1 files changed, 43 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index 166f8dfdb4a..a2c545f0119 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -1262,6 +1262,49 @@ Instruction *InstCombiner::visitFAdd(BinaryOperator &I) {
     }
   }
 
+  // A * (1 - uitofp i1 C) + B * (uitofp i1 C) -> select C, B, A
+  {
+    if (I.hasNoNaNs() && I.hasNoInfs() && I.hasNoSignedZeros()) {
+      Value *M1L, *M1R, *M2L, *M2R;
+      if (match(LHS, m_FMul(m_Value(M1L), m_Value(M1R))) &&
+          match(RHS, m_FMul(m_Value(M2L), m_Value(M2R)))) {
+
+        Value *A, *B, *C1, *C2;
+        if (!match(M1R, m_FSub(m_FPOne(), m_UIToFp(m_Value(C1)))))
+          std::swap(M1L, M1R);
+        if (!match(M2R, m_UIToFp(m_Value(C2)))) 
+          std::swap(M2L, M2R);
+
+        if (match(M1R, m_FSub(m_FPOne(), m_UIToFp(m_Value(C1)))) &&
+            match(M2R, m_UIToFp(m_Value(C2))) &&
+            C2->getType()->isIntegerTy(1) &&
+            C1 == C2) {
+          A = M1L;
+          B = M2L;
+          return SelectInst::Create(C1, B, A);
+        }
+        
+        std::swap(M1L, M2L);
+        std::swap(M1R, M2R);
+        
+        if (!match(M1R, m_FSub(m_FPOne(), m_UIToFp(m_Value(C1)))))
+          std::swap(M1L, M1R);
+        if (!match(M2R, m_UIToFp(m_Value(C2)))) 
+          std::swap(M2L, M2R);
+
+        if (match(M1R, m_FSub(m_FPOne(), m_UIToFp(m_Value(C1)))) &&
+            match(M2R, m_UIToFp(m_Value(C2))) &&
+            C2->getType()->isIntegerTy(1) &&
+            C1 == C2) {
+          A = M1L;
+          B = M2L;
+          return SelectInst::Create(C1, B, A);
+        }
+      }
+    }
+  }
+
+  
   if (I.hasUnsafeAlgebra()) {
     if (Value *V = FAddCombine(Builder).simplify(&I))
       return ReplaceInstUsesWith(I, V);