[AMDGPU] New test case where we should not form FMA

GitOrigin-RevId: 92901996a63b14c3a8605652735acdaf2c20eac9

test/CodeGen/AMDGPU/dagcombine-fma-fmad.ll

diff --git a/test/CodeGen/AMDGPU/dagcombine-fma-fmad.ll b/test/CodeGen/AMDGPU/dagcombine-fma-fmad.ll
index 485b379..68cc2a1 100644
--- a/test/CodeGen/AMDGPU/dagcombine-fma-fmad.ll
+++ b/test/CodeGen/AMDGPU/dagcombine-fma-fmad.ll
@@ -274,6 +274,18 @@
   ret float %r
 }
 
+define amdgpu_ps float @fma_vs_output_modifier_2(float %x) #0 {
+; GCN-LABEL: fma_vs_output_modifier_2:
+; GCN:       ; %bb.0:
+; GCN-NEXT:    v_mul_f32_e32 v1, v0, v0
+; GCN-NEXT:    v_fmac_f32_e32 v1, v0, v0
+; GCN-NEXT:    v_mov_b32_e32 v0, v1
+; GCN-NEXT:    ; return to shader part epilog
+  %m = fmul contract float %x, %x
+  %a = fadd nsz contract float %m, %m
+  ret float %a
+}
+
 ; Function Attrs: nofree nosync nounwind readnone speculatable willreturn
 declare float @llvm.maxnum.f32(float, float) #1