Index: lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -4438,28 +4438,37 @@
            N1.getValueType() == VT && "Binary operator types must match!");
     break;
   case ISD::FADD:
+    if (getTarget().Options.UnsafeFPMath ||
+        Flags.hasNoSignedZeros()) {
+      // x+0 --> x
+      if (N2CFP && N2CFP->getValueAPF().isZero())
+        return N1;
+    }
+    assert(VT.isFloatingPoint() && "This operator only applies to FP types!");
+    assert(N1.getValueType() == N2.getValueType() &&
+           N1.getValueType() == VT && "Binary operator types must match!");
+    break;
   case ISD::FSUB:
+    // x-0 --> x
+    if (N2CFP && N2CFP->getValueAPF().isZero()) {
+      return N1;
+    }
+    assert(VT.isFloatingPoint() && "This operator only applies to FP types!");
+    assert(N1.getValueType() == N2.getValueType() &&
+           N1.getValueType() == VT && "Binary operator types must match!");
+    break;
   case ISD::FMUL:
+    if (getTarget().Options.UnsafeFPMath ||
+        (Flags.hasNoNaNs() && Flags.hasNoSignedZeros())) {
+      // x*0 --> 0
+      if (N2CFP && N2CFP->isZero())
+        return N2;
+    } else if (N2CFP && N2CFP->isExactlyValue(1.0)) {
+      // x*1 --> x
+      return N1;
+    }
   case ISD::FDIV:
   case ISD::FREM:
-    if (getTarget().Options.UnsafeFPMath) {
-      if (Opcode == ISD::FADD) {
-        // x+0 --> x
-        if (N2CFP && N2CFP->getValueAPF().isZero())
-          return N1;
-      } else if (Opcode == ISD::FSUB) {
-        // x-0 --> x
-        if (N2CFP && N2CFP->getValueAPF().isZero())
-          return N1;
-      } else if (Opcode == ISD::FMUL) {
-        // x*0 --> 0
-        if (N2CFP && N2CFP->isZero())
-          return N2;
-        // x*1 --> x
-        if (N2CFP && N2CFP->isExactlyValue(1.0))
-          return N1;
-      }
-    }
     assert(VT.isFloatingPoint() && "This operator only applies to FP types!");
     assert(N1.getValueType() == N2.getValueType() &&
            N1.getValueType() == VT && "Binary operator types must match!");
Index: test/CodeGen/X86/fp-fold.ll
===================================================================
--- test/CodeGen/X86/fp-fold.ll
+++ test/CodeGen/X86/fp-fold.ll
@@ -0,0 +1,62 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown                        | FileCheck %s --check-prefixes=ANY,STRICT
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -enable-unsafe-fp-math | FileCheck %s --check-prefixes=ANY,UNSAFE
+
+; This is duplicated from tests for InstSimplify. If you're
+; adding something here, you should probably add it there too.
+
+define float @fadd_zero_1(float %x) {
+; ANY-LABEL: fadd_zero_1:
+; ANY:       # %bb.0:
+; ANY-NEXT:    retq
+  %r = fadd nsz float %x, 0.0
+  ret float %r
+}
+
+define float @fadd_zero_2(float %x) {
+; ANY-LABEL: fadd_zero_2:
+; ANY:       # %bb.0:
+; ANY-NEXT:    retq
+  %r = fadd nsz float %x, -0.0
+  ret float %r
+}
+
+define float @fsub_zero_1(float %x) {
+; ANY-LABEL: fsub_zero_1:
+; ANY:       # %bb.0:
+; ANY-NEXT:    retq
+  %r = fsub float %x, 0.0
+  ret float %r
+}
+
+define float @fsub_zero_2(float %x) {
+; ANY-LABEL: fsub_zero_2:
+; ANY:       # %bb.0:
+; ANY-NEXT:    retq
+  %r = fsub float %x, -0.0
+  ret float %r
+}
+
+; TODO: handle x*0 for fast flags the same as unsafe
+define float @fmul_zero(float %x) {
+; STRICT-LABEL: fmul_zero:
+; STRICT:       # %bb.0:
+; STRICT:         xorps	%xmm1, %xmm1
+; STRICT:         mulss	%xmm1, %xmm0
+; STRICT-NEXT:    retq
+;
+; UNSAFE-LABEL: fmul_zero:
+; UNSAFE:       # %bb.0:
+; UNSAFE:         xorps	%xmm0, %xmm0
+; UNSAFE-NEXT:    retq
+  %r = fmul nnan nsz float %x, 0.0
+  ret float %r
+}
+
+define float @fmul_one(float %x) {
+; ANY-LABEL: fmul_one:
+; ANY:       # %bb.0:
+; ANY-NEXT:    retq
+  %r = fmul float %x, 1.0
+  ret float %r
+}