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| author | Duncan Sands <baldrick@free.fr> | 2010-11-15 17:52:45 +0000 |
|---|---|---|
| committer | Duncan Sands <baldrick@free.fr> | 2010-11-15 17:52:45 +0000 |
| commit | 552008946530e01efdad15044e1f621883d14a3a (patch) | |
| tree | f03a042355f51a15a352a2872e313f399573f336 /lib/Analysis/InstructionSimplify.cpp | |
| parent | 503dcc982227893c532f03cbd6449e01a1739df3 (diff) | |
| download | llvm-552008946530e01efdad15044e1f621883d14a3a.tar.gz llvm-552008946530e01efdad15044e1f621883d14a3a.tar.bz2 llvm-552008946530e01efdad15044e1f621883d14a3a.tar.xz | |
Teach InstructionSimplify the trick of skipping incoming phi
values that are equal to the phi itself.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119161 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Analysis/InstructionSimplify.cpp')
| -rw-r--r-- | lib/Analysis/InstructionSimplify.cpp | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index 282e0d31be..a8288bf67a 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -142,9 +142,12 @@ static Value *ThreadBinOpOverPHI(unsigned Opcode, Value *LHS, Value *RHS, // Evaluate the BinOp on the incoming phi values. Value *CommonValue = 0; for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { + Value *Incoming = PI->getIncomingValue(i); + // If the incoming value is the phi node itself, it can be safely skipped. + if (Incoming == PI) continue; Value *V = PI == LHS ? - SimplifyBinOp(Opcode, PI->getIncomingValue(i), RHS, TD, MaxRecurse) : - SimplifyBinOp(Opcode, LHS, PI->getIncomingValue(i), TD, MaxRecurse); + SimplifyBinOp(Opcode, Incoming, RHS, TD, MaxRecurse) : + SimplifyBinOp(Opcode, LHS, Incoming, TD, MaxRecurse); // If the operation failed to simplify, or simplified to a different value // to previously, then give up. if (!V || (CommonValue && V != CommonValue)) @@ -172,8 +175,10 @@ static Value *ThreadCmpOverPHI(CmpInst::Predicate Pred, Value *LHS, Value *RHS, // Evaluate the BinOp on the incoming phi values. Value *CommonValue = 0; for (unsigned i = 0, e = PI->getNumIncomingValues(); i != e; ++i) { - Value *V = SimplifyCmpInst(Pred, PI->getIncomingValue(i), RHS, TD, - MaxRecurse); + Value *Incoming = PI->getIncomingValue(i); + // If the incoming value is the phi node itself, it can be safely skipped. + if (Incoming == PI) continue; + Value *V = SimplifyCmpInst(Pred, Incoming, RHS, TD, MaxRecurse); // If the operation failed to simplify, or simplified to a different value // to previously, then give up. if (!V || (CommonValue && V != CommonValue)) |