teach instsimplify to transform (X / Y) * Y to X
when the div is an exact udiv.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124994 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index 220868f..7bb8f69 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -735,9 +735,11 @@
// (X / Y) * Y -> X if the division is exact.
Value *X = 0, *Y = 0;
if ((match(Op0, m_SDiv(m_Value(X), m_Value(Y))) && Y == Op1) || // (X / Y) * Y
- (match(Op1, m_SDiv(m_Value(X), m_Value(Y))) && Y == Op0)) { // Y * (X / Y)
- BinaryOperator *SDiv = cast<BinaryOperator>(Y == Op1 ? Op0 : Op1);
- if (SDiv->isExact())
+ (match(Op0, m_UDiv(m_Value(X), m_Value(Y))) && Y == Op1) ||
+ (match(Op1, m_SDiv(m_Value(X), m_Value(Y))) && Y == Op0) || // Y * (X / Y)
+ (match(Op1, m_UDiv(m_Value(X), m_Value(Y))) && Y == Op0)) {
+ BinaryOperator *Div = cast<BinaryOperator>(Y == Op1 ? Op0 : Op1);
+ if (Div->isExact())
return X;
}