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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2010-11-17 19:11:46 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2010-11-17 19:11:46 +0000 |
| commit | 1951a5b721187ab85db0b2db55ae39eec3733c20 (patch) | |
| tree | 8a1c6d468ac64fe45ffd85783f8b576d0a850209 | |
| parent | 2b749870d0488c3b049edf5d0c8875f56f5b1bed (diff) | |
InstCombine: Add a missing irem identity (X % X -> 0).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119538 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 4 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/rem.ll | 5 |
2 files changed, 9 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index c2ae4cc637..1433f7bbc9 100644 --- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -551,6 +551,10 @@ Instruction *InstCombiner::commonIRemTransforms(BinaryOperator &I) { if (Instruction *common = commonRemTransforms(I)) return common; + // X % X == 0 + if (Op0 == Op1) + return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType())); + // 0 % X == 0 for integer, we don't need to preserve faults! if (Constant *LHS = dyn_cast<Constant>(Op0)) if (LHS->isNullValue()) diff --git a/test/Transforms/InstCombine/rem.ll b/test/Transforms/InstCombine/rem.ll index bac248e58d..b421b7c0e8 100644 --- a/test/Transforms/InstCombine/rem.ll +++ b/test/Transforms/InstCombine/rem.ll @@ -81,3 +81,8 @@ define i32 @test12(i32 %i) { %tmp.5 = srem i32 %tmp.1, 2 ret i32 %tmp.5 } + +define i32 @test13(i32 %i) { + %x = srem i32 %i, %i + ret i32 %x +} |