + { + int save_volatile_ok = volatile_ok; + volatile_ok = 1; + + /* Is the memory operand acceptable? */ + if (flag_force_mem + || ! ((*insn_operand_predicate[(int) CODE_FOR_extzv][1]) + (xop0, GET_MODE (xop0)))) + { + /* No, load into a reg and extract from there. */ + enum machine_mode bestmode; + + /* Get the mode to use for inserting into this field. If + OP0 is BLKmode, get the smallest mode consistent with the + alignment. If OP0 is a non-BLKmode object that is no + wider than MAXMODE, use its mode. Otherwise, use the + smallest mode containing the field. */ + + if (GET_MODE (xop0) == BLKmode + || (GET_MODE_SIZE (GET_MODE (op0)) + > GET_MODE_SIZE (maxmode))) + bestmode = get_best_mode (bitsize, bitnum, + align * BITS_PER_UNIT, maxmode, + MEM_VOLATILE_P (xop0)); + else + bestmode = GET_MODE (xop0); + + if (bestmode == VOIDmode + || (SLOW_UNALIGNED_ACCESS && GET_MODE_SIZE (bestmode) > align)) + goto extzv_loses; + + /* Compute offset as multiple of this unit, + counting in bytes. */ + unit = GET_MODE_BITSIZE (bestmode); + xoffset = (bitnum / unit) * GET_MODE_SIZE (bestmode); + xbitpos = bitnum % unit; + xop0 = change_address (xop0, bestmode, + plus_constant (XEXP (xop0, 0), + xoffset)); + /* Fetch it to a register in that size. */ + xop0 = force_reg (bestmode, xop0); + + /* XBITPOS counts within UNIT, which is what is expected. */ + } + else + /* Get ref to first byte containing part of the field. */ + xop0 = change_address (xop0, byte_mode, + plus_constant (XEXP (xop0, 0), xoffset)); + + volatile_ok = save_volatile_ok; + } + + /* If op0 is a register, we need it in MAXMODE (which is usually + SImode). to make it acceptable to the format of extzv. */ + if (GET_CODE (xop0) == SUBREG && GET_MODE (xop0) != maxmode) + abort (); + if (GET_CODE (xop0) == REG && GET_MODE (xop0) != maxmode) + xop0 = gen_rtx (SUBREG, maxmode, xop0, 0); + + /* On big-endian machines, we count bits from the most significant. + If the bit field insn does not, we must invert. */ + if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN) + xbitpos = unit - bitsize - xbitpos; + + /* Now convert from counting within UNIT to counting in MAXMODE. */ + if (BITS_BIG_ENDIAN && GET_CODE (xop0) != MEM) + xbitpos += GET_MODE_BITSIZE (maxmode) - unit; + + unit = GET_MODE_BITSIZE (maxmode); + + if (xtarget == 0 + || (flag_force_mem && GET_CODE (xtarget) == MEM)) + xtarget = xspec_target = gen_reg_rtx (tmode); + + if (GET_MODE (xtarget) != maxmode) + { + if (GET_CODE (xtarget) == REG) + { + int wider = (GET_MODE_SIZE (maxmode) + > GET_MODE_SIZE (GET_MODE (xtarget))); + xtarget = gen_lowpart (maxmode, xtarget); + if (wider) + xspec_target_subreg = xtarget; + } + else + xtarget = gen_reg_rtx (maxmode); + } + + /* If this machine's extzv insists on a register target, + make sure we have one. */ + if (! ((*insn_operand_predicate[(int) CODE_FOR_extzv][0]) + (xtarget, maxmode))) + xtarget = gen_reg_rtx (maxmode); + + bitsize_rtx = GEN_INT (bitsize); + bitpos_rtx = GEN_INT (xbitpos); + + pat = gen_extzv (protect_from_queue (xtarget, 1), + xop0, bitsize_rtx, bitpos_rtx); + if (pat) + { + emit_insn (pat); + target = xtarget; + spec_target = xspec_target; + spec_target_subreg = xspec_target_subreg; + } + else + { + delete_insns_since (last); + target = extract_fixed_bit_field (tmode, op0, offset, bitsize, + bitpos, target, 1, align); + } + } + else + extzv_loses: +#endif + target = extract_fixed_bit_field (tmode, op0, offset, bitsize, bitpos, + target, 1, align); + } + else + { +#ifdef HAVE_extv + if (HAVE_extv + && (GET_MODE_BITSIZE (insn_operand_mode[(int) CODE_FOR_extv][0]) + >= bitsize) + && ! ((GET_CODE (op0) == REG || GET_CODE (op0) == SUBREG) + && (bitsize + bitpos + > GET_MODE_BITSIZE (insn_operand_mode[(int) CODE_FOR_extv][0])))) + { + int xbitpos = bitpos, xoffset = offset; + rtx bitsize_rtx, bitpos_rtx; + rtx last = get_last_insn(); + rtx xop0 = op0, xtarget = target; + rtx xspec_target = spec_target; + rtx xspec_target_subreg = spec_target_subreg; + rtx pat; + enum machine_mode maxmode + = insn_operand_mode[(int) CODE_FOR_extv][0]; + + if (GET_CODE (xop0) == MEM) + { + /* Is the memory operand acceptable? */ + if (! ((*insn_operand_predicate[(int) CODE_FOR_extv][1]) + (xop0, GET_MODE (xop0)))) + { + /* No, load into a reg and extract from there. */ + enum machine_mode bestmode; + + /* Get the mode to use for inserting into this field. If + OP0 is BLKmode, get the smallest mode consistent with the + alignment. If OP0 is a non-BLKmode object that is no + wider than MAXMODE, use its mode. Otherwise, use the + smallest mode containing the field. */ + + if (GET_MODE (xop0) == BLKmode + || (GET_MODE_SIZE (GET_MODE (op0)) + > GET_MODE_SIZE (maxmode))) + bestmode = get_best_mode (bitsize, bitnum, + align * BITS_PER_UNIT, maxmode, + MEM_VOLATILE_P (xop0)); + else + bestmode = GET_MODE (xop0); + + if (bestmode == VOIDmode + || (SLOW_UNALIGNED_ACCESS && GET_MODE_SIZE (bestmode) > align)) + goto extv_loses; + + /* Compute offset as multiple of this unit, + counting in bytes. */ + unit = GET_MODE_BITSIZE (bestmode); + xoffset = (bitnum / unit) * GET_MODE_SIZE (bestmode); + xbitpos = bitnum % unit; + xop0 = change_address (xop0, bestmode, + plus_constant (XEXP (xop0, 0), + xoffset)); + /* Fetch it to a register in that size. */ + xop0 = force_reg (bestmode, xop0); + + /* XBITPOS counts within UNIT, which is what is expected. */ + } + else + /* Get ref to first byte containing part of the field. */ + xop0 = change_address (xop0, byte_mode, + plus_constant (XEXP (xop0, 0), xoffset)); + } + + /* If op0 is a register, we need it in MAXMODE (which is usually + SImode) to make it acceptable to the format of extv. */ + if (GET_CODE (xop0) == SUBREG && GET_MODE (xop0) != maxmode) + abort (); + if (GET_CODE (xop0) == REG && GET_MODE (xop0) != maxmode) + xop0 = gen_rtx (SUBREG, maxmode, xop0, 0); + + /* On big-endian machines, we count bits from the most significant. + If the bit field insn does not, we must invert. */ + if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN) + xbitpos = unit - bitsize - xbitpos; + + /* XBITPOS counts within a size of UNIT. + Adjust to count within a size of MAXMODE. */ + if (BITS_BIG_ENDIAN && GET_CODE (xop0) != MEM) + xbitpos += (GET_MODE_BITSIZE (maxmode) - unit); + + unit = GET_MODE_BITSIZE (maxmode); + + if (xtarget == 0 + || (flag_force_mem && GET_CODE (xtarget) == MEM)) + xtarget = xspec_target = gen_reg_rtx (tmode); + + if (GET_MODE (xtarget) != maxmode) + { + if (GET_CODE (xtarget) == REG) + { + int wider = (GET_MODE_SIZE (maxmode) + > GET_MODE_SIZE (GET_MODE (xtarget))); + xtarget = gen_lowpart (maxmode, xtarget); + if (wider) + xspec_target_subreg = xtarget; + } + else + xtarget = gen_reg_rtx (maxmode); + } + + /* If this machine's extv insists on a register target, + make sure we have one. */ + if (! ((*insn_operand_predicate[(int) CODE_FOR_extv][0]) + (xtarget, maxmode))) + xtarget = gen_reg_rtx (maxmode); + + bitsize_rtx = GEN_INT (bitsize); + bitpos_rtx = GEN_INT (xbitpos); + + pat = gen_extv (protect_from_queue (xtarget, 1), + xop0, bitsize_rtx, bitpos_rtx); + if (pat) + { + emit_insn (pat); + target = xtarget; + spec_target = xspec_target; + spec_target_subreg = xspec_target_subreg; + } + else + { + delete_insns_since (last); + target = extract_fixed_bit_field (tmode, op0, offset, bitsize, + bitpos, target, 0, align); + } + } + else + extv_loses: +#endif + target = extract_fixed_bit_field (tmode, op0, offset, bitsize, bitpos, + target, 0, align); + } + if (target == spec_target) + return target; + if (target == spec_target_subreg) + return spec_target; + if (GET_MODE (target) != tmode && GET_MODE (target) != mode) + { + /* If the target mode is floating-point, first convert to the + integer mode of that size and then access it as a floating-point + value via a SUBREG. */ + if (GET_MODE_CLASS (tmode) == MODE_FLOAT) + { + target = convert_to_mode (mode_for_size (GET_MODE_BITSIZE (tmode), + MODE_INT, 0), + target, unsignedp); + if (GET_CODE (target) != REG) + target = copy_to_reg (target); + return gen_rtx (SUBREG, tmode, target, 0); + } + else + return convert_to_mode (tmode, target, unsignedp); + } + return target; +} + +/* Extract a bit field using shifts and boolean operations + Returns an rtx to represent the value. + OP0 addresses a register (word) or memory (byte). + BITPOS says which bit within the word or byte the bit field starts in. + OFFSET says how many bytes farther the bit field starts; + it is 0 if OP0 is a register. + BITSIZE says how many bits long the bit field is. + (If OP0 is a register, it may be narrower than a full word, + but BITPOS still counts within a full word, + which is significant on bigendian machines.) + + UNSIGNEDP is nonzero for an unsigned bit field (don't sign-extend value). + If TARGET is nonzero, attempts to store the value there + and return TARGET, but this is not guaranteed. + If TARGET is not used, create a pseudo-reg of mode TMODE for the value. + + ALIGN is the alignment that STR_RTX is known to have, measured in bytes. */ + +static rtx +extract_fixed_bit_field (tmode, op0, offset, bitsize, bitpos, + target, unsignedp, align) + enum machine_mode tmode; + register rtx op0, target; + register int offset, bitsize, bitpos; + int unsignedp; + int align; +{ + int total_bits = BITS_PER_WORD; + enum machine_mode mode; + + if (GET_CODE (op0) == SUBREG || GET_CODE (op0) == REG) + { + /* Special treatment for a bit field split across two registers. */ + if (bitsize + bitpos > BITS_PER_WORD) + return extract_split_bit_field (op0, bitsize, bitpos, + unsignedp, align); + } + else + { + /* Get the proper mode to use for this field. We want a mode that + includes the entire field. If such a mode would be larger than + a word, we won't be doing the extraction the normal way. */ + + mode = get_best_mode (bitsize, bitpos + offset * BITS_PER_UNIT, + align * BITS_PER_UNIT, word_mode, + GET_CODE (op0) == MEM && MEM_VOLATILE_P (op0)); + + if (mode == VOIDmode) + /* The only way this should occur is if the field spans word + boundaries. */ + return extract_split_bit_field (op0, bitsize, + bitpos + offset * BITS_PER_UNIT, + unsignedp, align); + + total_bits = GET_MODE_BITSIZE (mode); + + /* Make sure bitpos is valid for the chosen mode. Adjust BITPOS to + be be in the range 0 to total_bits-1, and put any excess bytes in + OFFSET. */ + if (bitpos >= total_bits) + { + offset += (bitpos / total_bits) * (total_bits / BITS_PER_UNIT); + bitpos -= ((bitpos / total_bits) * (total_bits / BITS_PER_UNIT) + * BITS_PER_UNIT); + } + + /* Get ref to an aligned byte, halfword, or word containing the field. + Adjust BITPOS to be position within a word, + and OFFSET to be the offset of that word. + Then alter OP0 to refer to that word. */ + bitpos += (offset % (total_bits / BITS_PER_UNIT)) * BITS_PER_UNIT; + offset -= (offset % (total_bits / BITS_PER_UNIT)); + op0 = change_address (op0, mode, + plus_constant (XEXP (op0, 0), offset)); + } + + mode = GET_MODE (op0); + + if (BYTES_BIG_ENDIAN) + { + /* BITPOS is the distance between our msb and that of OP0. + Convert it to the distance from the lsb. */ + + bitpos = total_bits - bitsize - bitpos; + } + + /* Now BITPOS is always the distance between the field's lsb and that of OP0. + We have reduced the big-endian case to the little-endian case. */ + + if (unsignedp) + { + if (bitpos) + { + /* If the field does not already start at the lsb, + shift it so it does. */ + tree amount = build_int_2 (bitpos, 0); + /* Maybe propagate the target for the shift. */ + /* But not if we will return it--could confuse integrate.c. */ + rtx subtarget = (target != 0 && GET_CODE (target) == REG + && !REG_FUNCTION_VALUE_P (target) + ? target : 0); + if (tmode != mode) subtarget = 0; + op0 = expand_shift (RSHIFT_EXPR, mode, op0, amount, subtarget, 1); + } + /* Convert the value to the desired mode. */ + if (mode != tmode) + op0 = convert_to_mode (tmode, op0, 1); + + /* Unless the msb of the field used to be the msb when we shifted, + mask out the upper bits. */ + + if (GET_MODE_BITSIZE (mode) != bitpos + bitsize +#if 0 +#ifdef SLOW_ZERO_EXTEND + /* Always generate an `and' if + we just zero-extended op0 and SLOW_ZERO_EXTEND, since it + will combine fruitfully with the zero-extend. */ + || tmode != mode +#endif +#endif + ) + return expand_binop (GET_MODE (op0), and_optab, op0, + mask_rtx (GET_MODE (op0), 0, bitsize, 0), + target, 1, OPTAB_LIB_WIDEN); + return op0; + } + + /* To extract a signed bit-field, first shift its msb to the msb of the word, + then arithmetic-shift its lsb to the lsb of the word. */ + op0 = force_reg (mode, op0); + if (mode != tmode) + target = 0; + + /* Find the narrowest integer mode that contains the field. */ + + for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode; + mode = GET_MODE_WIDER_MODE (mode)) + if (GET_MODE_BITSIZE (mode) >= bitsize + bitpos) + { + op0 = convert_to_mode (mode, op0, 0); + break; + } + + if (GET_MODE_BITSIZE (mode) != (bitsize + bitpos)) + { + tree amount = build_int_2 (GET_MODE_BITSIZE (mode) - (bitsize + bitpos), 0); + /* Maybe propagate the target for the shift. */ + /* But not if we will return the result--could confuse integrate.c. */ + rtx subtarget = (target != 0 && GET_CODE (target) == REG + && ! REG_FUNCTION_VALUE_P (target) + ? target : 0); + op0 = expand_shift (LSHIFT_EXPR, mode, op0, amount, subtarget, 1); + } + + return expand_shift (RSHIFT_EXPR, mode, op0, + build_int_2 (GET_MODE_BITSIZE (mode) - bitsize, 0), + target, 0); +} + +/* Return a constant integer (CONST_INT or CONST_DOUBLE) mask value + of mode MODE with BITSIZE ones followed by BITPOS zeros, or the + complement of that if COMPLEMENT. The mask is truncated if + necessary to the width of mode MODE. The mask is zero-extended if + BITSIZE+BITPOS is too small for MODE. */ + +static rtx +mask_rtx (mode, bitpos, bitsize, complement) + enum machine_mode mode; + int bitpos, bitsize, complement; +{ + HOST_WIDE_INT masklow, maskhigh; + + if (bitpos < HOST_BITS_PER_WIDE_INT) + masklow = (HOST_WIDE_INT) -1 << bitpos; + else + masklow = 0; + + if (bitpos + bitsize < HOST_BITS_PER_WIDE_INT) + masklow &= ((unsigned HOST_WIDE_INT) -1 + >> (HOST_BITS_PER_WIDE_INT - bitpos - bitsize)); + + if (bitpos <= HOST_BITS_PER_WIDE_INT) + maskhigh = -1; + else + maskhigh = (HOST_WIDE_INT) -1 << (bitpos - HOST_BITS_PER_WIDE_INT); + + if (bitpos + bitsize > HOST_BITS_PER_WIDE_INT) + maskhigh &= ((unsigned HOST_WIDE_INT) -1 + >> (2 * HOST_BITS_PER_WIDE_INT - bitpos - bitsize)); + else + maskhigh = 0; + + if (complement) + { + maskhigh = ~maskhigh; + masklow = ~masklow; + } + + return immed_double_const (masklow, maskhigh, mode); +} + +/* Return a constant integer (CONST_INT or CONST_DOUBLE) rtx with the value + VALUE truncated to BITSIZE bits and then shifted left BITPOS bits. */ + +static rtx +lshift_value (mode, value, bitpos, bitsize) + enum machine_mode mode; + rtx value; + int bitpos, bitsize; +{ + unsigned HOST_WIDE_INT v = INTVAL (value); + HOST_WIDE_INT low, high; + + if (bitsize < HOST_BITS_PER_WIDE_INT) + v &= ~((HOST_WIDE_INT) -1 << bitsize); + + if (bitpos < HOST_BITS_PER_WIDE_INT) + { + low = v << bitpos; + high = (bitpos > 0 ? (v >> (HOST_BITS_PER_WIDE_INT - bitpos)) : 0); + } + else + { + low = 0; + high = v << (bitpos - HOST_BITS_PER_WIDE_INT); + } + + return immed_double_const (low, high, mode); +} + +/* Extract a bit field that is split across two words + and return an RTX for the result. + + OP0 is the REG, SUBREG or MEM rtx for the first of the two words. + BITSIZE is the field width; BITPOS, position of its first bit, in the word. + UNSIGNEDP is 1 if should zero-extend the contents; else sign-extend. + + ALIGN is the known alignment of OP0, measured in bytes. + This is also the size of the memory objects to be used. */ + +static rtx +extract_split_bit_field (op0, bitsize, bitpos, unsignedp, align) + rtx op0; + int bitsize, bitpos, unsignedp, align; +{ + int unit; + int bitsdone = 0; + rtx result; + int first = 1; + + /* Make sure UNIT isn't larger than BITS_PER_WORD, we can only handle that + much at a time. */ + if (GET_CODE (op0) == REG || GET_CODE (op0) == SUBREG) + unit = BITS_PER_WORD; + else + unit = MIN (align * BITS_PER_UNIT, BITS_PER_WORD); + + while (bitsdone < bitsize) + { + int thissize; + rtx part, word; + int thispos; + int offset; + + offset = (bitpos + bitsdone) / unit; + thispos = (bitpos + bitsdone) % unit; + + /* THISSIZE must not overrun a word boundary. Otherwise, + extract_fixed_bit_field will call us again, and we will mutually + recurse forever. */ + thissize = MIN (bitsize - bitsdone, BITS_PER_WORD); + thissize = MIN (thissize, unit - thispos); + + /* If OP0 is a register, then handle OFFSET here. + + When handling multiword bitfields, extract_bit_field may pass + down a word_mode SUBREG of a larger REG for a bitfield that actually + crosses a word boundary. Thus, for a SUBREG, we must find + the current word starting from the base register. */ + if (GET_CODE (op0) == SUBREG) + { + word = operand_subword_force (SUBREG_REG (op0), + SUBREG_WORD (op0) + offset, + GET_MODE (SUBREG_REG (op0))); + offset = 0; + } + else if (GET_CODE (op0) == REG) + { + word = operand_subword_force (op0, offset, GET_MODE (op0)); + offset = 0; + } + else + word = op0; + + /* Extract the parts in bit-counting order, + whose meaning is determined by BYTES_PER_UNIT. + OFFSET is in UNITs, and UNIT is in bits. + extract_fixed_bit_field wants offset in bytes. */ + part = extract_fixed_bit_field (word_mode, word, + offset * unit / BITS_PER_UNIT, + thissize, thispos, 0, 1, align); + bitsdone += thissize; + + /* Shift this part into place for the result. */ + if (BYTES_BIG_ENDIAN) + { + if (bitsize != bitsdone) + part = expand_shift (LSHIFT_EXPR, word_mode, part, + build_int_2 (bitsize - bitsdone, 0), 0, 1); + } + else + { + if (bitsdone != thissize) + part = expand_shift (LSHIFT_EXPR, word_mode, part, + build_int_2 (bitsdone - thissize, 0), 0, 1); + } + + if (first) + result = part; + else + /* Combine the parts with bitwise or. This works + because we extracted each part as an unsigned bit field. */ + result = expand_binop (word_mode, ior_optab, part, result, NULL_RTX, 1, + OPTAB_LIB_WIDEN); + + first = 0; + } + + /* Unsigned bit field: we are done. */ + if (unsignedp) + return result; + /* Signed bit field: sign-extend with two arithmetic shifts. */ + result = expand_shift (LSHIFT_EXPR, word_mode, result, + build_int_2 (BITS_PER_WORD - bitsize, 0), + NULL_RTX, 0); + return expand_shift (RSHIFT_EXPR, word_mode, result, + build_int_2 (BITS_PER_WORD - bitsize, 0), NULL_RTX, 0); +} + +/* Add INC into TARGET. */ + +void +expand_inc (target, inc) + rtx target, inc; +{ + rtx value = expand_binop (GET_MODE (target), add_optab, + target, inc, + target, 0, OPTAB_LIB_WIDEN); + if (value != target) + emit_move_insn (target, value); +} + +/* Subtract DEC from TARGET. */ + +void +expand_dec (target, dec) + rtx target, dec; +{ + rtx value = expand_binop (GET_MODE (target), sub_optab, + target, dec, + target, 0, OPTAB_LIB_WIDEN); + if (value != target) + emit_move_insn (target, value); +} + +/* Output a shift instruction for expression code CODE, + with SHIFTED being the rtx for the value to shift, + and AMOUNT the tree for the amount to shift by. + Store the result in the rtx TARGET, if that is convenient. + If UNSIGNEDP is nonzero, do a logical shift; otherwise, arithmetic. + Return the rtx for where the value is. */ + +rtx +expand_shift (code, mode, shifted, amount, target, unsignedp) + enum tree_code code; + register enum machine_mode mode; + rtx shifted; + tree amount; + register rtx target; + int unsignedp; +{ + register rtx op1, temp = 0; + register int left = (code == LSHIFT_EXPR || code == LROTATE_EXPR); + register int rotate = (code == LROTATE_EXPR || code == RROTATE_EXPR); + int try; + + /* Previously detected shift-counts computed by NEGATE_EXPR + and shifted in the other direction; but that does not work + on all machines. */ + + op1 = expand_expr (amount, NULL_RTX, VOIDmode, 0); + +#ifdef SHIFT_COUNT_TRUNCATED + if (SHIFT_COUNT_TRUNCATED + && GET_CODE (op1) == CONST_INT + && (unsigned HOST_WIDE_INT) INTVAL (op1) >= GET_MODE_BITSIZE (mode)) + op1 = GEN_INT ((unsigned HOST_WIDE_INT) INTVAL (op1) + % GET_MODE_BITSIZE (mode)); +#endif + + if (op1 == const0_rtx) + return shifted; + + for (try = 0; temp == 0 && try < 3; try++) + { + enum optab_methods methods; + + if (try == 0) + methods = OPTAB_DIRECT; + else if (try == 1) + methods = OPTAB_WIDEN; + else + methods = OPTAB_LIB_WIDEN; + + if (rotate) + { + /* Widening does not work for rotation. */ + if (methods == OPTAB_WIDEN) + continue; + else if (methods == OPTAB_LIB_WIDEN) + { + /* If we have been unable to open-code this by a rotation, + do it as the IOR of two shifts. I.e., to rotate A + by N bits, compute (A << N) | ((unsigned) A >> (C - N)) + where C is the bitsize of A. + + It is theoretically possible that the target machine might + not be able to perform either shift and hence we would + be making two libcalls rather than just the one for the + shift (similarly if IOR could not be done). We will allow + this extremely unlikely lossage to avoid complicating the + code below. */ + + rtx subtarget = target == shifted ? 0 : target; + rtx temp1; + tree type = TREE_TYPE (amount); + tree new_amount = make_tree (type, op1); + tree other_amount + = fold (build (MINUS_EXPR, type, + convert (type, + build_int_2 (GET_MODE_BITSIZE (mode), + 0)), + amount)); + + shifted = force_reg (mode, shifted); + + temp = expand_shift (left ? LSHIFT_EXPR : RSHIFT_EXPR, + mode, shifted, new_amount, subtarget, 1); + temp1 = expand_shift (left ? RSHIFT_EXPR : LSHIFT_EXPR, + mode, shifted, other_amount, 0, 1); + return expand_binop (mode, ior_optab, temp, temp1, target, + unsignedp, methods); + } + + temp = expand_binop (mode, + left ? rotl_optab : rotr_optab, + shifted, op1, target, unsignedp, methods); + + /* If we don't have the rotate, but we are rotating by a constant + that is in range, try a rotate in the opposite direction. */ + + if (temp == 0 && GET_CODE (op1) == CONST_INT + && INTVAL (op1) > 0 && INTVAL (op1) < GET_MODE_BITSIZE (mode)) + temp = expand_binop (mode, + left ? rotr_optab : rotl_optab, + shifted, + GEN_INT (GET_MODE_BITSIZE (mode) + - INTVAL (op1)), + target, unsignedp, methods); + } + else if (unsignedp) + temp = expand_binop (mode, + left ? ashl_optab : lshr_optab, + shifted, op1, target, unsignedp, methods); + + /* Do arithmetic shifts. + Also, if we are going to widen the operand, we can just as well + use an arithmetic right-shift instead of a logical one. */ + if (temp == 0 && ! rotate + && (! unsignedp || (! left && methods == OPTAB_WIDEN))) + { + enum optab_methods methods1 = methods; + + /* If trying to widen a log shift to an arithmetic shift, + don't accept an arithmetic shift of the same size. */ + if (unsignedp) + methods1 = OPTAB_MUST_WIDEN; + + /* Arithmetic shift */ + + temp = expand_binop (mode, + left ? ashl_optab : ashr_optab, + shifted, op1, target, unsignedp, methods1); + } + + /* We used to try extzv here for logical right shifts, but that was + only useful for one machine, the VAX, and caused poor code + generation there for lshrdi3, so the code was deleted and a + define_expand for lshrsi3 was added to vax.md. */ + } + + if (temp == 0) + abort (); + return temp; +} + +enum alg_code { alg_zero, alg_m, alg_shift, + alg_add_t_m2, alg_sub_t_m2, + alg_add_factor, alg_sub_factor, + alg_add_t2_m, alg_sub_t2_m, + alg_add, alg_subtract, alg_factor, alg_shiftop }; + +/* This structure records a sequence of operations. + `ops' is the number of operations recorded. + `cost' is their total cost. + The operations are stored in `op' and the corresponding + logarithms of the integer coefficients in `log'. + + These are the operations: + alg_zero total := 0; + alg_m total := multiplicand; + alg_shift total := total * coeff + alg_add_t_m2 total := total + multiplicand * coeff; + alg_sub_t_m2 total := total - multiplicand * coeff; + alg_add_factor total := total * coeff + total; + alg_sub_factor total := total * coeff - total; + alg_add_t2_m total := total * coeff + multiplicand; + alg_sub_t2_m total := total * coeff - multiplicand; + + The first operand must be either alg_zero or alg_m. */ + +struct algorithm +{ + short cost; + short ops; + /* The size of the OP and LOG fields are not directly related to the + word size, but the worst-case algorithms will be if we have few + consecutive ones or zeros, i.e., a multiplicand like 10101010101... + In that case we will generate shift-by-2, add, shift-by-2, add,..., + in total wordsize operations. */ + enum alg_code op[MAX_BITS_PER_WORD]; + char log[MAX_BITS_PER_WORD]; +}; + +/* Compute and return the best algorithm for multiplying by T. + The algorithm must cost less than cost_limit + If retval.cost >= COST_LIMIT, no algorithm was found and all + other field of the returned struct are undefined. */ + +static void +synth_mult (alg_out, t, cost_limit) + struct algorithm *alg_out; + unsigned HOST_WIDE_INT t; + int cost_limit; +{ + int m; + struct algorithm *alg_in, *best_alg; + unsigned int cost; + unsigned HOST_WIDE_INT q; + + /* Indicate that no algorithm is yet found. If no algorithm + is found, this value will be returned and indicate failure. */ + alg_out->cost = cost_limit; + + if (cost_limit <= 0) + return; + + /* t == 1 can be done in zero cost. */ + if (t == 1) + { + alg_out->ops = 1; + alg_out->cost = 0; + alg_out->op[0] = alg_m; + return; + } + + /* t == 0 sometimes has a cost. If it does and it exceeds our limit, + fail now. */ + if (t == 0) + { + if (zero_cost >= cost_limit) + return; + else + { + alg_out->ops = 1; + alg_out->cost = zero_cost; + alg_out->op[0] = alg_zero; + return; + } + } + + /* We'll be needing a couple extra algorithm structures now. */ + + alg_in = (struct algorithm *)alloca (sizeof (struct algorithm)); + best_alg = (struct algorithm *)alloca (sizeof (struct algorithm)); + + /* If we have a group of zero bits at the low-order part of T, try + multiplying by the remaining bits and then doing a shift. */ + + if ((t & 1) == 0) + { + m = floor_log2 (t & -t); /* m = number of low zero bits */ + q = t >> m; + cost = shift_cost[m]; + synth_mult (alg_in, q, cost_limit - cost); + + cost += alg_in->cost; + if (cost < cost_limit) + { + struct algorithm *x; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_shift; + cost_limit = cost; + } + } + + /* If we have an odd number, add or subtract one. */ + if ((t & 1) != 0) + { + unsigned HOST_WIDE_INT w; + + for (w = 1; (w & t) != 0; w <<= 1) + ; + if (w > 2 + /* Reject the case where t is 3. + Thus we prefer addition in that case. */ + && t != 3) + { + /* T ends with ...111. Multiply by (T + 1) and subtract 1. */ + + cost = add_cost; + synth_mult (alg_in, t + 1, cost_limit - cost); + + cost += alg_in->cost; + if (cost < cost_limit) + { + struct algorithm *x; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = 0; + best_alg->op[best_alg->ops] = alg_sub_t_m2; + cost_limit = cost; + } + } + else + { + /* T ends with ...01 or ...011. Multiply by (T - 1) and add 1. */ + + cost = add_cost; + synth_mult (alg_in, t - 1, cost_limit - cost); + + cost += alg_in->cost; + if (cost < cost_limit) + { + struct algorithm *x; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = 0; + best_alg->op[best_alg->ops] = alg_add_t_m2; + cost_limit = cost; + } + } + } + + /* Look for factors of t of the form + t = q(2**m +- 1), 2 <= m <= floor(log2(t - 1)). + If we find such a factor, we can multiply by t using an algorithm that + multiplies by q, shift the result by m and add/subtract it to itself. + + We search for large factors first and loop down, even if large factors + are less probable than small; if we find a large factor we will find a + good sequence quickly, and therefore be able to prune (by decreasing + COST_LIMIT) the search. */ + + for (m = floor_log2 (t - 1); m >= 2; m--) + { + unsigned HOST_WIDE_INT d; + + d = ((unsigned HOST_WIDE_INT) 1 << m) + 1; + if (t % d == 0 && t > d) + { + cost = MIN (shiftadd_cost[m], add_cost + shift_cost[m]); + synth_mult (alg_in, t / d, cost_limit - cost); + + cost += alg_in->cost; + if (cost < cost_limit) + { + struct algorithm *x; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_add_factor; + cost_limit = cost; + } + /* Other factors will have been taken care of in the recursion. */ + break; + } + + d = ((unsigned HOST_WIDE_INT) 1 << m) - 1; + if (t % d == 0 && t > d) + { + cost = MIN (shiftsub_cost[m], add_cost + shift_cost[m]); + synth_mult (alg_in, t / d, cost_limit - cost); + + cost += alg_in->cost; + if (cost < cost_limit) + { + struct algorithm *x; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_sub_factor; + cost_limit = cost; + } + break; + } + } + + /* Try shift-and-add (load effective address) instructions, + i.e. do a*3, a*5, a*9. */ + if ((t & 1) != 0) + { + q = t - 1; + q = q & -q; + m = exact_log2 (q); + if (m >= 0) + { + cost = shiftadd_cost[m]; + synth_mult (alg_in, (t - 1) >> m, cost_limit - cost); + + cost += alg_in->cost; + if (cost < cost_limit) + { + struct algorithm *x; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_add_t2_m; + cost_limit = cost; + } + } + + q = t + 1; + q = q & -q; + m = exact_log2 (q); + if (m >= 0) + { + cost = shiftsub_cost[m]; + synth_mult (alg_in, (t + 1) >> m, cost_limit - cost); + + cost += alg_in->cost; + if (cost < cost_limit) + { + struct algorithm *x; + x = alg_in, alg_in = best_alg, best_alg = x; + best_alg->log[best_alg->ops] = m; + best_alg->op[best_alg->ops] = alg_sub_t2_m; + cost_limit = cost; + } + } + } + + /* If cost_limit has not decreased since we stored it in alg_out->cost, + we have not found any algorithm. */ + if (cost_limit == alg_out->cost) + return; + + /* If we are getting a too long sequence for `struct algorithm' + to record, make this search fail. */ + if (best_alg->ops == MAX_BITS_PER_WORD) + return; + + /* Copy the algorithm from temporary space to the space at alg_out. + We avoid using structure assignment because the majority of + best_alg is normally undefined, and this is a critical function. */ + alg_out->ops = best_alg->ops + 1; + alg_out->cost = cost_limit; + bcopy ((char *) best_alg->op, (char *) alg_out->op, + alg_out->ops * sizeof *alg_out->op); + bcopy ((char *) best_alg->log, (char *) alg_out->log, + alg_out->ops * sizeof *alg_out->log); +} + +/* Perform a multiplication and return an rtx for the result. + MODE is mode of value; OP0 and OP1 are what to multiply (rtx's); + TARGET is a suggestion for where to store the result (an rtx). + + We check specially for a constant integer as OP1. + If you want this check for OP0 as well, then before calling + you should swap the two operands if OP0 would be constant. */ + +rtx +expand_mult (mode, op0, op1, target, unsignedp) + enum machine_mode mode; + register rtx op0, op1, target; + int unsignedp; +{ + rtx const_op1 = op1; + + /* synth_mult does an `unsigned int' multiply. As long as the mode is + less than or equal in size to `unsigned int' this doesn't matter. + If the mode is larger than `unsigned int', then synth_mult works only + if the constant value exactly fits in an `unsigned int' without any + truncation. This means that multiplying by negative values does + not work; results are off by 2^32 on a 32 bit machine. */ + + /* If we are multiplying in DImode, it may still be a win + to try to work with shifts and adds. */ + if (GET_CODE (op1) == CONST_DOUBLE + && GET_MODE_CLASS (GET_MODE (op1)) == MODE_INT + && HOST_BITS_PER_INT >= BITS_PER_WORD + && CONST_DOUBLE_HIGH (op1) == 0) + const_op1 = GEN_INT (CONST_DOUBLE_LOW (op1)); + else if (HOST_BITS_PER_INT < GET_MODE_BITSIZE (mode) + && GET_CODE (op1) == CONST_INT + && INTVAL (op1) < 0) + const_op1 = 0; + + /* We used to test optimize here, on the grounds that it's better to + produce a smaller program when -O is not used. + But this causes such a terrible slowdown sometimes + that it seems better to use synth_mult always. */ + + if (const_op1 && GET_CODE (const_op1) == CONST_INT) + { + struct algorithm alg; + struct algorithm alg2; + HOST_WIDE_INT val = INTVAL (op1); + HOST_WIDE_INT val_so_far; + rtx insn; + int mult_cost; + enum {basic_variant, negate_variant, add_variant} variant = basic_variant; + + /* Try to do the computation three ways: multiply by the negative of OP1 + and then negate, do the multiplication directly, or do multiplication + by OP1 - 1. */ + + mult_cost = rtx_cost (gen_rtx (MULT, mode, op0, op1), SET); + mult_cost = MIN (12 * add_cost, mult_cost); + + synth_mult (&alg, val, mult_cost); + + /* This works only if the inverted value actually fits in an + `unsigned int' */ + if (HOST_BITS_PER_INT >= GET_MODE_BITSIZE (mode)) + { + synth_mult (&alg2, - val, + (alg.cost < mult_cost ? alg.cost : mult_cost) - negate_cost); + if (alg2.cost + negate_cost < alg.cost) + alg = alg2, variant = negate_variant; + } + + /* This proves very useful for division-by-constant. */ + synth_mult (&alg2, val - 1, + (alg.cost < mult_cost ? alg.cost : mult_cost) - add_cost); + if (alg2.cost + add_cost < alg.cost) + alg = alg2, variant = add_variant; + + if (alg.cost < mult_cost) + { + /* We found something cheaper than a multiply insn. */ + int opno; + rtx accum, tem; + + op0 = protect_from_queue (op0, 0); + + /* Avoid referencing memory over and over. + For speed, but also for correctness when mem is volatile. */ + if (GET_CODE (op0) == MEM) + op0 = force_reg (mode, op0); + + /* ACCUM starts out either as OP0 or as a zero, depending on + the first operation. */ + + if (alg.op[0] == alg_zero) + { + accum = copy_to_mode_reg (mode, const0_rtx); + val_so_far = 0; + } + else if (alg.op[0] == alg_m) + { + accum = copy_to_mode_reg (mode, op0); + val_so_far = 1; + } + else + abort (); + + for (opno = 1; opno < alg.ops; opno++) + { + int log = alg.log[opno]; + int preserve = preserve_subexpressions_p (); + rtx shift_subtarget = preserve ? 0 : accum; + rtx add_target + = (opno == alg.ops - 1 && target != 0 && variant != add_variant + ? target : 0); + rtx accum_target = preserve ? 0 : accum; + + switch (alg.op[opno]) + { + case alg_shift: + accum = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_2 (log, 0), NULL_RTX, 0); + val_so_far <<= log; + break; + + case alg_add_t_m2: + tem = expand_shift (LSHIFT_EXPR, mode, op0, + build_int_2 (log, 0), NULL_RTX, 0); + accum = force_operand (gen_rtx (PLUS, mode, accum, tem), + add_target ? add_target : accum_target); + val_so_far += (HOST_WIDE_INT) 1 << log; + break; + + case alg_sub_t_m2: + tem = expand_shift (LSHIFT_EXPR, mode, op0, + build_int_2 (log, 0), NULL_RTX, 0); + accum = force_operand (gen_rtx (MINUS, mode, accum, tem), + add_target ? add_target : accum_target); + val_so_far -= (HOST_WIDE_INT) 1 << log; + break; + + case alg_add_t2_m: + accum = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_2 (log, 0), shift_subtarget, + 0); + accum = force_operand (gen_rtx (PLUS, mode, accum, op0), + add_target ? add_target : accum_target); + val_so_far = (val_so_far << log) + 1; + break; + + case alg_sub_t2_m: + accum = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_2 (log, 0), shift_subtarget, + 0); + accum = force_operand (gen_rtx (MINUS, mode, accum, op0), + add_target ? add_target : accum_target); + val_so_far = (val_so_far << log) - 1; + break; + + case alg_add_factor: + tem = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_2 (log, 0), NULL_RTX, 0); + accum = force_operand (gen_rtx (PLUS, mode, accum, tem), + add_target ? add_target : accum_target); + val_so_far += val_so_far << log; + break; + + case alg_sub_factor: + tem = expand_shift (LSHIFT_EXPR, mode, accum, + build_int_2 (log, 0), NULL_RTX, 0); + accum = force_operand (gen_rtx (MINUS, mode, tem, accum), + (add_target ? add_target + : preserve ? 0 : tem)); + val_so_far = (val_so_far << log) - val_so_far; + break; + + default: + abort ();; + } + + /* Write a REG_EQUAL note on the last insn so that we can cse + multiplication sequences. */ + + insn = get_last_insn (); + REG_NOTES (insn) + = gen_rtx (EXPR_LIST, REG_EQUAL, + gen_rtx (MULT, mode, op0, GEN_INT (val_so_far)), + REG_NOTES (insn)); + } + + if (variant == negate_variant) + { + val_so_far = - val_so_far; + accum = expand_unop (mode, neg_optab, accum, target, 0); + } + else if (variant == add_variant) + { + val_so_far = val_so_far + 1; + accum = force_operand (gen_rtx (PLUS, mode, accum, op0), target); + } + + if (val != val_so_far) + abort (); + + return accum; + } + } + + /* This used to use umul_optab if unsigned, but for non-widening multiply + there is no difference between signed and unsigned. */ + op0 = expand_binop (mode, smul_optab, + op0, op1, target, unsignedp, OPTAB_LIB_WIDEN); + if (op0 == 0) + abort (); + return op0; +} + +/* Return the smallest n such that 2**n >= X. */ + +int +ceil_log2 (x) + unsigned HOST_WIDE_INT x; +{ + return floor_log2 (x - 1) + 1; +} + +/* Choose a minimal N + 1 bit approximation to 1/D that can be used to + replace division by D, and put the least significant N bits of the result + in *MULTIPLIER_PTR and return the most significant bit. + + The width of operations is N (should be <= HOST_BITS_PER_WIDE_INT), the + needed precision is in PRECISION (should be <= N). + + PRECISION should be as small as possible so this function can choose + multiplier more freely. + + The rounded-up logarithm of D is placed in *lgup_ptr. A shift count that + is to be used for a final right shift is placed in *POST_SHIFT_PTR. + + Using this function, x/D will be equal to (x * m) >> (*POST_SHIFT_PTR), + where m is the full HOST_BITS_PER_WIDE_INT + 1 bit multiplier. */ + +static +unsigned HOST_WIDE_INT +choose_multiplier (d, n, precision, multiplier_ptr, post_shift_ptr, lgup_ptr) + unsigned HOST_WIDE_INT d; + int n; + int precision; + unsigned HOST_WIDE_INT *multiplier_ptr; + int *post_shift_ptr; + int *lgup_ptr; +{ + unsigned HOST_WIDE_INT mhigh_hi, mhigh_lo; + unsigned HOST_WIDE_INT mlow_hi, mlow_lo; + int lgup, post_shift; + int pow, pow2; + unsigned HOST_WIDE_INT nh, nl, dummy1, dummy2; + + /* lgup = ceil(log2(divisor)); */ + lgup = ceil_log2 (d); + + if (lgup > n) + abort (); + + pow = n + lgup; + pow2 = n + lgup - precision; + + if (pow == 2 * HOST_BITS_PER_WIDE_INT) + { + /* We could handle this with some effort, but this case is much better + handled directly with a scc insn, so rely on caller using that. */ + abort (); + } + + /* mlow = 2^(N + lgup)/d */ + if (pow >= HOST_BITS_PER_WIDE_INT) + { + nh = (unsigned HOST_WIDE_INT) 1 << (pow - HOST_BITS_PER_WIDE_INT); + nl = 0; + } + else + { + nh = 0; + nl = (unsigned HOST_WIDE_INT) 1 << pow; + } + div_and_round_double (TRUNC_DIV_EXPR, 1, nl, nh, d, (HOST_WIDE_INT) 0, + &mlow_lo, &mlow_hi, &dummy1, &dummy2); + + /* mhigh = (2^(N + lgup) + 2^N + lgup - precision)/d */ + if (pow2 >= HOST_BITS_PER_WIDE_INT) + nh |= (unsigned HOST_WIDE_INT) 1 << (pow2 - HOST_BITS_PER_WIDE_INT); + else + nl |= (unsigned HOST_WIDE_INT) 1 << pow2; + div_and_round_double (TRUNC_DIV_EXPR, 1, nl, nh, d, (HOST_WIDE_INT) 0, + &mhigh_lo, &mhigh_hi, &dummy1, &dummy2); + + if (mhigh_hi && nh - d >= d) + abort (); + if (mhigh_hi > 1 || mlow_hi > 1) + abort (); + /* assert that mlow < mhigh. */ + if (! (mlow_hi < mhigh_hi || (mlow_hi == mhigh_hi && mlow_lo < mhigh_lo))) + abort(); + + /* If precision == N, then mlow, mhigh exceed 2^N + (but they do not exceed 2^(N+1)). */ + + /* Reduce to lowest terms */ + for (post_shift = lgup; post_shift > 0; post_shift--) + { + unsigned HOST_WIDE_INT ml_lo = (mlow_hi << (HOST_BITS_PER_WIDE_INT - 1)) | (mlow_lo >> 1); + unsigned HOST_WIDE_INT mh_lo = (mhigh_hi << (HOST_BITS_PER_WIDE_INT - 1)) | (mhigh_lo >> 1); + if (ml_lo >= mh_lo) + break; + + mlow_hi = 0; + mlow_lo = ml_lo; + mhigh_hi = 0; + mhigh_lo = mh_lo; + } + + *post_shift_ptr = post_shift; + *lgup_ptr = lgup; + if (n < HOST_BITS_PER_WIDE_INT) + { + unsigned HOST_WIDE_INT mask = ((unsigned HOST_WIDE_INT) 1 << n) - 1; + *multiplier_ptr = mhigh_lo & mask; + return mhigh_lo >= mask; + } + else + { + *multiplier_ptr = mhigh_lo; + return mhigh_hi; + } +} + +/* Compute the inverse of X mod 2**n, i.e., find Y such that X * Y is + congruent to 1 (mod 2**N). */ + +static unsigned HOST_WIDE_INT +invert_mod2n (x, n) + unsigned HOST_WIDE_INT x; + int n; +{ + /* Solve x*y == 1 (mod 2^n), where x is odd. Return y. */ + + /* The algorithm notes that the choice y = x satisfies + x*y == 1 mod 2^3, since x is assumed odd. + Each iteration doubles the number of bits of significance in y. */ + + unsigned HOST_WIDE_INT mask; + unsigned HOST_WIDE_INT y = x; + int nbit = 3; + + mask = (n == HOST_BITS_PER_WIDE_INT + ? ~(unsigned HOST_WIDE_INT) 0 + : ((unsigned HOST_WIDE_INT) 1 << n) - 1); + + while (nbit < n) + { + y = y * (2 - x*y) & mask; /* Modulo 2^N */ + nbit *= 2; + } + return y; +} + +/* Emit code to adjust ADJ_OPERAND after multiplication of wrong signedness + flavor of OP0 and OP1. ADJ_OPERAND is already the high half of the + product OP0 x OP1. If UNSIGNEDP is nonzero, adjust the signed product + to become unsigned, if UNSIGNEDP is zero, adjust the unsigned product to + become signed. + + The result is put in TARGET if that is convenient. + + MODE is the mode of operation. */ + +rtx +expand_mult_highpart_adjust (mode, adj_operand, op0, op1, target, unsignedp) + enum machine_mode mode; + register rtx adj_operand, op0, op1, target; + int unsignedp; +{ + rtx tem; + enum rtx_code adj_code = unsignedp ? PLUS : MINUS; + + tem = expand_shift (RSHIFT_EXPR, mode, op0, + build_int_2 (GET_MODE_BITSIZE (mode) - 1, 0), + NULL_RTX, 0); + tem = expand_and (tem, op1, NULL_RTX); + adj_operand = force_operand (gen_rtx (adj_code, mode, adj_operand, tem), + adj_operand); + + tem = expand_shift (RSHIFT_EXPR, mode, op1, + build_int_2 (GET_MODE_BITSIZE (mode) - 1, 0), + NULL_RTX, 0); + tem = expand_and (tem, op0, NULL_RTX); + target = force_operand (gen_rtx (adj_code, mode, adj_operand, tem), target); + + return target; +} + +/* Emit code to multiply OP0 and CNST1, putting the high half of the result + in TARGET if that is convenient, and return where the result is. If the + operation can not be performed, 0 is returned. + + MODE is the mode of operation and result. + + UNSIGNEDP nonzero means unsigned multiply. + + MAX_COST is the total allowed cost for the expanded RTL. */ + +rtx +expand_mult_highpart (mode, op0, cnst1, target, unsignedp, max_cost) + enum machine_mode mode; + register rtx op0, target; + unsigned HOST_WIDE_INT cnst1; + int unsignedp; + int max_cost; +{ + enum machine_mode wider_mode = GET_MODE_WIDER_MODE (mode); + optab mul_highpart_optab; + optab moptab; + rtx tem; + int size = GET_MODE_BITSIZE (mode); + rtx op1, wide_op1; + + /* We can't support modes wider than HOST_BITS_PER_INT. */ + if (size > HOST_BITS_PER_WIDE_INT) + abort (); + + op1 = GEN_INT (cnst1); + + if (GET_MODE_BITSIZE (wider_mode) <= HOST_BITS_PER_INT) + wide_op1 = op1; + else + wide_op1 + = immed_double_const (cnst1, + (unsignedp + ? (HOST_WIDE_INT) 0 + : -(cnst1 >> (HOST_BITS_PER_WIDE_INT - 1))), + wider_mode); + + /* expand_mult handles constant multiplication of word_mode + or narrower. It does a poor job for large modes. */ + if (size < BITS_PER_WORD + && mul_cost[(int) wider_mode] + shift_cost[size-1] < max_cost) + { + /* We have to do this, since expand_binop doesn't do conversion for + multiply. Maybe change expand_binop to handle widening multiply? */ + op0 = convert_to_mode (wider_mode, op0, unsignedp); + + tem = expand_mult (wider_mode, op0, wide_op1, NULL_RTX, unsignedp); + tem = expand_shift (RSHIFT_EXPR, wider_mode, tem, + build_int_2 (size, 0), NULL_RTX, 1); + return convert_modes (mode, wider_mode, tem, unsignedp); + } + + if (target == 0) + target = gen_reg_rtx (mode); + + /* Firstly, try using a multiplication insn that only generates the needed + high part of the product, and in the sign flavor of unsignedp. */ + if (mul_highpart_cost[(int) mode] < max_cost) + { + mul_highpart_optab = unsignedp ? umul_highpart_optab : smul_highpart_optab; + target = expand_binop (mode, mul_highpart_optab, + op0, wide_op1, target, unsignedp, OPTAB_DIRECT); + if (target) + return target; + } + + /* Secondly, same as above, but use sign flavor opposite of unsignedp. + Need to adjust the result after the multiplication. */ + if (mul_highpart_cost[(int) mode] + 2 * shift_cost[size-1] + 4 * add_cost < max_cost) + { + mul_highpart_optab = unsignedp ? smul_highpart_optab : umul_highpart_optab; + target = expand_binop (mode, mul_highpart_optab, + op0, wide_op1, target, unsignedp, OPTAB_DIRECT); + if (target) + /* We used the wrong signedness. Adjust the result. */ + return expand_mult_highpart_adjust (mode, target, op0, + op1, target, unsignedp); + } + + /* Try widening multiplication. */ + moptab = unsignedp ? umul_widen_optab : smul_widen_optab; + if (moptab->handlers[(int) wider_mode].insn_code != CODE_FOR_nothing + && mul_widen_cost[(int) wider_mode] < max_cost) + goto try; + + /* Try widening the mode and perform a non-widening multiplication. */ + moptab = smul_optab; + if (smul_optab->handlers[(int) wider_mode].insn_code != CODE_FOR_nothing + && mul_cost[(int) wider_mode] + shift_cost[size-1] < max_cost) + goto try; + + /* Try widening multiplication of opposite signedness, and adjust. */ + moptab = unsignedp ? smul_widen_optab : umul_widen_optab; + if (moptab->handlers[(int) wider_mode].insn_code != CODE_FOR_nothing + && (mul_widen_cost[(int) wider_mode] + + 2 * shift_cost[size-1] + 4 * add_cost < max_cost)) + { + tem = expand_binop (wider_mode, moptab, op0, wide_op1, + NULL_RTX, ! unsignedp, OPTAB_WIDEN); + if (tem != 0) + { + /* Extract the high half of the just generated product. */ + tem = expand_shift (RSHIFT_EXPR, wider_mode, tem, + build_int_2 (size, 0), NULL_RTX, 1); + tem = convert_modes (mode, wider_mode, tem, unsignedp); + /* We used the wrong signedness. Adjust the result. */ + return expand_mult_highpart_adjust (mode, tem, op0, op1, + target, unsignedp); + } + } + + return 0; + + try: + /* Pass NULL_RTX as target since TARGET has wrong mode. */ + tem = expand_binop (wider_mode, moptab, op0, wide_op1, + NULL_RTX, unsignedp, OPTAB_WIDEN); + if (tem == 0) + return 0; + + /* Extract the high half of the just generated product. */ + tem = expand_shift (RSHIFT_EXPR, wider_mode, tem, + build_int_2 (size, 0), NULL_RTX, 1); + return convert_modes (mode, wider_mode, tem, unsignedp); +} + +/* Emit the code to divide OP0 by OP1, putting the result in TARGET + if that is convenient, and returning where the result is. + You may request either the quotient or the remainder as the result; + specify REM_FLAG nonzero to get the remainder. + + CODE is the expression code for which kind of division this is; + it controls how rounding is done. MODE is the machine mode to use. + UNSIGNEDP nonzero means do unsigned division. */ + +/* ??? For CEIL_MOD_EXPR, can compute incorrect remainder with ANDI + and then correct it by or'ing in missing high bits + if result of ANDI is nonzero. + For ROUND_MOD_EXPR, can use ANDI and then sign-extend the result. + This could optimize to a bfexts instruction. + But C doesn't use these operations, so their optimizations are + left for later. */ + +#define EXACT_POWER_OF_2_OR_ZERO_P(x) (((x) & ((x) - 1)) == 0) + +rtx +expand_divmod (rem_flag, code, mode, op0, op1, target, unsignedp) + int rem_flag; + enum tree_code code; + enum machine_mode mode; + register rtx op0, op1, target; + int unsignedp; +{ + enum machine_mode compute_mode; + register rtx tquotient; + rtx quotient = 0, remainder = 0; + rtx last; + int size; + rtx insn, set; + optab optab1, optab2; + int op1_is_constant, op1_is_pow2; + int max_cost, extra_cost; + + op1_is_constant = GET_CODE (op1) == CONST_INT; + op1_is_pow2 = (op1_is_constant + && ((EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1)) + || EXACT_POWER_OF_2_OR_ZERO_P (-INTVAL (op1))))); + + /* + This is the structure of expand_divmod: + + First comes code to fix up the operands so we can perform the operations + correctly and efficiently. + + Second comes a switch statement with code specific for each rounding mode. + For some special operands this code emits all RTL for the desired + operation, for other cases, it generates only a quotient and stores it in + QUOTIENT. The case for trunc division/remainder might leave quotient = 0, + to indicate that it has not done anything. + + Last comes code that finishes the operation. If QUOTIENT is set and + REM_FLAG is set, the remainder is computed as OP0 - QUOTIENT * OP1. If + QUOTIENT is not set, it is computed using trunc rounding. + + We try to generate special code for division and remainder when OP1 is a + constant. If |OP1| = 2**n we can use shifts and some other fast + operations. For other values of OP1, we compute a carefully selected + fixed-point approximation m = 1/OP1, and generate code that multiplies OP0 + by m. + + In all cases but EXACT_DIV_EXPR, this multiplication requires the upper + half of the product. Different strategies for generating the product are + implemented in expand_mult_highpart. + + If what we actually want is the remainder, we generate that by another + by-constant multiplication and a subtraction. */ + + /* We shouldn't be called with OP1 == const1_rtx, but some of the + code below will malfunction if we are, so check here and handle + the special case if so. */ + if (op1 == const1_rtx) + return rem_flag ? const0_rtx : op0; + + if (target + /* Don't use the function value register as a target + since we have to read it as well as write it, + and function-inlining gets confused by this. */ + && ((REG_P (target) && REG_FUNCTION_VALUE_P (target)) + /* Don't clobber an operand while doing a multi-step calculation. */ + || ((rem_flag || op1_is_constant) + && (reg_mentioned_p (target, op0) + || (GET_CODE (op0) == MEM && GET_CODE (target) == MEM))) + || reg_mentioned_p (target, op1) + || (GET_CODE (op1) == MEM && GET_CODE (target) == MEM))) + target = 0; + + /* Get the mode in which to perform this computation. Normally it will + be MODE, but sometimes we can't do the desired operation in MODE. + If so, pick a wider mode in which we can do the operation. Convert + to that mode at the start to avoid repeated conversions. + + First see what operations we need. These depend on the expression + we are evaluating. (We assume that divxx3 insns exist under the + same conditions that modxx3 insns and that these insns don't normally + fail. If these assumptions are not correct, we may generate less + efficient code in some cases.) + + Then see if we find a mode in which we can open-code that operation + (either a division, modulus, or shift). Finally, check for the smallest + mode for which we can do the operation with a library call. */ + + /* We might want to refine this now that we have division-by-constant + optimization. Since expand_mult_highpart tries so many variants, it is + not straightforward to generalize this. Maybe we should make an array + of possible modes in init_expmed? Save this for GCC 2.7. */ + + optab1 = (op1_is_pow2 ? (unsignedp ? lshr_optab : ashr_optab) + : (unsignedp ? udiv_optab : sdiv_optab)); + optab2 = (op1_is_pow2 ? optab1 : (unsignedp ? udivmod_optab : sdivmod_optab)); + + for (compute_mode = mode; compute_mode != VOIDmode; + compute_mode = GET_MODE_WIDER_MODE (compute_mode)) + if (optab1->handlers[(int) compute_mode].insn_code != CODE_FOR_nothing + || optab2->handlers[(int) compute_mode].insn_code != CODE_FOR_nothing) + break; + + if (compute_mode == VOIDmode) + for (compute_mode = mode; compute_mode != VOIDmode; + compute_mode = GET_MODE_WIDER_MODE (compute_mode)) + if (optab1->handlers[(int) compute_mode].libfunc + || optab2->handlers[(int) compute_mode].libfunc) + break; + + /* If we still couldn't find a mode, use MODE, but we'll probably abort + in expand_binop. */ + if (compute_mode == VOIDmode) + compute_mode = mode; + + if (target && GET_MODE (target) == compute_mode) + tquotient = target; + else + tquotient = gen_reg_rtx (compute_mode); + + size = GET_MODE_BITSIZE (compute_mode); +#if 0 + /* It should be possible to restrict the precision to GET_MODE_BITSIZE + (mode), and thereby get better code when OP1 is a constant. Do that + later. It will require going over all usages of SIZE below. */ + size = GET_MODE_BITSIZE (mode); +#endif + + max_cost = div_cost[(int) compute_mode] + - (rem_flag ? mul_cost[(int) compute_mode] + add_cost : 0); + + /* Now convert to the best mode to use. */ + if (compute_mode != mode) + { + op0 = convert_modes (compute_mode, mode, op0, unsignedp); + op1 = convert_modes (compute_mode, mode, op1, unsignedp); + } + + /* If one of the operands is a volatile MEM, copy it into a register. */ + + if (GET_CODE (op0) == MEM && MEM_VOLATILE_P (op0)) + op0 = force_reg (compute_mode, op0); + if (GET_CODE (op1) == MEM && MEM_VOLATILE_P (op1)) + op1 = force_reg (compute_mode, op1); + + /* If we need the remainder or if OP1 is constant, we need to + put OP0 in a register in case it has any queued subexpressions. */ + if (rem_flag || op1_is_constant) + op0 = force_reg (compute_mode, op0); + + last = get_last_insn (); + + /* Promote floor rounding to trunc rounding for unsigned operations. */ + if (unsignedp) + { + if (code == FLOOR_DIV_EXPR) + code = TRUNC_DIV_EXPR; + if (code == FLOOR_MOD_EXPR) + code = TRUNC_MOD_EXPR; + } + + if (op1 != const0_rtx) + switch (code) + { + case TRUNC_MOD_EXPR: + case TRUNC_DIV_EXPR: + if (op1_is_constant && HOST_BITS_PER_WIDE_INT >= size) + { + if (unsignedp) + { + unsigned HOST_WIDE_INT mh, ml; + int pre_shift, post_shift; + int dummy; + unsigned HOST_WIDE_INT d = INTVAL (op1); + + if (EXACT_POWER_OF_2_OR_ZERO_P (d)) + { + pre_shift = floor_log2 (d); + if (rem_flag) + { + remainder = expand_binop (compute_mode, and_optab, op0, + GEN_INT (((HOST_WIDE_INT) 1 << pre_shift) - 1), + remainder, 1, + OPTAB_LIB_WIDEN); + if (remainder) + return gen_lowpart (mode, remainder); + } + quotient = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_2 (pre_shift, 0), + tquotient, 1); + } + else if (d >= ((unsigned HOST_WIDE_INT) 1 << (size - 1))) + { + /* Most significant bit of divisor is set, emit a scc insn. + emit_store_flag needs to be passed a place for the + result. */ + quotient = emit_store_flag (tquotient, GEU, op0, op1, + compute_mode, 1, 1); + if (quotient == 0) + goto fail1; + } + else + { + /* Find a suitable multiplier and right shift count instead + of multiplying with D. */ + + mh = choose_multiplier (d, size, size, + &ml, &post_shift, &dummy); + + /* If the suggested multiplier is more than SIZE bits, we + can do better for even divisors, using an initial right + shift. */ + if (mh != 0 && (d & 1) == 0) + { + pre_shift = floor_log2 (d & -d); + mh = choose_multiplier (d >> pre_shift, size, + size - pre_shift, + &ml, &post_shift, &dummy); + if (mh) + abort (); + } + else + pre_shift = 0; + + if (mh != 0) + { + rtx t1, t2, t3, t4; + + extra_cost = (shift_cost[post_shift - 1] + + shift_cost[1] + 2 * add_cost); + t1 = expand_mult_highpart (compute_mode, op0, ml, + NULL_RTX, 1, + max_cost - extra_cost); + if (t1 == 0) + goto fail1; + t2 = force_operand (gen_rtx (MINUS, compute_mode, + op0, t1), + NULL_RTX); + t3 = expand_shift (RSHIFT_EXPR, compute_mode, t2, + build_int_2 (1, 0), NULL_RTX, 1); + t4 = force_operand (gen_rtx (PLUS, compute_mode, + t1, t3), + NULL_RTX); + quotient = expand_shift (RSHIFT_EXPR, compute_mode, t4, + build_int_2 (post_shift - 1, + 0), + tquotient, 1); + } + else + { + rtx t1, t2; + + t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_2 (pre_shift, 0), + NULL_RTX, 1); + extra_cost = (shift_cost[pre_shift] + + shift_cost[post_shift]); + t2 = expand_mult_highpart (compute_mode, t1, ml, + NULL_RTX, 1, + max_cost - extra_cost); + if (t2 == 0) + goto fail1; + quotient = expand_shift (RSHIFT_EXPR, compute_mode, t2, + build_int_2 (post_shift, 0), + tquotient, 1); + } + } + + insn = get_last_insn (); + if (insn != last + && (set = single_set (insn)) != 0 + && SET_DEST (set) == quotient) + REG_NOTES (insn) + = gen_rtx (EXPR_LIST, REG_EQUAL, + gen_rtx (UDIV, compute_mode, op0, op1), + REG_NOTES (insn)); + } + else /* TRUNC_DIV, signed */ + { + unsigned HOST_WIDE_INT ml; + int lgup, post_shift; + HOST_WIDE_INT d = INTVAL (op1); + unsigned HOST_WIDE_INT abs_d = d >= 0 ? d : -d; + + /* n rem d = n rem -d */ + if (rem_flag && d < 0) + { + d = abs_d; + op1 = GEN_INT (abs_d); + } + + if (d == 1) + quotient = op0; + else if (d == -1) + quotient = expand_unop (compute_mode, neg_optab, op0, + tquotient, 0); + else if (abs_d == (unsigned HOST_WIDE_INT) 1 << (size - 1)) + { + /* This case is not handled correctly below. */ + quotient = emit_store_flag (tquotient, EQ, op0, op1, + compute_mode, 1, 1); + if (quotient == 0) + goto fail1; + } + else if (EXACT_POWER_OF_2_OR_ZERO_P (d) + && (rem_flag ? smod_pow2_cheap : sdiv_pow2_cheap)) + ; + else if (EXACT_POWER_OF_2_OR_ZERO_P (abs_d)) + { + lgup = floor_log2 (abs_d); + if (abs_d != 2 && BRANCH_COST < 3) + { + rtx label = gen_label_rtx (); + rtx t1; + + t1 = copy_to_mode_reg (compute_mode, op0); + emit_cmp_insn (t1, const0_rtx, GE, + NULL_RTX, compute_mode, 0, 0); + emit_jump_insn (gen_bge (label)); + expand_inc (t1, GEN_INT (abs_d - 1)); + emit_label (label); + quotient = expand_shift (RSHIFT_EXPR, compute_mode, t1, + build_int_2 (lgup, 0), + tquotient, 0); + } + else + { + rtx t1, t2, t3; + t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_2 (size - 1, 0), + NULL_RTX, 0); + t2 = expand_shift (RSHIFT_EXPR, compute_mode, t1, + build_int_2 (size - lgup, 0), + NULL_RTX, 1); + t3 = force_operand (gen_rtx (PLUS, compute_mode, + op0, t2), + NULL_RTX); + quotient = expand_shift (RSHIFT_EXPR, compute_mode, t3, + build_int_2 (lgup, 0), + tquotient, 0); + } + + /* We have computed OP0 / abs(OP1). If OP1 is negative, negate + the quotient. */ + if (d < 0) + { + insn = get_last_insn (); + if (insn != last + && (set = single_set (insn)) != 0 + && SET_DEST (set) == quotient) + REG_NOTES (insn) + = gen_rtx (EXPR_LIST, REG_EQUAL, + gen_rtx (DIV, compute_mode, op0, + GEN_INT (abs_d)), + REG_NOTES (insn)); + + quotient = expand_unop (compute_mode, neg_optab, + quotient, quotient, 0); + } + } + else + { + choose_multiplier (abs_d, size, size - 1, + &ml, &post_shift, &lgup); + if (ml < (unsigned HOST_WIDE_INT) 1 << (size - 1)) + { + rtx t1, t2, t3; + + extra_cost = (shift_cost[post_shift] + + shift_cost[size - 1] + add_cost); + t1 = expand_mult_highpart (compute_mode, op0, ml, + NULL_RTX, 0, + max_cost - extra_cost); + if (t1 == 0) + goto fail1; + t2 = expand_shift (RSHIFT_EXPR, compute_mode, t1, + build_int_2 (post_shift, 0), NULL_RTX, 0); + t3 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_2 (size - 1, 0), NULL_RTX, 0); + if (d < 0) + quotient = force_operand (gen_rtx (MINUS, compute_mode, t3, t2), + tquotient); + else + quotient = force_operand (gen_rtx (MINUS, compute_mode, t2, t3), + tquotient); + } + else + { + rtx t1, t2, t3, t4; + + ml |= (~(unsigned HOST_WIDE_INT) 0) << (size - 1); + extra_cost = (shift_cost[post_shift] + + shift_cost[size - 1] + 2 * add_cost); + t1 = expand_mult_highpart (compute_mode, op0, ml, + NULL_RTX, 0, + max_cost - extra_cost); + if (t1 == 0) + goto fail1; + t2 = force_operand (gen_rtx (PLUS, compute_mode, t1, op0), + NULL_RTX); + t3 = expand_shift (RSHIFT_EXPR, compute_mode, t2, + build_int_2 (post_shift, 0), NULL_RTX, 0); + t4 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_2 (size - 1, 0), NULL_RTX, 0); + if (d < 0) + quotient = force_operand (gen_rtx (MINUS, compute_mode, t4, t3), + tquotient); + else + quotient = force_operand (gen_rtx (MINUS, compute_mode, t3, t4), + tquotient); + } + } + + insn = get_last_insn (); + if (insn != last + && (set = single_set (insn)) != 0 + && SET_DEST (set) == quotient) + REG_NOTES (insn) + = gen_rtx (EXPR_LIST, REG_EQUAL, + gen_rtx (DIV, compute_mode, op0, op1), + REG_NOTES (insn)); + } + break; + } + fail1: + delete_insns_since (last); + break; + + case FLOOR_DIV_EXPR: + case FLOOR_MOD_EXPR: + /* We will come here only for signed operations. */ + if (op1_is_constant && HOST_BITS_PER_WIDE_INT >= size) + { + unsigned HOST_WIDE_INT mh, ml; + int pre_shift, lgup, post_shift; + HOST_WIDE_INT d = INTVAL (op1); + + if (d > 0) + { + /* We could just as easily deal with negative constants here, + but it does not seem worth the trouble for GCC 2.6. */ + if (EXACT_POWER_OF_2_OR_ZERO_P (d)) + { + pre_shift = floor_log2 (d); + if (rem_flag) + { + remainder = expand_binop (compute_mode, and_optab, op0, + GEN_INT (((HOST_WIDE_INT) 1 << pre_shift) - 1), + remainder, 0, OPTAB_LIB_WIDEN); + if (remainder) + return gen_lowpart (mode, remainder); + } + quotient = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_2 (pre_shift, 0), + tquotient, 0); + } + else + { + rtx t1, t2, t3, t4; + + mh = choose_multiplier (d, size, size - 1, + &ml, &post_shift, &lgup); + if (mh) + abort (); + + t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_2 (size - 1, 0), NULL_RTX, 0); + t2 = expand_binop (compute_mode, xor_optab, op0, t1, + NULL_RTX, 0, OPTAB_WIDEN); + extra_cost = (shift_cost[post_shift] + + shift_cost[size - 1] + 2 * add_cost); + t3 = expand_mult_highpart (compute_mode, t2, ml, + NULL_RTX, 1, + max_cost - extra_cost); + if (t3 != 0) + { + t4 = expand_shift (RSHIFT_EXPR, compute_mode, t3, + build_int_2 (post_shift, 0), + NULL_RTX, 1); + quotient = expand_binop (compute_mode, xor_optab, + t4, t1, tquotient, 0, + OPTAB_WIDEN); + } + } + } + else + { + rtx nsign, t1, t2, t3, t4; + t1 = force_operand (gen_rtx (PLUS, compute_mode, + op0, constm1_rtx), NULL_RTX); + t2 = expand_binop (compute_mode, ior_optab, op0, t1, NULL_RTX, + 0, OPTAB_WIDEN); + nsign = expand_shift (RSHIFT_EXPR, compute_mode, t2, + build_int_2 (size - 1, 0), NULL_RTX, 0); + t3 = force_operand (gen_rtx (MINUS, compute_mode, t1, nsign), + NULL_RTX); + t4 = expand_divmod (0, TRUNC_DIV_EXPR, compute_mode, t3, op1, + NULL_RTX, 0); + if (t4) + { + rtx t5; + t5 = expand_unop (compute_mode, one_cmpl_optab, nsign, + NULL_RTX, 0); + quotient = force_operand (gen_rtx (PLUS, compute_mode, + t4, t5), + tquotient); + } + } + } + + if (quotient != 0) + break; + delete_insns_since (last); + + /* Try using an instruction that produces both the quotient and + remainder, using truncation. We can easily compensate the quotient + or remainder to get floor rounding, once we have the remainder. + Notice that we compute also the final remainder value here, + and return the result right away. */ + if (target == 0) + target = gen_reg_rtx (compute_mode); + + if (rem_flag) + { + remainder + = GET_CODE (target) == REG ? target : gen_reg_rtx (compute_mode); + quotient = gen_reg_rtx (compute_mode); + } + else + { + quotient + = GET_CODE (target) == REG ? target : gen_reg_rtx (compute_mode); + remainder = gen_reg_rtx (compute_mode); + } + + if (expand_twoval_binop (sdivmod_optab, op0, op1, + quotient, remainder, 0)) + { + /* This could be computed with a branch-less sequence. + Save that for later. */ + rtx tem; + rtx label = gen_label_rtx (); + emit_cmp_insn (remainder, const0_rtx, EQ, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_beq (label)); + tem = expand_binop (compute_mode, xor_optab, op0, op1, + NULL_RTX, 0, OPTAB_WIDEN); + emit_cmp_insn (tem, const0_rtx, GE, NULL_RTX, compute_mode, 0, 0); + emit_jump_insn (gen_bge (label)); + expand_dec (quotient, const1_rtx); + expand_inc (remainder, op1); + emit_label (label); + return gen_lowpart (mode, rem_flag ? remainder : quotient); + } + + /* No luck with division elimination or divmod. Have to do it + by conditionally adjusting op0 *and* the result. */ + { + rtx label1, label2, label3, label4, label5; + rtx adjusted_op0; + rtx tem; + + quotient = gen_reg_rtx (compute_mode); + adjusted_op0 = copy_to_mode_reg (compute_mode, op0); + label1 = gen_label_rtx (); + label2 = gen_label_rtx (); + label3 = gen_label_rtx (); + label4 = gen_label_rtx (); + label5 = gen_label_rtx (); + emit_cmp_insn (op1, const0_rtx, LT, NULL_RTX, compute_mode, 0, 0); + emit_jump_insn (gen_blt (label2)); + emit_cmp_insn (adjusted_op0, const0_rtx, LT, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_blt (label1)); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + emit_jump_insn (gen_jump (label5)); + emit_barrier (); + emit_label (label1); + expand_inc (adjusted_op0, const1_rtx); + emit_jump_insn (gen_jump (label4)); + emit_barrier (); + emit_label (label2); + emit_cmp_insn (adjusted_op0, const0_rtx, GT, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_bgt (label3)); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + emit_jump_insn (gen_jump (label5)); + emit_barrier (); + emit_label (label3); + expand_dec (adjusted_op0, const1_rtx); + emit_label (label4); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + expand_dec (quotient, const1_rtx); + emit_label (label5); + } + break; + + case CEIL_DIV_EXPR: + case CEIL_MOD_EXPR: + if (unsignedp) + { + if (op1_is_constant && EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1))) + { + rtx t1, t2, t3; + unsigned HOST_WIDE_INT d = INTVAL (op1); + t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_2 (floor_log2 (d), 0), + tquotient, 1); + t2 = expand_binop (compute_mode, and_optab, op0, + GEN_INT (d - 1), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + t3 = gen_reg_rtx (compute_mode); + t3 = emit_store_flag (t3, NE, t2, const0_rtx, + compute_mode, 1, 1); + if (t3 == 0) + { + rtx lab; + lab = gen_label_rtx (); + emit_cmp_insn (t2, const0_rtx, EQ, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_beq (lab)); + expand_inc (t1, const1_rtx); + emit_label (lab); + quotient = t1; + } + else + quotient = force_operand (gen_rtx (PLUS, compute_mode, + t1, t3), + tquotient); + break; + } + + /* Try using an instruction that produces both the quotient and + remainder, using truncation. We can easily compensate the + quotient or remainder to get ceiling rounding, once we have the + remainder. Notice that we compute also the final remainder + value here, and return the result right away. */ + if (target == 0) + target = gen_reg_rtx (compute_mode); + + if (rem_flag) + { + remainder = (GET_CODE (target) == REG + ? target : gen_reg_rtx (compute_mode)); + quotient = gen_reg_rtx (compute_mode); + } + else + { + quotient = (GET_CODE (target) == REG + ? target : gen_reg_rtx (compute_mode)); + remainder = gen_reg_rtx (compute_mode); + } + + if (expand_twoval_binop (udivmod_optab, op0, op1, quotient, + remainder, 1)) + { + /* This could be computed with a branch-less sequence. + Save that for later. */ + rtx label = gen_label_rtx (); + emit_cmp_insn (remainder, const0_rtx, EQ, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_beq (label)); + expand_inc (quotient, const1_rtx); + expand_dec (remainder, op1); + emit_label (label); + return gen_lowpart (mode, rem_flag ? remainder : quotient); + } + + /* No luck with division elimination or divmod. Have to do it + by conditionally adjusting op0 *and* the result. */ + { + rtx label1, label2; + rtx adjusted_op0, tem; + + quotient = gen_reg_rtx (compute_mode); + adjusted_op0 = copy_to_mode_reg (compute_mode, op0); + label1 = gen_label_rtx (); + label2 = gen_label_rtx (); + emit_cmp_insn (adjusted_op0, const0_rtx, NE, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_bne (label1)); + emit_move_insn (quotient, const0_rtx); + emit_jump_insn (gen_jump (label2)); + emit_barrier (); + emit_label (label1); + expand_dec (adjusted_op0, const1_rtx); + tem = expand_binop (compute_mode, udiv_optab, adjusted_op0, op1, + quotient, 1, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + expand_inc (quotient, const1_rtx); + emit_label (label2); + } + } + else /* signed */ + { + if (op1_is_constant && EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1)) + && INTVAL (op1) >= 0) + { + /* This is extremely similar to the code for the unsigned case + above. For 2.7 we should merge these variants, but for + 2.6.1 I don't want to touch the code for unsigned since that + get used in C. The signed case will only be used by other + languages (Ada). */ + + rtx t1, t2, t3; + unsigned HOST_WIDE_INT d = INTVAL (op1); + t1 = expand_shift (RSHIFT_EXPR, compute_mode, op0, + build_int_2 (floor_log2 (d), 0), + tquotient, 0); + t2 = expand_binop (compute_mode, and_optab, op0, + GEN_INT (d - 1), + NULL_RTX, 1, OPTAB_LIB_WIDEN); + t3 = gen_reg_rtx (compute_mode); + t3 = emit_store_flag (t3, NE, t2, const0_rtx, + compute_mode, 1, 1); + if (t3 == 0) + { + rtx lab; + lab = gen_label_rtx (); + emit_cmp_insn (t2, const0_rtx, EQ, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_beq (lab)); + expand_inc (t1, const1_rtx); + emit_label (lab); + quotient = t1; + } + else + quotient = force_operand (gen_rtx (PLUS, compute_mode, + t1, t3), + tquotient); + break; + } + + /* Try using an instruction that produces both the quotient and + remainder, using truncation. We can easily compensate the + quotient or remainder to get ceiling rounding, once we have the + remainder. Notice that we compute also the final remainder + value here, and return the result right away. */ + if (target == 0) + target = gen_reg_rtx (compute_mode); + if (rem_flag) + { + remainder= (GET_CODE (target) == REG + ? target : gen_reg_rtx (compute_mode)); + quotient = gen_reg_rtx (compute_mode); + } + else + { + quotient = (GET_CODE (target) == REG + ? target : gen_reg_rtx (compute_mode)); + remainder = gen_reg_rtx (compute_mode); + } + + if (expand_twoval_binop (sdivmod_optab, op0, op1, quotient, + remainder, 0)) + { + /* This could be computed with a branch-less sequence. + Save that for later. */ + rtx tem; + rtx label = gen_label_rtx (); + emit_cmp_insn (remainder, const0_rtx, EQ, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_beq (label)); + tem = expand_binop (compute_mode, xor_optab, op0, op1, + NULL_RTX, 0, OPTAB_WIDEN); + emit_cmp_insn (tem, const0_rtx, LT, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_blt (label)); + expand_inc (quotient, const1_rtx); + expand_dec (remainder, op1); + emit_label (label); + return gen_lowpart (mode, rem_flag ? remainder : quotient); + } + + /* No luck with division elimination or divmod. Have to do it + by conditionally adjusting op0 *and* the result. */ + { + rtx label1, label2, label3, label4, label5; + rtx adjusted_op0; + rtx tem; + + quotient = gen_reg_rtx (compute_mode); + adjusted_op0 = copy_to_mode_reg (compute_mode, op0); + label1 = gen_label_rtx (); + label2 = gen_label_rtx (); + label3 = gen_label_rtx (); + label4 = gen_label_rtx (); + label5 = gen_label_rtx (); + emit_cmp_insn (op1, const0_rtx, LT, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_blt (label2)); + emit_cmp_insn (adjusted_op0, const0_rtx, GT, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_bgt (label1)); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + emit_jump_insn (gen_jump (label5)); + emit_barrier (); + emit_label (label1); + expand_dec (adjusted_op0, const1_rtx); + emit_jump_insn (gen_jump (label4)); + emit_barrier (); + emit_label (label2); + emit_cmp_insn (adjusted_op0, const0_rtx, LT, NULL_RTX, + compute_mode, 0, 0); + emit_jump_insn (gen_blt (label3)); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + emit_jump_insn (gen_jump (label5)); + emit_barrier (); + emit_label (label3); + expand_inc (adjusted_op0, const1_rtx); + emit_label (label4); + tem = expand_binop (compute_mode, sdiv_optab, adjusted_op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + if (tem != quotient) + emit_move_insn (quotient, tem); + expand_inc (quotient, const1_rtx); + emit_label (label5); + } + } + break; + + case EXACT_DIV_EXPR: + if (op1_is_constant && HOST_BITS_PER_WIDE_INT >= size) + { + HOST_WIDE_INT d = INTVAL (op1); + unsigned HOST_WIDE_INT ml; + int post_shift; + rtx t1; + + post_shift = floor_log2 (d & -d); + ml = invert_mod2n (d >> post_shift, size); + t1 = expand_mult (compute_mode, op0, GEN_INT (ml), NULL_RTX, + unsignedp); + quotient = expand_shift (RSHIFT_EXPR, compute_mode, t1, + build_int_2 (post_shift, 0), + NULL_RTX, unsignedp); + + insn = get_last_insn (); + REG_NOTES (insn) + = gen_rtx (EXPR_LIST, REG_EQUAL, + gen_rtx (unsignedp ? UDIV : DIV, compute_mode, + op0, op1), + REG_NOTES (insn)); + } + break; + + case ROUND_DIV_EXPR: + case ROUND_MOD_EXPR: + if (unsignedp) + { + rtx tem; + rtx label; + label = gen_label_rtx (); + quotient = gen_reg_rtx (compute_mode); + remainder = gen_reg_rtx (compute_mode); + if (expand_twoval_binop (udivmod_optab, op0, op1, quotient, remainder, 1) == 0) + { + rtx tem; + quotient = expand_binop (compute_mode, udiv_optab, op0, op1, + quotient, 1, OPTAB_LIB_WIDEN); + tem = expand_mult (compute_mode, quotient, op1, NULL_RTX, 1); + remainder = expand_binop (compute_mode, sub_optab, op0, tem, + remainder, 1, OPTAB_LIB_WIDEN); + } + tem = plus_constant (op1, -1); + tem = expand_shift (RSHIFT_EXPR, compute_mode, tem, + build_int_2 (1, 0), NULL_RTX, 1); + emit_cmp_insn (remainder, tem, LEU, NULL_RTX, compute_mode, 0, 0); + emit_jump_insn (gen_bleu (label)); + expand_inc (quotient, const1_rtx); + expand_dec (remainder, op1); + emit_label (label); + } + else + { + rtx abs_rem, abs_op1, tem, mask; + rtx label; + label = gen_label_rtx (); + quotient = gen_reg_rtx (compute_mode); + remainder = gen_reg_rtx (compute_mode); + if (expand_twoval_binop (sdivmod_optab, op0, op1, quotient, remainder, 0) == 0) + { + rtx tem; + quotient = expand_binop (compute_mode, sdiv_optab, op0, op1, + quotient, 0, OPTAB_LIB_WIDEN); + tem = expand_mult (compute_mode, quotient, op1, NULL_RTX, 0); + remainder = expand_binop (compute_mode, sub_optab, op0, tem, + remainder, 0, OPTAB_LIB_WIDEN); + } + abs_rem = expand_abs (compute_mode, remainder, NULL_RTX, 0, 0); + abs_op1 = expand_abs (compute_mode, op1, NULL_RTX, 0, 0); + tem = expand_shift (LSHIFT_EXPR, compute_mode, abs_rem, + build_int_2 (1, 0), NULL_RTX, 1); + emit_cmp_insn (tem, abs_op1, LTU, NULL_RTX, compute_mode, 0, 0); + emit_jump_insn (gen_bltu (label)); + tem = expand_binop (compute_mode, xor_optab, op0, op1, + NULL_RTX, 0, OPTAB_WIDEN); + mask = expand_shift (RSHIFT_EXPR, compute_mode, tem, + build_int_2 (size - 1, 0), NULL_RTX, 0); + tem = expand_binop (compute_mode, xor_optab, mask, const1_rtx, + NULL_RTX, 0, OPTAB_WIDEN); + tem = expand_binop (compute_mode, sub_optab, tem, mask, + NULL_RTX, 0, OPTAB_WIDEN); + expand_inc (quotient, tem); + tem = expand_binop (compute_mode, xor_optab, mask, op1, + NULL_RTX, 0, OPTAB_WIDEN); + tem = expand_binop (compute_mode, sub_optab, tem, mask, + NULL_RTX, 0, OPTAB_WIDEN); + expand_dec (remainder, tem); + emit_label (label); + } + return gen_lowpart (mode, rem_flag ? remainder : quotient); + } + + if (quotient == 0) + { + if (rem_flag) + { + /* Try to produce the remainder directly without a library call. */ + remainder = sign_expand_binop (compute_mode, umod_optab, smod_optab, + op0, op1, target, + unsignedp, OPTAB_WIDEN); + if (remainder == 0) + { + /* No luck there. Can we do remainder and divide at once + without a library call? */ + remainder = gen_reg_rtx (compute_mode); + if (! expand_twoval_binop ((unsignedp + ? udivmod_optab + : sdivmod_optab), + op0, op1, + NULL_RTX, remainder, unsignedp)) + remainder = 0; + } + + if (remainder) + return gen_lowpart (mode, remainder); + } + + /* Produce the quotient. */ + /* Try a quotient insn, but not a library call. */ + quotient = sign_expand_binop (compute_mode, udiv_optab, sdiv_optab, + op0, op1, rem_flag ? NULL_RTX : target, + unsignedp, OPTAB_WIDEN); + if (quotient == 0) + { + /* No luck there. Try a quotient-and-remainder insn, + keeping the quotient alone. */ + quotient = gen_reg_rtx (compute_mode); + if (! expand_twoval_binop (unsignedp ? udivmod_optab : sdivmod_optab, + op0, op1, + quotient, NULL_RTX, unsignedp)) + { + quotient = 0; + if (! rem_flag) + /* Still no luck. If we are not computing the remainder, + use a library call for the quotient. */ + quotient = sign_expand_binop (compute_mode, + udiv_optab, sdiv_optab, + op0, op1, target, + unsignedp, OPTAB_LIB_WIDEN); + } + } + } + + if (rem_flag) + { + if (quotient == 0) + /* No divide instruction either. Use library for remainder. */ + remainder = sign_expand_binop (compute_mode, umod_optab, smod_optab, + op0, op1, target, + unsignedp, OPTAB_LIB_WIDEN); + else + { + /* We divided. Now finish doing X - Y * (X / Y). */ + remainder = expand_mult (compute_mode, quotient, op1, + NULL_RTX, unsignedp); + remainder = expand_binop (compute_mode, sub_optab, op0, + remainder, target, unsignedp, + OPTAB_LIB_WIDEN); + } + } + + return gen_lowpart (mode, rem_flag ? remainder : quotient); +} + +/* Return a tree node with data type TYPE, describing the value of X. + Usually this is an RTL_EXPR, if there is no obvious better choice. + X may be an expression, however we only support those expressions + generated by loop.c. */ + +tree +make_tree (type, x) + tree type; + rtx x; +{ + tree t; + + switch (GET_CODE (x)) + { + case CONST_INT: + t = build_int_2 (INTVAL (x), + TREE_UNSIGNED (type) || INTVAL (x) >= 0 ? 0 : -1); + TREE_TYPE (t) = type; + return t; + + case CONST_DOUBLE: + if (GET_MODE (x) == VOIDmode) + { + t = build_int_2 (CONST_DOUBLE_LOW (x), CONST_DOUBLE_HIGH (x)); + TREE_TYPE (t) = type; + } + else + { + REAL_VALUE_TYPE d; + + REAL_VALUE_FROM_CONST_DOUBLE (d, x); + t = build_real (type, d); + } + + return t; + + case PLUS: + return fold (build (PLUS_EXPR, type, make_tree (type, XEXP (x, 0)), + make_tree (type, XEXP (x, 1)))); + + case MINUS: + return fold (build (MINUS_EXPR, type, make_tree (type, XEXP (x, 0)), + make_tree (type, XEXP (x, 1)))); + + case NEG: + return fold (build1 (NEGATE_EXPR, type, make_tree (type, XEXP (x, 0)))); + + case MULT: + return fold (build (MULT_EXPR, type, make_tree (type, XEXP (x, 0)), + make_tree (type, XEXP (x, 1)))); + + case ASHIFT: + return fold (build (LSHIFT_EXPR, type, make_tree (type, XEXP (x, 0)), + make_tree (type, XEXP (x, 1)))); + + case LSHIFTRT: + return fold (convert (type, + build (RSHIFT_EXPR, unsigned_type (type), + make_tree (unsigned_type (type), + XEXP (x, 0)), + make_tree (type, XEXP (x, 1))))); + + case ASHIFTRT: + return fold (convert (type, + build (RSHIFT_EXPR, signed_type (type), + make_tree (signed_type (type), XEXP (x, 0)), + make_tree (type, XEXP (x, 1))))); + + case DIV: + if (TREE_CODE (type) != REAL_TYPE) + t = signed_type (type); + else + t = type; + + return fold (convert (type, + build (TRUNC_DIV_EXPR, t, + make_tree (t, XEXP (x, 0)), + make_tree (t, XEXP (x, 1))))); + case UDIV: + t = unsigned_type (type); + return fold (convert (type, + build (TRUNC_DIV_EXPR, t, + make_tree (t, XEXP (x, 0)), + make_tree (t, XEXP (x, 1))))); + default: + t = make_node (RTL_EXPR); + TREE_TYPE (t) = type; + RTL_EXPR_RTL (t) = x; + /* There are no insns to be output + when this rtl_expr is used. */ + RTL_EXPR_SEQUENCE (t) = 0; + return t; + } +} + +/* Return an rtx representing the value of X * MULT + ADD. + TARGET is a suggestion for where to store the result (an rtx). + MODE is the machine mode for the computation. + X and MULT must have mode MODE. ADD may have a different mode. + So can X (defaults to same as MODE). + UNSIGNEDP is non-zero to do unsigned multiplication. + This may emit insns. */ + +rtx +expand_mult_add (x, target, mult, add, mode, unsignedp) + rtx x, target, mult, add; + enum machine_mode mode; + int unsignedp; +{ + tree type = type_for_mode (mode, unsignedp); + tree add_type = (GET_MODE (add) == VOIDmode + ? type : type_for_mode (GET_MODE (add), unsignedp)); + tree result = fold (build (PLUS_EXPR, type, + fold (build (MULT_EXPR, type, + make_tree (type, x), + make_tree (type, mult))), + make_tree (add_type, add))); + + return expand_expr (result, target, VOIDmode, 0); +} + +/* Compute the logical-and of OP0 and OP1, storing it in TARGET + and returning TARGET. + + If TARGET is 0, a pseudo-register or constant is returned. */ + +rtx +expand_and (op0, op1, target) + rtx op0, op1, target; +{ + enum machine_mode mode = VOIDmode; + rtx tem; + + if (GET_MODE (op0) != VOIDmode) + mode = GET_MODE (op0); + else if (GET_MODE (op1) != VOIDmode) + mode = GET_MODE (op1); + + if (mode != VOIDmode) + tem = expand_binop (mode, and_optab, op0, op1, target, 0, OPTAB_LIB_WIDEN); + else if (GET_CODE (op0) == CONST_INT && GET_CODE (op1) == CONST_INT) + tem = GEN_INT (INTVAL (op0) & INTVAL (op1)); + else + abort (); + + if (target == 0) + target = tem; + else if (tem != target) + emit_move_insn (target, tem); + return target; +} + +/* Emit a store-flags instruction for comparison CODE on OP0 and OP1 + and storing in TARGET. Normally return TARGET. + Return 0 if that cannot be done. + + MODE is the mode to use for OP0 and OP1 should they be CONST_INTs. If + it is VOIDmode, they cannot both be CONST_INT. + + UNSIGNEDP is for the case where we have to widen the operands + to perform the operation. It says to use zero-extension. + + NORMALIZEP is 1 if we should convert the result to be either zero + or one one. Normalize is -1 if we should convert the result to be + either zero or -1. If NORMALIZEP is zero, the result will be left + "raw" out of the scc insn. */ + +rtx +emit_store_flag (target, code, op0, op1, mode, unsignedp, normalizep) + rtx target; + enum rtx_code code; + rtx op0, op1; + enum machine_mode mode; + int unsignedp; + int normalizep; +{ + rtx subtarget; + enum insn_code icode; + enum machine_mode compare_mode; + enum machine_mode target_mode = GET_MODE (target); + rtx tem; + rtx last = get_last_insn (); + rtx pattern, comparison; + + /* If one operand is constant, make it the second one. Only do this + if the other operand is not constant as well. */ + + if ((CONSTANT_P (op0) && ! CONSTANT_P (op1)) + || (GET_CODE (op0) == CONST_INT && GET_CODE (op1) != CONST_INT)) + { + tem = op0; + op0 = op1; + op1 = tem; + code = swap_condition (code); + } + + if (mode == VOIDmode) + mode = GET_MODE (op0); + + /* For some comparisons with 1 and -1, we can convert this to + comparisons with zero. This will often produce more opportunities for + store-flag insns. */ + + switch (code) + { + case LT: + if (op1 == const1_rtx) + op1 = const0_rtx, code = LE; + break; + case LE: + if (op1 == constm1_rtx) + op1 = const0_rtx, code = LT; + break; + case GE: + if (op1 == const1_rtx) + op1 = const0_rtx, code = GT; + break; + case GT: + if (op1 == constm1_rtx) + op1 = const0_rtx, code = GE; + break; + case GEU: + if (op1 == const1_rtx) + op1 = const0_rtx, code = NE; + break; + case LTU: + if (op1 == const1_rtx) + op1 = const0_rtx, code = EQ; + break; + } + + /* From now on, we won't change CODE, so set ICODE now. */ + icode = setcc_gen_code[(int) code]; + + /* If this is A < 0 or A >= 0, we can do this by taking the ones + complement of A (for GE) and shifting the sign bit to the low bit. */ + if (op1 == const0_rtx && (code == LT || code == GE) + && GET_MODE_CLASS (mode) == MODE_INT + && (normalizep || STORE_FLAG_VALUE == 1 + || (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT + && (STORE_FLAG_VALUE + == (HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1))))) + { + subtarget = target; + + /* If the result is to be wider than OP0, it is best to convert it + first. If it is to be narrower, it is *incorrect* to convert it + first. */ + if (GET_MODE_SIZE (target_mode) > GET_MODE_SIZE (mode)) + { + op0 = protect_from_queue (op0, 0); + op0 = convert_modes (target_mode, mode, op0, 0); + mode = target_mode; + } + + if (target_mode != mode) + subtarget = 0; + + if (code == GE) + op0 = expand_unop (mode, one_cmpl_optab, op0, subtarget, 0); + + if (normalizep || STORE_FLAG_VALUE == 1) + /* If we are supposed to produce a 0/1 value, we want to do + a logical shift from the sign bit to the low-order bit; for + a -1/0 value, we do an arithmetic shift. */ + op0 = expand_shift (RSHIFT_EXPR, mode, op0, + size_int (GET_MODE_BITSIZE (mode) - 1), + subtarget, normalizep != -1); + + if (mode != target_mode) + op0 = convert_modes (target_mode, mode, op0, 0); + + return op0; + } + + if (icode != CODE_FOR_nothing) + { + /* We think we may be able to do this with a scc insn. Emit the + comparison and then the scc insn. + + compare_from_rtx may call emit_queue, which would be deleted below + if the scc insn fails. So call it ourselves before setting LAST. */ + + emit_queue (); + last = get_last_insn (); + + comparison + = compare_from_rtx (op0, op1, code, unsignedp, mode, NULL_RTX, 0); + if (GET_CODE (comparison) == CONST_INT) + return (comparison == const0_rtx ? const0_rtx + : normalizep == 1 ? const1_rtx + : normalizep == -1 ? constm1_rtx + : const_true_rtx); + + /* If the code of COMPARISON doesn't match CODE, something is + wrong; we can no longer be sure that we have the operation. + We could handle this case, but it should not happen. */ + + if (GET_CODE (comparison) != code) + abort (); + + /* Get a reference to the target in the proper mode for this insn. */ + compare_mode = insn_operand_mode[(int) icode][0]; + subtarget = target; + if (preserve_subexpressions_p () + || ! (*insn_operand_predicate[(int) icode][0]) (subtarget, compare_mode)) + subtarget = gen_reg_rtx (compare_mode); + + pattern = GEN_FCN (icode) (subtarget); + if (pattern) + { + emit_insn (pattern); + + /* If we are converting to a wider mode, first convert to + TARGET_MODE, then normalize. This produces better combining + opportunities on machines that have a SIGN_EXTRACT when we are + testing a single bit. This mostly benefits the 68k. + + If STORE_FLAG_VALUE does not have the sign bit set when + interpreted in COMPARE_MODE, we can do this conversion as + unsigned, which is usually more efficient. */ + if (GET_MODE_SIZE (target_mode) > GET_MODE_SIZE (compare_mode)) + { + convert_move (target, subtarget, + (GET_MODE_BITSIZE (compare_mode) + <= HOST_BITS_PER_WIDE_INT) + && 0 == (STORE_FLAG_VALUE + & ((HOST_WIDE_INT) 1 + << (GET_MODE_BITSIZE (compare_mode) -1)))); + op0 = target; + compare_mode = target_mode; + } + else + op0 = subtarget; + + /* If we want to keep subexpressions around, don't reuse our + last target. */ + + if (preserve_subexpressions_p ()) + subtarget = 0; + + /* Now normalize to the proper value in COMPARE_MODE. Sometimes + we don't have to do anything. */ + if (normalizep == 0 || normalizep == STORE_FLAG_VALUE) + ; + else if (normalizep == - STORE_FLAG_VALUE) + op0 = expand_unop (compare_mode, neg_optab, op0, subtarget, 0); + + /* We don't want to use STORE_FLAG_VALUE < 0 below since this + makes it hard to use a value of just the sign bit due to + ANSI integer constant typing rules. */ + else if (GET_MODE_BITSIZE (compare_mode) <= HOST_BITS_PER_WIDE_INT + && (STORE_FLAG_VALUE + & ((HOST_WIDE_INT) 1 + << (GET_MODE_BITSIZE (compare_mode) - 1)))) + op0 = expand_shift (RSHIFT_EXPR, compare_mode, op0, + size_int (GET_MODE_BITSIZE (compare_mode) - 1), + subtarget, normalizep == 1); + else if (STORE_FLAG_VALUE & 1) + { + op0 = expand_and (op0, const1_rtx, subtarget); + if (normalizep == -1) + op0 = expand_unop (compare_mode, neg_optab, op0, op0, 0); + } + else + abort (); + + /* If we were converting to a smaller mode, do the + conversion now. */ + if (target_mode != compare_mode) + { + convert_move (target, op0, 0); + return target; + } + else + return op0; + } + } + + delete_insns_since (last); + + /* If expensive optimizations, use different pseudo registers for each + insn, instead of reusing the same pseudo. This leads to better CSE, + but slows down the compiler, since there are more pseudos */ + subtarget = (!flag_expensive_optimizations + && (target_mode == mode)) ? target : NULL_RTX; + + /* If we reached here, we can't do this with a scc insn. However, there + are some comparisons that can be done directly. For example, if + this is an equality comparison of integers, we can try to exclusive-or + (or subtract) the two operands and use a recursive call to try the + comparison with zero. Don't do any of these cases if branches are + very cheap. */ + + if (BRANCH_COST > 0 + && GET_MODE_CLASS (mode) == MODE_INT && (code == EQ || code == NE) + && op1 != const0_rtx) + { + tem = expand_binop (mode, xor_optab, op0, op1, subtarget, 1, + OPTAB_WIDEN); + + if (tem == 0) + tem = expand_binop (mode, sub_optab, op0, op1, subtarget, 1, + OPTAB_WIDEN); + if (tem != 0) + tem = emit_store_flag (target, code, tem, const0_rtx, + mode, unsignedp, normalizep); + if (tem == 0) + delete_insns_since (last); + return tem; + } + + /* Some other cases we can do are EQ, NE, LE, and GT comparisons with + the constant zero. Reject all other comparisons at this point. Only + do LE and GT if branches are expensive since they are expensive on + 2-operand machines. */ + + if (BRANCH_COST == 0 + || GET_MODE_CLASS (mode) != MODE_INT || op1 != const0_rtx + || (code != EQ && code != NE + && (BRANCH_COST <= 1 || (code != LE && code != GT)))) + return 0; + + /* See what we need to return. We can only return a 1, -1, or the + sign bit. */ + + if (normalizep == 0) + { + if (STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1) + normalizep = STORE_FLAG_VALUE; + + else if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT + && (STORE_FLAG_VALUE + == (HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1))) + ; + else + return 0; + } + + /* Try to put the result of the comparison in the sign bit. Assume we can't + do the necessary operation below. */ + + tem = 0; + + /* To see if A <= 0, compute (A | (A - 1)). A <= 0 iff that result has + the sign bit set. */ + + if (code == LE) + { + /* This is destructive, so SUBTARGET can't be OP0. */ + if (rtx_equal_p (subtarget, op0)) + subtarget = 0; + + tem = expand_binop (mode, sub_optab, op0, const1_rtx, subtarget, 0, + OPTAB_WIDEN); + if (tem) + tem = expand_binop (mode, ior_optab, op0, tem, subtarget, 0, + OPTAB_WIDEN); + } + + /* To see if A > 0, compute (((signed) A) << BITS) - A, where BITS is the + number of bits in the mode of OP0, minus one. */ + + if (code == GT) + { + if (rtx_equal_p (subtarget, op0)) + subtarget = 0; + + tem = expand_shift (RSHIFT_EXPR, mode, op0, + size_int (GET_MODE_BITSIZE (mode) - 1), + subtarget, 0); + tem = expand_binop (mode, sub_optab, tem, op0, subtarget, 0, + OPTAB_WIDEN); + } + + if (code == EQ || code == NE) + { + /* For EQ or NE, one way to do the comparison is to apply an operation + that converts the operand into a positive number if it is non-zero + or zero if it was originally zero. Then, for EQ, we subtract 1 and + for NE we negate. This puts the result in the sign bit. Then we + normalize with a shift, if needed. + + Two operations that can do the above actions are ABS and FFS, so try + them. If that doesn't work, and MODE is smaller than a full word, + we can use zero-extension to the wider mode (an unsigned conversion) + as the operation. */ + + if (abs_optab->handlers[(int) mode].insn_code != CODE_FOR_nothing) + tem = expand_unop (mode, abs_optab, op0, subtarget, 1); + else if (ffs_optab->handlers[(int) mode].insn_code != CODE_FOR_nothing) + tem = expand_unop (mode, ffs_optab, op0, subtarget, 1); + else if (GET_MODE_SIZE (mode) < UNITS_PER_WORD) + { + op0 = protect_from_queue (op0, 0); + tem = convert_modes (word_mode, mode, op0, 1); + mode = word_mode; + } + + if (tem != 0) + { + if (code == EQ) + tem = expand_binop (mode, sub_optab, tem, const1_rtx, subtarget, + 0, OPTAB_WIDEN); + else + tem = expand_unop (mode, neg_optab, tem, subtarget, 0); + } + + /* If we couldn't do it that way, for NE we can "or" the two's complement + of the value with itself. For EQ, we take the one's complement of + that "or", which is an extra insn, so we only handle EQ if branches + are expensive. */ + + if (tem == 0 && (code == NE || BRANCH_COST > 1)) + { + if (rtx_equal_p (subtarget, op0)) + subtarget = 0; + + tem = expand_unop (mode, neg_optab, op0, subtarget, 0); + tem = expand_binop (mode, ior_optab, tem, op0, subtarget, 0, + OPTAB_WIDEN); + + if (tem && code == EQ) + tem = expand_unop (mode, one_cmpl_optab, tem, subtarget, 0); + } + } + + if (tem && normalizep) + tem = expand_shift (RSHIFT_EXPR, mode, tem, + size_int (GET_MODE_BITSIZE (mode) - 1), + subtarget, normalizep == 1); + + if (tem) + { + if (GET_MODE (tem) != target_mode) + { + convert_move (target, tem, 0); + tem = target; + } + else if (!subtarget) + { + emit_move_insn (target, tem); + tem = target; + } + } + else + delete_insns_since (last); + + return tem; +} |
