Index: lib/CodeGen/CGExprScalar.cpp
===================================================================
--- lib/CodeGen/CGExprScalar.cpp
+++ lib/CodeGen/CGExprScalar.cpp
@@ -256,8 +256,22 @@
   //                            Visitor Methods
   //===--------------------------------------------------------------------===//
 
+  /// A RAII to apply the FP features from the expression to the IRBuilder.
+  struct ApplyFPFeatures : public CGBuilderTy::FastMathFlagGuard {
+    ApplyFPFeatures(llvm::IRBuilderBase &Builder, Expr *E)
+        : CGBuilderTy::FastMathFlagGuard(Builder) {
+      if (const auto *BO = dyn_cast<BinaryOperator>(E)) {
+        llvm::FastMathFlags FMF = Builder.getFastMathFlags();
+        FMF.setAllowContract(
+            BO->getFPFeatures().allowFPContractAcrossStatement());
+        Builder.setFastMathFlags(FMF);
+      }
+    }
+  };
+
   Value *Visit(Expr *E) {
     ApplyDebugLocation DL(CGF, E);
+    ApplyFPFeatures FPF(Builder, E);
     return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E);
   }