diff options
Diffstat (limited to 'lib/CodeGen/BranchFolding.cpp')
| -rw-r--r-- | lib/CodeGen/BranchFolding.cpp | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp index 66c5aa5ff7..11777d5ea1 100644 --- a/lib/CodeGen/BranchFolding.cpp +++ b/lib/CodeGen/BranchFolding.cpp @@ -50,8 +50,9 @@ TailMergeThreshold("tail-merge-threshold", char BranchFolderPass::ID = 0; -FunctionPass *llvm::createBranchFoldingPass(bool DefaultEnableTailMerge) { - return new BranchFolderPass(DefaultEnableTailMerge); +FunctionPass *llvm::createBranchFoldingPass(bool DefaultEnableTailMerge, + CodeGenOpt::Level OptLevel) { + return new BranchFolderPass(DefaultEnableTailMerge, OptLevel); } bool BranchFolderPass::runOnMachineFunction(MachineFunction &MF) { @@ -63,7 +64,8 @@ bool BranchFolderPass::runOnMachineFunction(MachineFunction &MF) { -BranchFolder::BranchFolder(bool defaultEnableTailMerge) { +BranchFolder::BranchFolder(bool defaultEnableTailMerge, CodeGenOpt::Level OL) { + OptLevel = OL; switch (FlagEnableTailMerge) { case cl::BOU_UNSET: EnableTailMerge = defaultEnableTailMerge; break; case cl::BOU_TRUE: EnableTailMerge = true; break; @@ -470,7 +472,8 @@ unsigned BranchFolder::ComputeSameTails(unsigned CurHash, I->second, TrialBBI1, TrialBBI2); // If we will have to split a block, there should be at least - // minCommonTailLength instructions in common; if not, at worst + // minCommonTailLength instructions in common; if not, and if we are not + // optimizing for performance at the expense of code size, at worst // we will be replacing a fallthrough into the common tail with a // branch, which at worst breaks even with falling through into // the duplicated common tail, so 1 instruction in common is enough. @@ -478,7 +481,8 @@ unsigned BranchFolder::ComputeSameTails(unsigned CurHash, // tail if there is one. // (Empty blocks will get forwarded and need not be considered.) if (CommonTailLen >= minCommonTailLength || - (CommonTailLen > 0 && + (OptLevel != CodeGenOpt::Aggressive && + CommonTailLen > 0 && (TrialBBI1==CurMPIter->second->begin() || TrialBBI2==I->second->begin()))) { if (CommonTailLen > maxCommonTailLength) { |