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| author | Jakub Staszak <jstaszak@apple.com> | 2011-07-31 04:47:20 +0000 |
|---|---|---|
| committer | Jakub Staszak <jstaszak@apple.com> | 2011-07-31 04:47:20 +0000 |
| commit | a385c20d427d8ec1a91ce8bf34612bf4c87cc34f (patch) | |
| tree | fbfbbc545c33383fa4c09579850201542b4d71e8 /lib/Analysis/BranchProbabilityInfo.cpp | |
| parent | 592ad6a82facd7d7ee58c599767a1b0c85eda0c5 (diff) | |
| download | llvm-a385c20d427d8ec1a91ce8bf34612bf4c87cc34f.tar.gz llvm-a385c20d427d8ec1a91ce8bf34612bf4c87cc34f.tar.bz2 llvm-a385c20d427d8ec1a91ce8bf34612bf4c87cc34f.tar.xz | |
Do not handle case where LHS is equal to zero, because InstCombiner always moves
it to RHS anyway.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136586 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/BranchProbabilityInfo.cpp')
| -rw-r--r-- | lib/Analysis/BranchProbabilityInfo.cpp | 32 |
1 files changed, 8 insertions, 24 deletions
diff --git a/lib/Analysis/BranchProbabilityInfo.cpp b/lib/Analysis/BranchProbabilityInfo.cpp index 5a7d6bf59a..014cedc1d5 100644 --- a/lib/Analysis/BranchProbabilityInfo.cpp +++ b/lib/Analysis/BranchProbabilityInfo.cpp @@ -287,21 +287,9 @@ bool BranchProbabilityAnalysis::calcZeroHeuristics(BasicBlock *BB) { if (!CI) return false; - Value *LHS = CI->getOperand(0); Value *RHS = CI->getOperand(1); - - bool hasZero = false; - bool lhsZero = false; - if (ConstantInt *CI = dyn_cast<ConstantInt>(LHS)) { - hasZero = CI->isZero(); - lhsZero = true; - } - - if (!hasZero) - if (ConstantInt *CI = dyn_cast<ConstantInt>(RHS)) - hasZero = CI->isZero(); - - if (!hasZero) + ConstantInt *CV = dyn_cast<ConstantInt>(RHS); + if (!CV || !CV->isZero()) return false; bool isProb; @@ -321,11 +309,9 @@ bool BranchProbabilityAnalysis::calcZeroHeuristics(BasicBlock *BB) { case CmpInst::ICMP_SLT: case CmpInst::ICMP_SLE: // Less or equal to zero is not expected. - // 0 < X -> isProb = true - // 0 <= X -> isProb = true - // X < 0 -> isProb = false - // X <= 0 -> isProb = false - isProb = lhsZero; + // X < 0 -> Unlikely + // X <= 0 -> Unlikely + isProb = false; break; case CmpInst::ICMP_UGT: @@ -333,11 +319,9 @@ bool BranchProbabilityAnalysis::calcZeroHeuristics(BasicBlock *BB) { case CmpInst::ICMP_SGT: case CmpInst::ICMP_SGE: // Greater or equal to zero is expected. - // 0 > X -> isProb = false - // 0 >= X -> isProb = false - // X > 0 -> isProb = true - // X >= 0 -> isProb = true - isProb = !lhsZero; + // X > 0 -> Likely + // X >= 0 -> Likely + isProb = true; break; default: |