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| author | Jakub Jelinek <jakub@redhat.com> | 2013-05-14 10:55:34 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2013-05-14 10:55:34 +0200 |
| commit | 75776c6d256cf2db9cd470484445bff01c7e30fa (patch) | |
| tree | cf62bd2045ab3fa40d75cb48379cb1295898c3a7 /gcc/expmed.c | |
| parent | df35498ae56e297e0de7279127cab265e71fc2d2 (diff) | |
| download | gcc-75776c6d256cf2db9cd470484445bff01c7e30fa.zip gcc-75776c6d256cf2db9cd470484445bff01c7e30fa.tar.gz gcc-75776c6d256cf2db9cd470484445bff01c7e30fa.tar.bz2 | |
expmed.c (expand_shift_1): Canonicalize rotates by constant bitsize / 2 to bitsize - 1.
* expmed.c (expand_shift_1): Canonicalize rotates by
constant bitsize / 2 to bitsize - 1.
* simplify-rt.x (simplify_binary_operation_1) <case ROTATE,
case ROTATERT>: Likewise.
Revert:
2013-05-10 Jakub Jelinek <jakub@redhat.com>
* config/i386/i386.md (rotateinv): New code attr.
(*<rotate_insn><mode>3_1, *<rotate_insn>si3_1_zext,
*<rotate_insn>qi3_1_slp): Emit rorl %eax instead of
roll $31, %eax, etc.
From-SVN: r198864
Diffstat (limited to 'gcc/expmed.c')
| -rw-r--r-- | gcc/expmed.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/gcc/expmed.c b/gcc/expmed.c index 6e61e9a..c85e68c 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -2122,6 +2122,20 @@ expand_shift_1 (enum tree_code code, enum machine_mode mode, rtx shifted, op1 = SUBREG_REG (op1); } + /* Canonicalize rotates by constant amount. If op1 is bitsize / 2, + prefer left rotation, if op1 is from bitsize / 2 + 1 to + bitsize - 1, use other direction of rotate with 1 .. bitsize / 2 - 1 + amount instead. */ + if (rotate + && CONST_INT_P (op1) + && IN_RANGE (INTVAL (op1), GET_MODE_BITSIZE (mode) / 2 + left, + GET_MODE_BITSIZE (mode) - 1)) + { + op1 = GEN_INT (GET_MODE_BITSIZE (mode) - INTVAL (op1)); + left = !left; + code = left ? LROTATE_EXPR : RROTATE_EXPR; + } + if (op1 == const0_rtx) return shifted; |