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builtins.c (expand_builtin_strlen): Be prepared for strlensi to fail.

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* builtins.c (expand_builtin_strlen): Be prepared for strlensi
        to fail.  Don't pre-expand the source operand.

From-SVN: r32429
This commit is contained in:
Richard Henderson 2000-03-08 11:21:13 -08:00 committed by Richard Henderson
parent c5aa680d46
commit dd05e4fae9
2 changed files with 37 additions and 22 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2000-03-08 Richard Henderson <rth@cygnus.com>
* builtins.c (expand_builtin_strlen): Be prepared for strlensi
to fail. Don't pre-expand the source operand.
* i386.md (strlensi): Initialize eoschar and align before use.
2000-03-08 Jason Merrill <jason@casey.cygnus.com>
* expr.c (expand_expr, case ARRAY_REF): Still check for missing

52
gcc/builtins.c
View File

@ -1334,13 +1334,14 @@ expand_builtin_strlen (exp, target, mode)
return 0;
else
{
rtx pat;
tree src = TREE_VALUE (arglist);
tree len = c_strlen (src);
int align
= get_pointer_alignment (src, BIGGEST_ALIGNMENT) / BITS_PER_UNIT;
rtx result, src_rtx, char_rtx;
rtx result, src_reg, char_rtx, before_strlen;
enum machine_mode insn_mode = value_mode, char_mode;
enum insn_code icode = CODE_FOR_nothing;
@ -1352,8 +1353,7 @@ expand_builtin_strlen (exp, target, mode)
if (align == 0)
return 0;
/* Call a function if we can't compute strlen in the right mode. */
/* Bail out if we can't compute strlen in the right mode. */
while (insn_mode != VOIDmode)
{
icode = strlen_optab->handlers[(int) insn_mode].insn_code;
@ -1373,21 +1373,19 @@ expand_builtin_strlen (exp, target, mode)
&& REGNO (result) >= FIRST_PSEUDO_REGISTER))
result = gen_reg_rtx (insn_mode);
/* Make sure the operands are acceptable to the predicates. */
/* Make a place to hold the source address. We will not expand
the actual source until we are sure that the expansion will
not fail -- there are trees that cannot be expanded twice. */
src_reg = gen_reg_rtx (Pmode);
if (! (*insn_data[(int)icode].operand[0].predicate) (result, insn_mode))
result = gen_reg_rtx (insn_mode);
src_rtx = memory_address (BLKmode,
expand_expr (src, NULL_RTX, ptr_mode,
EXPAND_NORMAL));
if (! (*insn_data[(int)icode].operand[1].predicate) (src_rtx, Pmode))
src_rtx = copy_to_mode_reg (Pmode, src_rtx);
/* Mark the beginning of the strlen sequence so we can emit the
source operand later. */
before_strlen = get_last_insn();
/* Check the string is readable and has an end. */
if (current_function_check_memory_usage)
emit_library_call (chkr_check_str_libfunc, 1, VOIDmode, 2,
src_rtx, Pmode,
src_reg, Pmode,
GEN_INT (MEMORY_USE_RO),
TYPE_MODE (integer_type_node));
@ -1396,20 +1394,30 @@ expand_builtin_strlen (exp, target, mode)
if (! (*insn_data[(int)icode].operand[2].predicate) (char_rtx, char_mode))
char_rtx = copy_to_mode_reg (char_mode, char_rtx);
emit_insn (GEN_FCN (icode) (result,
gen_rtx_MEM (BLKmode, src_rtx),
char_rtx, GEN_INT (align)));
pat = GEN_FCN (icode) (result, gen_rtx_MEM (BLKmode, src_reg),
char_rtx, GEN_INT (align));
if (! pat)
return 0;
emit_insn (pat);
/* Now that we are assured of success, expand the source. */
start_sequence ();
pat = expand_expr (src, src_reg, ptr_mode, EXPAND_SUM);
if (pat != src_reg)
emit_move_insn (src_reg, pat);
pat = gen_sequence ();
end_sequence ();
emit_insn_after (pat, before_strlen);
/* Return the value in the proper mode for this function. */
if (GET_MODE (result) == value_mode)
return result;
target = result;
else if (target != 0)
{
convert_move (target, result, 0);
return target;
}
convert_move (target, result, 0);
else
return convert_to_mode (value_mode, result, 0);
target = convert_to_mode (value_mode, result, 0);
return target;
}
}