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Diffstat (limited to 'gnu/usr.bin/cc/cc1plus/expr.c')
| -rw-r--r-- | gnu/usr.bin/cc/cc1plus/expr.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/gnu/usr.bin/cc/cc1plus/expr.c b/gnu/usr.bin/cc/cc1plus/expr.c new file mode 100644 index 0000000..c2213d5 --- /dev/null +++ b/gnu/usr.bin/cc/cc1plus/expr.c @@ -0,0 +1,275 @@ +/* Convert language-specific tree expression to rtl instructions, + for GNU compiler. + Copyright (C) 1988, 1992, 1993 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. */ + + +#include "config.h" +#include "rtl.h" +#include "tree.h" +#include "flags.h" +#include "expr.h" +#include "cp-tree.h" + +#undef NULL +#define NULL 0 + +/* Hook used by expand_expr to expand language-specific tree codes. */ + +rtx +cplus_expand_expr (exp, target, tmode, modifier) + tree exp; + rtx target; + enum machine_mode tmode; + enum expand_modifier modifier; +{ + tree type = TREE_TYPE (exp); + register enum machine_mode mode = TYPE_MODE (type); + register enum tree_code code = TREE_CODE (exp); + rtx original_target = target; + int ignore = target == const0_rtx; + + if (ignore) + target = 0, original_target = 0; + + /* No sense saving up arithmetic to be done + if it's all in the wrong mode to form part of an address. + And force_operand won't know whether to sign-extend or zero-extend. */ + + if (mode != Pmode && modifier == EXPAND_SUM) + modifier = EXPAND_NORMAL; + + switch (code) + { + case NEW_EXPR: + { + /* Something needs to be initialized, but we didn't know + where that thing was when building the tree. For example, + it could be the return value of a function, or a parameter + to a function which lays down in the stack, or a temporary + variable which must be passed by reference. + + Cleanups are handled in a language-specific way: they + might be run by the called function (true in GNU C++ + for parameters with cleanups), or they might be + run by the caller, after the call (true in GNU C++ + for other cleanup needs). */ + + tree func = TREE_OPERAND (exp, 0); + tree args = TREE_OPERAND (exp, 1); + tree type = TREE_TYPE (exp), slot; + tree fn_type = TREE_TYPE (TREE_TYPE (func)); + tree return_type = TREE_TYPE (fn_type); + tree call_exp; + rtx call_target, return_target; + int pcc_struct_return = 0; + + /* The expression `init' wants to initialize what + `target' represents. SLOT holds the slot for TARGET. */ + slot = TREE_OPERAND (exp, 2); + + if (target == 0) + { + /* Should always be called with a target in BLKmode case. */ + my_friendly_assert (mode != BLKmode, 205); + my_friendly_assert (DECL_RTL (slot) != 0, 206); + + target = gen_reg_rtx (mode); + } + + /* The target the initializer will initialize (CALL_TARGET) + must now be directed to initialize the target we are + supposed to initialize (TARGET). The semantics for + choosing what CALL_TARGET is is language-specific, + as is building the call which will perform the + initialization. It is left here to show the choices that + exist for C++. */ + + if (TREE_CODE (func) == ADDR_EXPR + && TREE_CODE (TREE_OPERAND (func, 0)) == FUNCTION_DECL + && DECL_CONSTRUCTOR_P (TREE_OPERAND (func, 0))) + { + type = TYPE_POINTER_TO (type); + /* Don't clobber a value that might be part of a default + parameter value. */ + if (TREE_PERMANENT (args)) + args = tree_cons (0, build1 (ADDR_EXPR, type, slot), + TREE_CHAIN (args)); + else + TREE_VALUE (args) = build1 (ADDR_EXPR, type, slot); + call_target = 0; + } + else if (TREE_CODE (return_type) == REFERENCE_TYPE) + { + type = return_type; + call_target = 0; + } + else + { +#ifdef PCC_STATIC_STRUCT_RETURN + pcc_struct_return = 1; + call_target = 0; +#else + call_target = target; +#endif + } + if (call_target) + { + preserve_temp_slots (call_target); + + /* Make this a valid memory address now. The code below assumes + that it can compare rtx and make assumptions based on the + result. The assumptions are true only if the address was + valid to begin with. */ + call_target = validize_mem (call_target); + } + + preserve_temp_slots (DECL_RTL (slot)); + call_exp = build (CALL_EXPR, type, func, args, 0); + TREE_SIDE_EFFECTS (call_exp) = 1; + return_target = expand_expr (call_exp, call_target, mode, 0); + free_temp_slots (); + if (call_target == 0) + { + if (pcc_struct_return) + { + tree init = build (RTL_EXPR, type, 0, return_target); + TREE_ADDRESSABLE (init) = 1; + expand_aggr_init (slot, init, 0); + if (TYPE_NEEDS_DESTRUCTOR (type)) + { + init = build (RTL_EXPR, build_reference_type (type), 0, + XEXP (return_target, 0)); + init = maybe_build_cleanup (convert_from_reference (init)); + if (init != NULL_TREE) + expand_expr (init, 0, 0, 0); + } + call_target = return_target = DECL_RTL (slot); + } + else + call_target = return_target; + } + + if (call_target != return_target) + { + my_friendly_assert (! TYPE_NEEDS_CONSTRUCTING (type), 317); + if (GET_MODE (return_target) == BLKmode) + emit_block_move (call_target, return_target, expr_size (exp), + TYPE_ALIGN (type) / BITS_PER_UNIT); + else + emit_move_insn (call_target, return_target); + } + + if (TREE_CODE (return_type) == REFERENCE_TYPE) + { + tree init; + + if (GET_CODE (call_target) == REG + && REGNO (call_target) < FIRST_PSEUDO_REGISTER) + my_friendly_abort (39); + + type = TREE_TYPE (exp); + + init = build (RTL_EXPR, return_type, 0, call_target); + /* We got back a reference to the type we want. Now initialize + target with that. */ + expand_aggr_init (slot, init, 0); + } + + if (DECL_RTL (slot) != target) + emit_move_insn (DECL_RTL (slot), target); + return DECL_RTL (slot); + } + + case OFFSET_REF: + { +#if 1 + return expand_expr (default_conversion (resolve_offset_ref (exp)), + target, tmode, EXPAND_NORMAL); +#else + /* This is old crusty code, and does not handle all that the + resolve_offset_ref function does. (mrs) */ + tree base = build_unary_op (ADDR_EXPR, TREE_OPERAND (exp, 0), 0); + tree offset = build_unary_op (ADDR_EXPR, TREE_OPERAND (exp, 1), 0); + return expand_expr (build (PLUS_EXPR, TREE_TYPE (exp), base, offset), + target, tmode, EXPAND_NORMAL); +#endif + } + + case THUNK_DECL: + return DECL_RTL (exp); + + case THROW_EXPR: + expand_throw (TREE_OPERAND (exp, 0)); + return NULL; + + default: + break; + } + my_friendly_abort (40); + /* NOTREACHED */ + return NULL; +} + +void +init_cplus_expand () +{ + lang_expand_expr = cplus_expand_expr; +} + +/* If DECL had its rtl moved from where callers expect it + to be, fix it up. RESULT is the nominal rtl for the RESULT_DECL, + which may be a pseudo instead of a hard register. */ + +void +fixup_result_decl (decl, result) + tree decl; + rtx result; +{ + if (REG_P (result)) + { + if (REGNO (result) >= FIRST_PSEUDO_REGISTER) + { + rtx real_decl_result; + +#ifdef FUNCTION_OUTGOING_VALUE + real_decl_result + = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl), current_function_decl); +#else + real_decl_result + = FUNCTION_VALUE (TREE_TYPE (decl), current_function_decl); +#endif + REG_FUNCTION_VALUE_P (real_decl_result) = 1; + result = real_decl_result; + } + emit_move_insn (result, DECL_RTL (decl)); + emit_insn (gen_rtx (USE, VOIDmode, result)); + } +} + +/* Return nonzero iff DECL is memory-based. The DECL_RTL of + certain const variables might be a CONST_INT, or a REG + in some cases. We cannot use `memory_operand' as a test + here because on most RISC machines, a variable's address + is not, by itself, a legitimate address. */ +int +decl_in_memory_p (decl) + tree decl; +{ + return DECL_RTL (decl) != 0 && GET_CODE (DECL_RTL (decl)) == MEM; +} |
