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Diffstat (limited to 'gnu/usr.bin/cc/include/bi-run.h')
| -rw-r--r-- | gnu/usr.bin/cc/include/bi-run.h | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/gnu/usr.bin/cc/include/bi-run.h b/gnu/usr.bin/cc/include/bi-run.h new file mode 100644 index 0000000..669f2ab --- /dev/null +++ b/gnu/usr.bin/cc/include/bi-run.h @@ -0,0 +1,165 @@ +/* Definitions for Bytecode Interpreter. + Copyright (C) 1993, 1994 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, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#define MAXLITERALS 5 + +struct arityvec +{ + char ninputs; + char noutputs; + char nliterals; + char literals[MAXLITERALS]; +}; + +struct argtype +{ + int modealign; /* Argument mode:alignment */ + int size; /* Argument size, in bytes */ +}; + +struct callinfo +{ + int nargs; /* Number of arguments in call */ + struct argtype retvaltype; /* Type of return value */ + struct argtype argtypes[1]; /* Argument types */ +}; + +/* Structure describing a bytecode function. If this changes, we also + need to change expand_function_end () in bc-trans.c */ +struct bytecode +{ + int stacksize; /* Depth required of evaluation stack. */ + int localsize; /* Size in bytes of local variables. */ + unsigned char *pc0; /* Initial program counter. */ + void **ptrlit; /* Vector of (relocatable) pointer literals. */ + struct callinfo *callinfo; /* Vector of procedure call type info. */ +}; + + +#define INTERP_BPC 8 /* Bits per char */ +#define INTERP_BPI \ + (sizeof (int) * INTERP_BPC) /* Bits per int */ + + +#ifndef min +#define min(L, R) ((L) < (R) ? (L) : (R)) +#endif + + +/* bit field operations. */ + +/* Low (high) mask: int with low (high) N bits set */ + +#define LM(N) ((1 << (N)) - 1) +#define HM(N) ((~LM (INTERP_BPI - (N)))) + + +/* Sign-extend SIZE low bits of VALUE to integer (typeof VALUE) + Signed bitfields are loaded from memory by the sxloadBI instruction, + which first retrieves the bitfield with XFIELD and then sign extends + it to an SItype. */ + +#define EXTEND(SIZE, VALUE) \ + ({ SUtype value = (SUtype) (VALUE); \ + (value & (1 << ((SIZE) - 1)) ? value | ~LM (SIZE) : value); }) + + +/* Given OFFSET:SIZE for a bitfield, calculate: + + [1] BYTE_OFFSET = the byte offset of the bit field. + [2] BIT_OFFSET = the bit offset of the bit field (less than INTERP_BPC). + [3] NBYTES = the number of integral bytes in the bit field. + [4] TRAILING_BITS= the number of trailing bits (less than INTERP_BPC). + + + , , , , , (memory bytes) + ---------------- (bitfield) + | | || | | (divisions) + ^ ^ ^ ^ + | | | |__ [4] (bits) + | | |_________ [3] (bytes) + | |_________________ [2] (bits) + |___________________________ [1] (bytes) + + + The above applies to BYTE_LOW_ENDIAN machines. In BYTE_BIG_ENDIAN machines, the + bit numbering is reversed (i.e. bit 0 is the sign bit). + + (Alright, so I drew this to keep my tongue in cheek while writing the code below, + not because I'm into ASCII art.) */ + + +#define BI_PARAMS(OFFSET, SIZE, BYTE_OFFSET, BIT_OFFSET, NBYTES, TRAILING_BITS) \ + { BYTE_OFFSET = (OFFSET) / (INTERP_BPC); \ + BIT_OFFSET = (OFFSET) % (INTERP_BPC); \ + NBYTES = ((SIZE) - (INTERP_BPC - (BIT_OFFSET))) / INTERP_BPC; \ + if ((NBYTES) < 0 || ((NBYTES) > 64)) \ + NBYTES = 0; \ + if ((SIZE) + (BIT_OFFSET) <= INTERP_BPC) \ + TRAILING_BITS = 0; \ + else \ + TRAILING_BITS = ((SIZE) - (INTERP_BPC - (BIT_OFFSET))) % INTERP_BPC; } + + +/* SHIFT_IN_BITS retrieves NBITS bits from SOURCE and shifts into + DEST. The bit field starts OFFSET bits into SOURCE. + + OR_IN_BITS copies the NBITS low bits from VALUE into a the bitfield in + DEST offset by OFFSET bits. */ + + +#if BYTES_BIG_ENDIAN + +#define SHIFT_IN_BITS(DEST, SOURCE, OFFSET, NBITS) \ + (DEST = ((DEST) << (NBITS)) \ + | (LM ((NBITS)) \ + & ((SOURCE) >> (INTERP_BPC - (OFFSET) - (NBITS))))) + +#define OR_IN_BITS(DEST, VALUE, OFFSET, NBITS) \ + (DEST = ((DEST) & ~(LM ((NBITS)) << (INTERP_BPC - (OFFSET) - (NBITS)))) \ + | (((VALUE) & LM ((NBITS))) << (INTERP_BPC - (OFFSET) - (NBITS)))) + +#else + +#define SHIFT_IN_BITS(DEST, SOURCE, OFFSET, NBITS) \ + (DEST = ((DEST) << (NBITS)) \ + | (LM ((NBITS)) \ + & ((SOURCE) >> (OFFSET)))) + +#define OR_IN_BITS(DEST, VALUE, OFFSET, NBITS) \ + (DEST = ((DEST) & ~(LM ((NBITS)) << (OFFSET))) \ + | (((VALUE) & LM ((NBITS))) << (OFFSET))) + +#endif + + +/* Procedure call; arguments are a pointer to the function to be called, + a pointer to a place to store the return value, a pointer to a vector + describing the type of procedure call, and the interpreter's stack pointer, + which will point to the first of the arguments at this point. */ + +#define CALL(FUNC, CALLDESC, RETVAL, SP) __call(FUNC, CALLDESC, RETVAL, SP) + + +/* Procedure return; arguments are a pointer to the calldesc for this + function, and a pointer to the place where the value to be returned + may be found. Generally the MACHARGS above contain a machine dependent + cookie that is used to determine where to jump to. */ + +#define PROCRET(CALLDESC, RETVAL) return |
