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| author | Evan Cheng <evan.cheng@apple.com> | 2011-02-04 01:10:12 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2011-02-04 01:10:12 +0000 |
| commit | c8b90e22a8f2987126a7e2e841adc8db9776521c (patch) | |
| tree | 6be63f4ae4072083ca6b1e969e67d0133da0275e /lib/CodeGen | |
| parent | 9ecd1e71973f555cab00ee862b6f509d0126025a (diff) | |
| download | external_llvm-c8b90e22a8f2987126a7e2e841adc8db9776521c.zip external_llvm-c8b90e22a8f2987126a7e2e841adc8db9776521c.tar.gz external_llvm-c8b90e22a8f2987126a7e2e841adc8db9776521c.tar.bz2 | |
Update comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124843 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen')
| -rw-r--r-- | lib/CodeGen/TailDuplication.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/lib/CodeGen/TailDuplication.cpp b/lib/CodeGen/TailDuplication.cpp index 83706de..04d3d31 100644 --- a/lib/CodeGen/TailDuplication.cpp +++ b/lib/CodeGen/TailDuplication.cpp @@ -504,8 +504,9 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF, if (!I->isPHI() && !I->isDebugValue()) InstrCount += 1; } - // Heuristically, don't tail-duplicate calls if it would expand code size, - // as it's less likely to be worth the extra cost. + // Don't tail-duplicate calls before register allocation. Calls presents a + // barrier to register allocation so duplicating them may end up increasing + // spills. if (InstrCount > 1 && (PreRegAlloc && HasCall)) return false; |