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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 | 05fc35e275529eddb6c73bed7595bd7cec93f27a (patch) | |
| tree | fc85d3171c18033d0c423f5fca9bc627faa4ef05 /llvm/lib/CodeGen/RegAllocLinearScan.cpp | |
| parent | 4a34e61e53b4a87365b0352256735e104b84d055 (diff) | |
| download | bcm5719-llvm-05fc35e275529eddb6c73bed7595bd7cec93f27a.tar.gz bcm5719-llvm-05fc35e275529eddb6c73bed7595bd7cec93f27a.zip | |
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
llvm-svn: 131172
Diffstat (limited to 'llvm/lib/CodeGen/RegAllocLinearScan.cpp')
0 files changed, 0 insertions, 0 deletions
