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| author | Dale Johannesen <dalej@apple.com> | 2007-06-08 01:08:52 +0000 |
|---|---|---|
| committer | Dale Johannesen <dalej@apple.com> | 2007-06-08 01:08:52 +0000 |
| commit | 86798e5e1146a09079ff6632d07baa0c41001c86 (patch) | |
| tree | 4b43c64dfabe6ef0c7971180a9806df66f0aa08f /llvm/lib | |
| parent | be80240b29d53fde95838f8478314a90dff3561f (diff) | |
| download | bcm5719-llvm-86798e5e1146a09079ff6632d07baa0c41001c86.tar.gz bcm5719-llvm-86798e5e1146a09079ff6632d07baa0c41001c86.zip | |
Make throttle a hidden parameter, per review.
llvm-svn: 37511
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/CodeGen/BranchFolding.cpp | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp index 1125511a846..71fac0b8eb7 100644 --- a/llvm/lib/CodeGen/BranchFolding.cpp +++ b/llvm/lib/CodeGen/BranchFolding.cpp @@ -38,6 +38,12 @@ STATISTIC(NumTailMerge , "Number of block tails merged"); static cl::opt<cl::boolOrDefault> FlagEnableTailMerge("enable-tail-merge", cl::init(cl::BOU_UNSET), cl::Hidden); namespace { + // Throttle for huge numbers of predecessors (compile speed problems) + cl::opt<unsigned> + TailMergeThreshold("tail-merge-threshold", + cl::desc("Max number of predecessors to consider tail merging"), + cl::init(100), cl::Hidden); + struct BranchFolder : public MachineFunctionPass { static char ID; BranchFolder(bool defaultEnableTailMerge) : @@ -564,9 +570,6 @@ bool BranchFolder::TryMergeBlocks(MachineBasicBlock *SuccBB, return MadeChange; } -// Throttle for huge numbers of predecessors (compile speed problems) -#define THRESHOLD 100 - bool BranchFolder::TailMergeBlocks(MachineFunction &MF) { if (!EnableTailMerge) return false; @@ -580,7 +583,7 @@ bool BranchFolder::TailMergeBlocks(MachineFunction &MF) { MergePotentials.push_back(std::make_pair(HashEndOfMBB(I, 2U), I)); } // See if we can do any tail merging on those. - if (MergePotentials.size() < THRESHOLD) + if (MergePotentials.size() < TailMergeThreshold) MadeChange |= TryMergeBlocks(NULL, NULL); // Look at blocks (IBB) with multiple predecessors (PBB). @@ -603,11 +606,13 @@ bool BranchFolder::TailMergeBlocks(MachineFunction &MF) { // transformations.) for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) { - if (!I->succ_empty() && I->pred_size() >= 2 && I->pred_size() < THRESHOLD) { + if (!I->succ_empty() && I->pred_size() >= 2 && + I->pred_size() < TailMergeThreshold) { MachineBasicBlock *IBB = I; MachineBasicBlock *PredBB = prior(I); MergePotentials.clear(); - for (MachineBasicBlock::pred_iterator P = I->pred_begin(), E2 = I->pred_end(); + for (MachineBasicBlock::pred_iterator P = I->pred_begin(), + E2 = I->pred_end(); P != E2; ++P) { MachineBasicBlock* PBB = *P; // Skip blocks that loop to themselves, can't tail merge these. |
