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| author | Cameron Zwarich <zwarich@apple.com> | 2011-01-17 01:08:59 +0000 |
|---|---|---|
| committer | Cameron Zwarich <zwarich@apple.com> | 2011-01-17 01:08:59 +0000 |
| commit | 814cd9233e8543904f6835e8f7badf894f2370ed (patch) | |
| tree | 7618a232f9ca48fb5c4193e4855dcba27b0c584f /llvm/lib/Transforms/Utils/Mem2Reg.cpp | |
| parent | 7d92ee38523f21d41593e953034a9069dfdda70d (diff) | |
| download | llvm-814cd9233e8543904f6835e8f7badf894f2370ed.zip llvm-814cd9233e8543904f6835e8f7badf894f2370ed.tar.gz llvm-814cd9233e8543904f6835e8f7badf894f2370ed.tar.bz2 | |
Eliminate the use of dominance frontiers in PromoteMemToReg. In addition to
eliminating a potentially quadratic data structure, this also gives a 17%
speedup when running -scalarrepl on test-suite + SPEC2000 + SPEC2006. My initial
experiment gave a greater speedup around 25%, but I moved the dominator tree
level computation from dominator tree construction to PromoteMemToReg.
Since this approach to computing IDFs has a much lower overhead than the old
code using precomputed DFs, it is worth looking at using this new code for the
second scalarrepl pass as well.
llvm-svn: 123609
Diffstat (limited to 'llvm/lib/Transforms/Utils/Mem2Reg.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Utils/Mem2Reg.cpp | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/llvm/lib/Transforms/Utils/Mem2Reg.cpp b/llvm/lib/Transforms/Utils/Mem2Reg.cpp index 2b1364c..ea2f8fc 100644 --- a/llvm/lib/Transforms/Utils/Mem2Reg.cpp +++ b/llvm/lib/Transforms/Utils/Mem2Reg.cpp @@ -40,7 +40,6 @@ namespace { // virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequired<DominatorTree>(); - AU.addRequired<DominanceFrontier>(); AU.setPreservesCFG(); // This is a cluster of orthogonal Transforms AU.addPreserved<UnifyFunctionExitNodes>(); @@ -54,7 +53,6 @@ char PromotePass::ID = 0; INITIALIZE_PASS_BEGIN(PromotePass, "mem2reg", "Promote Memory to Register", false, false) INITIALIZE_PASS_DEPENDENCY(DominatorTree) -INITIALIZE_PASS_DEPENDENCY(DominanceFrontier) INITIALIZE_PASS_END(PromotePass, "mem2reg", "Promote Memory to Register", false, false) @@ -66,7 +64,6 @@ bool PromotePass::runOnFunction(Function &F) { bool Changed = false; DominatorTree &DT = getAnalysis<DominatorTree>(); - DominanceFrontier &DF = getAnalysis<DominanceFrontier>(); while (1) { Allocas.clear(); @@ -80,7 +77,7 @@ bool PromotePass::runOnFunction(Function &F) { if (Allocas.empty()) break; - PromoteMemToReg(Allocas, DT, DF); + PromoteMemToReg(Allocas, DT); NumPromoted += Allocas.size(); Changed = true; } |