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| author | Alexandre Oliva <aoliva@redhat.com> | 2005-02-03 09:09:42 +0000 |
|---|---|---|
| committer | Alexandre Oliva <aoliva@gcc.gnu.org> | 2005-02-03 09:09:42 +0000 |
| commit | aa2d0bc31c2dac0ecde72d92d7d419be5a8f21b3 (patch) | |
| tree | 2670e900e343f8a26a16c91b8c9efacb96709618 /gcc/combine.c | |
| parent | f1a3e333f0f5c214ed5801ed3546d0f8caf9f5fc (diff) | |
| download | gcc-aa2d0bc31c2dac0ecde72d92d7d419be5a8f21b3.zip gcc-aa2d0bc31c2dac0ecde72d92d7d419be5a8f21b3.tar.gz gcc-aa2d0bc31c2dac0ecde72d92d7d419be5a8f21b3.tar.bz2 | |
combine.c (simplify_comparison, [...]): Do not drop the extend if we'd have to add a paradoxical subreg later.
gcc/ChangeLog:
* combine.c (simplify_comparison, case SIGN_EXTEND, ZERO_EXTEND):
Do not drop the extend if we'd have to add a paradoxical subreg
later. Include optabs.h and insn-codes.h.
* Makefile.in (combine.o): Depend on $(OPTABS_H).
gcc/testsuite/ChangeLog:
* gcc.c-torture/execute/20050203-1.c: New.
From-SVN: r94655
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 6badd28..ae773b9 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -90,6 +90,8 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA #include "real.h" #include "toplev.h" #include "target.h" +#include "optabs.h" +#include "insn-codes.h" #include "rtlhooks-def.h" /* Include output.h for dump_file. */ #include "output.h" @@ -10054,16 +10056,22 @@ simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1) break; case SIGN_EXTEND: - /* Can simplify (compare (zero/sign_extend FOO) CONST) - to (compare FOO CONST) if CONST fits in FOO's mode and we - are either testing inequality or have an unsigned comparison - with ZERO_EXTEND or a signed comparison with SIGN_EXTEND. */ - if (! unsigned_comparison_p - && (GET_MODE_BITSIZE (GET_MODE (XEXP (op0, 0))) - <= HOST_BITS_PER_WIDE_INT) + /* Can simplify (compare (zero/sign_extend FOO) CONST) to + (compare FOO CONST) if CONST fits in FOO's mode and we + are either testing inequality or have an unsigned + comparison with ZERO_EXTEND or a signed comparison with + SIGN_EXTEND. But don't do it if we don't have a compare + insn of the given mode, since we'd have to revert it + later on, and then we wouldn't know whether to sign- or + zero-extend. */ + mode = GET_MODE (XEXP (op0, 0)); + if (mode != VOIDmode && GET_MODE_CLASS (mode) == MODE_INT + && ! unsigned_comparison_p + && (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT) && ((unsigned HOST_WIDE_INT) const_op - < (((unsigned HOST_WIDE_INT) 1 - << (GET_MODE_BITSIZE (GET_MODE (XEXP (op0, 0))) - 1))))) + < (((unsigned HOST_WIDE_INT) 1 + << (GET_MODE_BITSIZE (mode) - 1)))) + && cmp_optab->handlers[(int) mode].insn_code != CODE_FOR_nothing) { op0 = XEXP (op0, 0); continue; @@ -10139,11 +10147,12 @@ simplify_comparison (enum rtx_code code, rtx *pop0, rtx *pop1) /* ... fall through ... */ case ZERO_EXTEND: - if ((unsigned_comparison_p || equality_comparison_p) - && (GET_MODE_BITSIZE (GET_MODE (XEXP (op0, 0))) - <= HOST_BITS_PER_WIDE_INT) - && ((unsigned HOST_WIDE_INT) const_op - < GET_MODE_MASK (GET_MODE (XEXP (op0, 0))))) + mode = GET_MODE (XEXP (op0, 0)); + if (mode != VOIDmode && GET_MODE_CLASS (mode) == MODE_INT + && (unsigned_comparison_p || equality_comparison_p) + && (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT) + && ((unsigned HOST_WIDE_INT) const_op < GET_MODE_MASK (mode)) + && cmp_optab->handlers[(int) mode].insn_code != CODE_FOR_nothing) { op0 = XEXP (op0, 0); continue; |