diff options
| author | Manman Ren <mren@apple.com> | 2012-06-07 22:39:10 +0000 |
|---|---|---|
| committer | Manman Ren <mren@apple.com> | 2012-06-07 22:39:10 +0000 |
| commit | 9236362a64ce1609222512fe3f17eeb886a3ddea (patch) | |
| tree | cb91606183c09759e1c7b415ea72c4665025cc7c /cmake | |
| parent | fa371eaff3c06b4d5a5ff5706a552f519b469756 (diff) | |
| download | llvm-9236362a64ce1609222512fe3f17eeb886a3ddea.tar.gz llvm-9236362a64ce1609222512fe3f17eeb886a3ddea.tar.bz2 llvm-9236362a64ce1609222512fe3f17eeb886a3ddea.tar.xz | |
X86: optimize generated code for integer ABS
This patch will generate the following for integer ABS:
movl %edi, %eax
negl %eax
cmovll %edi, %eax
INSTEAD OF
movl %edi, %ecx
sarl $31, %ecx
leal (%rdi,%rcx), %eax
xorl %ecx, %eax
There exists a target-independent DAG combine for integer ABS, which converts
integer ABS to sar+add+xor. For X86, we match this pattern back to neg+cmov.
This is implemented in PerformXorCombine.
rdar://10695237
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158175 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'cmake')
0 files changed, 0 insertions, 0 deletions