diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp | 3 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopStrengthReduce/2011-07-20-DoubleIV.ll | 24 |
2 files changed, 27 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp index e90b5bcacd9..4598df0c428 100644 --- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -3740,6 +3740,9 @@ LSRInstance::LSRInstance(const TargetLowering *tli, Loop *l, Pass *P) OptimizeShadowIV(); OptimizeLoopTermCond(); + // If loop preparation eliminates all interesting IV users, bail. + if (IU.empty()) return; + // Start collecting data and preparing for the solver. CollectInterestingTypesAndFactors(); CollectFixupsAndInitialFormulae(); diff --git a/llvm/test/Transforms/LoopStrengthReduce/2011-07-20-DoubleIV.ll b/llvm/test/Transforms/LoopStrengthReduce/2011-07-20-DoubleIV.ll new file mode 100644 index 00000000000..3ceeeb658d1 --- /dev/null +++ b/llvm/test/Transforms/LoopStrengthReduce/2011-07-20-DoubleIV.ll @@ -0,0 +1,24 @@ +; RUN: opt < %s -loop-reduce -S | FileCheck %s +; +; Test LSR's OptimizeShadowIV. Handle a floating-point IV with a +; nonzero initial value. +; rdar://9786536 + +; First, make sure LSR doesn't crash on an empty IVUsers list. +; CHECK: @dummyIV +; CHECK-NOT: phi +; CHECK-NOT: sitofp +; CHECK: br +define void @dummyIV() nounwind { +entry: + br label %loop + +loop: + %i.01 = phi i32 [ -39, %entry ], [ %inc, %loop ] + %conv7 = sitofp i32 %i.01 to double + %inc = add nsw i32 %i.01, 1 + br i1 undef, label %loop, label %for.end + +for.end: + unreachable +} |
