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| author | Jakub Jelinek <jakub@redhat.com> | 2021-04-27 14:47:54 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2021-04-27 14:47:54 +0200 |
| commit | 75f8900159133ce069ef1d2edf3b67c7bc82e305 (patch) | |
| tree | 9e267659619ba04d9dbbc58c462abe08fec770a8 /gcc/gimple-match-head.c | |
| parent | 3dcd1334b4f522352b80814513fdca902fc2a207 (diff) | |
| download | gcc-75f8900159133ce069ef1d2edf3b67c7bc82e305.zip gcc-75f8900159133ce069ef1d2edf3b67c7bc82e305.tar.gz gcc-75f8900159133ce069ef1d2edf3b67c7bc82e305.tar.bz2 | |
match.pd: Add some __builtin_ctz (x) cmp cst simplifications [PR95527]
This patch adds some ctz simplifications (e.g. ctz (x) >= 3 can be done by
testing if the low 3 bits are zero, etc.).
In addition, I've noticed that in the CLZ case, the
#ifdef CLZ_DEFINED_VALUE_AT_ZERO don't really work as intended, they
are evaluated during genmatch and the macro is not defined then
(but, because of the missing tm.h includes it isn't defined in
gimple-match.c or generic-match.c either). And when tm.h is included,
defaults.h is included which defines a fallback version of that macro.
For GCC 12, I wonder if it wouldn't be better to say in addition to __builtin_c[lt]z*
is always UB at zero that it would be undefined for .C[LT]Z ifn too if it
has just one operand and use a second operand to be the constant we expect
at zero.
2021-04-27 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/95527
* generic-match-head.c: Include tm.h.
* gimple-match-head.c: Include tm.h.
* match.pd (CLZ == INTEGER_CST): Don't use
#ifdef CLZ_DEFINED_VALUE_AT_ZERO, only test CLZ_DEFINED_VALUE_AT_ZERO
if clz == CFN_CLZ. Add missing val declaration.
(CTZ cmp CST): New simplifications.
* gcc.dg/tree-ssa/pr95527-2.c: New test.
Diffstat (limited to 'gcc/gimple-match-head.c')
| -rw-r--r-- | gcc/gimple-match-head.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/gcc/gimple-match-head.c b/gcc/gimple-match-head.c index 84fbaef..b084a3157 100644 --- a/gcc/gimple-match-head.c +++ b/gcc/gimple-match-head.c @@ -43,6 +43,7 @@ along with GCC; see the file COPYING3. If not see #include "optabs-tree.h" #include "tree-eh.h" #include "dbgcnt.h" +#include "tm.h" /* Forward declarations of the private auto-generated matchers. They expect valueized operands in canonical order and do not |