Restore r181216, which was partially reverted in r182499.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186533 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index eac24c63451..c3621af638b 100644
--- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -556,6 +556,35 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
       }
     }
 
+    // B * (uitofp i1 C) -> select C, B, 0
+    if (I.hasNoNaNs() && I.hasNoInfs() && I.hasNoSignedZeros()) {
+      Value *LHS = Op0, *RHS = Op1;
+      Value *B, *C;
+      if (!match(RHS, m_UIToFp(m_Value(C))))
+        std::swap(LHS, RHS);
+
+      if (match(RHS, m_UIToFp(m_Value(C))) && C->getType()->isIntegerTy(1)) {
+        B = LHS;
+        Value *Zero = ConstantFP::getNegativeZero(B->getType());
+        return SelectInst::Create(C, B, Zero);
+      }
+    }
+
+    // A * (1 - uitofp i1 C) -> select C, 0, A
+    if (I.hasNoNaNs() && I.hasNoInfs() && I.hasNoSignedZeros()) {
+      Value *LHS = Op0, *RHS = Op1;
+      Value *A, *C;
+      if (!match(RHS, m_FSub(m_FPOne(), m_UIToFp(m_Value(C)))))
+        std::swap(LHS, RHS);
+
+      if (match(RHS, m_FSub(m_FPOne(), m_UIToFp(m_Value(C)))) &&
+          C->getType()->isIntegerTy(1)) {
+        A = LHS;
+        Value *Zero = ConstantFP::getNegativeZero(A->getType());
+        return SelectInst::Create(C, Zero, A);
+      }
+    }
+
     if (!isa<Constant>(Op1))
       std::swap(Opnd0, Opnd1);
     else