1 files changed, 30 insertions, 0 deletions
diff --git a/test/CodeGen/X86/fma-do-not-commute.ll b/test/CodeGen/X86/fma-do-not-commute.ll
new file mode 100644
index 0000000..4e21172
--- /dev/null
+++ b/test/CodeGen/X86/fma-do-not-commute.ll
@@ -0,0 +1,30 @@
+; RUN: llc -fp-contract=fast -mattr=+fma -disable-cgp < %s -o - | FileCheck %s
+; Check that the 2nd and 3rd arguments of fmaXXX231 reg1, reg2, mem3 are not commuted.
+; <rdar://problem/16800495> 
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx"
+
+; CHECK-LABEL: test1:
+; %arg lives in xmm0 and it shouldn't be redefined until it is used in the FMA.
+; CHECK-NOT {{.*}}, %xmm0
+; %addr lives in rdi.
+; %addr2 lives in rsi.
+; CHECK: vmovss (%rsi), [[ADDR2:%xmm[0-9]+]]
+; The assembly syntax is in the reverse order.
+; CHECK: vfmadd231ss (%rdi), [[ADDR2]], %xmm0
+define void @test1(float* %addr, float* %addr2, float %arg) {
+entry:
+  br label %loop
+
+loop:
+  %sum0 = phi float [ %fma, %loop ], [ %arg, %entry ]
+  %addrVal = load float* %addr, align 4
+  %addr2Val = load float* %addr2, align 4
+  %fmul = fmul float %addrVal, %addr2Val
+  %fma = fadd float %sum0, %fmul
+  br i1 true, label %exit, label %loop
+
+exit:
+  store float %fma, float* %addr, align 4
+  ret void
+}