Fix LSR's OptimizeSMax to ignore max operators with more than 2 operands,

which it isn't prepared to handle.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73787 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 03966672d623aa9b48a9e58528210ce463cdff2a..dac734029b4aa0921dc5e11d0691329808b6dde9 100644 (file)
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -2116,6 +2116,11 @@ ICmpInst *LoopStrengthReduce::OptimizeSMax(Loop *L, ICmpInst *Cond,
   const SCEVSMaxExpr *SMax = dyn_cast<SCEVSMaxExpr>(IterationCount);
   if (!SMax || SMax != SE->getSCEV(Sel)) return Cond;
 
+  // Two handle a max with more than two operands, this optimization would
+  // require additional checking and setup.
+  if (SMax->getNumOperands() != 2)
+    return Cond;
+
   SCEVHandle SMaxLHS = SMax->getOperand(0);
   SCEVHandle SMaxRHS = SMax->getOperand(1);
   if (!SMaxLHS || SMaxLHS != One) return Cond;