diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -11953,6 +11953,7 @@
   // Always prefer FMAD to FMA for precision.
   unsigned PreferredFusedOpcode = HasFMAD ? ISD::FMAD : ISD::FMA;
   bool Aggressive = TLI.enableAggressiveFMAFusion(VT);
+  bool NoSignedZero = Options.NoSignedZerosFPMath || Flags.hasNoSignedZeros();
 
   // Is the node an FMUL and contractable either due to global flags or
   // SDNodeFlags.
@@ -12116,7 +12117,7 @@
     //   -> (fma (fneg y), z, (fma (fneg u), v, x))
     if (CanFuse && N1.getOpcode() == PreferredFusedOpcode &&
         isContractableFMUL(N1.getOperand(2)) &&
-        N1->hasOneUse()) {
+        N1->hasOneUse() && NoSignedZero) {
       SDValue N20 = N1.getOperand(2).getOperand(0);
       SDValue N21 = N1.getOperand(2).getOperand(1);
       return DAG.getNode(PreferredFusedOpcode, SL, VT,
diff --git a/llvm/test/CodeGen/AMDGPU/fma-combine.ll b/llvm/test/CodeGen/AMDGPU/fma-combine.ll
--- a/llvm/test/CodeGen/AMDGPU/fma-combine.ll
+++ b/llvm/test/CodeGen/AMDGPU/fma-combine.ll
@@ -376,9 +376,10 @@
   %u = load volatile double, double addrspace(1)* %gep.3
   %v = load volatile double, double addrspace(1)* %gep.4
 
-  %tmp0 = fmul double %u, %v
-  %tmp1 = call double @llvm.fma.f64(double %y, double %z, double %tmp0) #0
-  %tmp2 = fsub double %x, %tmp1
+  ; nsz flag is needed since this combine may change sign of zero
+  %tmp0 = fmul nsz double %u, %v
+  %tmp1 = call nsz double @llvm.fma.f64(double %y, double %z, double %tmp0) #0
+  %tmp2 = fsub nsz double %x, %tmp1
 
   store double %tmp2, double addrspace(1)* %gep.out
   ret void
diff --git a/llvm/test/CodeGen/AMDGPU/mad-combine.ll b/llvm/test/CodeGen/AMDGPU/mad-combine.ll
--- a/llvm/test/CodeGen/AMDGPU/mad-combine.ll
+++ b/llvm/test/CodeGen/AMDGPU/mad-combine.ll
@@ -566,9 +566,10 @@
   %u = load volatile float, float addrspace(1)* %gep.3
   %v = load volatile float, float addrspace(1)* %gep.4
 
-  %tmp0 = fmul float %u, %v
-  %tmp1 = call float @llvm.fmuladd.f32(float %y, float %z, float %tmp0) #0
-  %tmp2 = fsub float %x, %tmp1
+  ; nsz flag is needed since this combine may change sign of zero
+  %tmp0 = fmul nsz float %u, %v
+  %tmp1 = call nsz float @llvm.fmuladd.f32(float %y, float %z, float %tmp0) #0
+  %tmp2 = fsub nsz float %x, %tmp1
 
   store float %tmp2, float addrspace(1)* %gep.out
   ret void
diff --git a/llvm/test/CodeGen/PowerPC/fma-assoc.ll b/llvm/test/CodeGen/PowerPC/fma-assoc.ll
--- a/llvm/test/CodeGen/PowerPC/fma-assoc.ll
+++ b/llvm/test/CodeGen/PowerPC/fma-assoc.ll
@@ -110,8 +110,9 @@
 ; CHECK-SAFE-NEXT: blr
 
 ; CHECK-UNSAFE-LABEL: test_FMSUB_ASSOC2:
-; CHECK-UNSAFE: fnmsub
-; CHECK-UNSAFE-NEXT: fnmsub
+; CHECK-UNSAFE: fmul
+; CHECK-UNSAFE-NEXT: fmadd
+; CHECK-UNSAFE-NEXT: fsub
 ; CHECK-UNSAFE-NEXT: blr
 
 ; CHECK-SAFE-VSX-LABEL: test_FMSUB_ASSOC2:
@@ -121,6 +122,37 @@
 ; CHECK-SAFE-VSX-NEXT: blr
 
 ; CHECK-UNSAFE-VSX-LABEL: test_FMSUB_ASSOC2:
+; CHECK-UNSAFE-VSX: xsmuldp
+; CHECK-UNSAFE-VSX-NEXT: xsmaddadp
+; CHECK-UNSAFE-VSX-NEXT: xssubdp
+; CHECK-UNSAFE-VSX-NEXT: blr
+}
+
+define double @test_FMSUB_ASSOC2_NSZ(double %A, double %B, double %C,
+                                     double %D, double %E) {
+  %F = fmul nsz double %A, %B         ; <double> [#uses=1]
+  %G = fmul nsz double %C, %D         ; <double> [#uses=1]
+  %H = fadd nsz double %F, %G         ; <double> [#uses=1]
+  %I = fsub nsz double %E, %H         ; <double> [#uses=1]
+  ret double %I
+; CHECK-SAFE-LABEL: test_FMSUB_ASSOC2_NSZ:
+; CHECK-SAFE: fmul
+; CHECK-SAFE-NEXT: fmadd
+; CHECK-SAFE-NEXT: fsub
+; CHECK-SAFE-NEXT: blr
+
+; CHECK-UNSAFE-LABEL: test_FMSUB_ASSOC2_NSZ:
+; CHECK-UNSAFE: fnmsub
+; CHECK-UNSAFE-NEXT: fnmsub
+; CHECK-UNSAFE-NEXT: blr
+
+; CHECK-SAFE-VSX-LABEL: test_FMSUB_ASSOC2_NSZ:
+; CHECK-SAFE-VSX: xsmuldp
+; CHECK-SAFE-VSX-NEXT: xsmaddadp
+; CHECK-SAFE-VSX-NEXT: xssubdp
+; CHECK-SAFE-VSX-NEXT: blr
+
+; CHECK-UNSAFE-VSX-LABEL: test_FMSUB_ASSOC2_NSZ:
 ; CHECK-UNSAFE-VSX: xsnmsubmdp
 ; CHECK-UNSAFE-VSX-NEXT: xsnmsubadp
 ; CHECK-UNSAFE-VSX-NEXT: fmr