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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-03-29 17:22:39 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2012-03-29 17:22:39 +0000 |
| commit | 41e2073f623a08504e2e1e5a9fc5c9f22a03eb83 (patch) | |
| tree | c4f05adc3565dc1ccd4bdfd913e4a9b091e23fdb /lib/Transforms/Scalar/GlobalMerge.cpp | |
| parent | 73478404af7f6b6e64bdda5920ebaede6a4e7a14 (diff) | |
Don't PRE compares.
CodeGenPrepare sinks compare instructions down to their uses to prevent
live flags and predicate registers across basic blocks.
PRE of a compare instruction prevents that, forcing the i1 compare
result into a general purpose register. That is usually more expensive
than the redundant compare PRE was trying to eliminate in the first
place.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153657 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/Scalar/GlobalMerge.cpp')
0 files changed, 0 insertions, 0 deletions