diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 4 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/div.ll | 14 |
2 files changed, 16 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 2f4b1926d8..0f9df27fa4 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -3012,6 +3012,10 @@ Instruction *InstCombiner::commonDivTransforms(BinaryOperator &I) { Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) { Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1); + // (sdiv X, X) --> 1 (udiv X, X) --> 1 + if (Op0 == Op1) + return ReplaceInstUsesWith(I, ConstantInt::get(I.getType(), 1)); + if (Instruction *Common = commonDivTransforms(I)) return Common; diff --git a/test/Transforms/InstCombine/div.ll b/test/Transforms/InstCombine/div.ll index b21d39b7a5..ea6ea6323c 100644 --- a/test/Transforms/InstCombine/div.ll +++ b/test/Transforms/InstCombine/div.ll @@ -1,8 +1,6 @@ ; This test makes sure that div instructions are properly eliminated. -; ; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep div -; END. define i32 @test1(i32 %A) { %B = sdiv i32 %A, 1 ; <i32> [#uses=1] @@ -72,3 +70,15 @@ define i32 @test11(i32 %X, i1 %C) { %B = udiv i32 %X, %A ; <i32> [#uses=1] ret i32 %B } + +; PR2328 +define i32 @test12(i32 %x) nounwind { + %tmp3 = udiv i32 %x, %x ; 1 + ret i32 %tmp3 +} + +define i32 @test13(i32 %x) nounwind { + %tmp3 = sdiv i32 %x, %x ; 1 + ret i32 %tmp3 +} + |