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| author | Evan Cheng <evan.cheng@apple.com> | 2011-05-11 01:03:01 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2011-05-11 01:03:01 +0000 |
| commit | 7e20a574eb3f4fc3840a0490c814443d756e2e0e (patch) | |
| tree | 7e148f185b14e932bf5f84bb0e8e6714aa5f53e1 /include | |
| parent | b38fe4b52de05a35c0693f4fd117f908a2abadb7 (diff) | |
| download | external_llvm-7e20a574eb3f4fc3840a0490c814443d756e2e0e.zip external_llvm-7e20a574eb3f4fc3840a0490c814443d756e2e0e.tar.gz external_llvm-7e20a574eb3f4fc3840a0490c814443d756e2e0e.tar.bz2 | |
Add a late optimization to BranchFolding that hoist common instruction sequences
at the start of basic blocks to their common predecessor. It's actually quite
common (e.g. about 50 times in JM/lencod) and has shown to be a nice code size
benefit. e.g.
pushq %rax
testl %edi, %edi
jne LBB0_2
## BB#1:
xorb %al, %al
popq %rdx
ret
LBB0_2:
xorb %al, %al
callq _foo
popq %rdx
ret
=>
pushq %rax
xorb %al, %al
testl %edi, %edi
je LBB0_2
## BB#1:
callq _foo
LBB0_2:
popq %rdx
ret
rdar://9145558
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131172 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions