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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 | f7073d144562eaa7dfd45533b6e682c496769aab (patch) | |
| tree | d5f89899636e8160d12209b8aaf21ec05f8c94b1 /llvm/lib/CodeGen | |
| parent | 3295a99fe9eaf3133719bc1c2aa32f81bab731cd (diff) | |
| download | bcm5719-llvm-f7073d144562eaa7dfd45533b6e682c496769aab.tar.gz bcm5719-llvm-f7073d144562eaa7dfd45533b6e682c496769aab.zip | |
Update comments.
llvm-svn: 124843
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/TailDuplication.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/TailDuplication.cpp b/llvm/lib/CodeGen/TailDuplication.cpp index 83706deb3f7..04d3d311b41 100644 --- a/llvm/lib/CodeGen/TailDuplication.cpp +++ b/llvm/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; |
