Model sqrtss as a binary operation with one source operand tied to the destination (PR14221)

This is a continuation of r167064 ( http://llvm.org/viewvc/llvm-project?view=revision&revision=167064 ).
That patch started to fix PR14221 ( http://llvm.org/bugs/show_bug.cgi?id=14221 ), but it was not completed. 

Differential Revision: http://reviews.llvm.org/D6330

llvm-svn: 224624

1 files changed, 38 insertions, 5 deletions

diff --git a/llvm/test/CodeGen/X86/sse_partial_update.ll b/llvm/test/CodeGen/X86/sse_partial_update.ll
index 2c16a554aeb..a88ab014641 100644
--- a/llvm/test/CodeGen/X86/sse_partial_update.ll
+++ b/llvm/test/CodeGen/X86/sse_partial_update.ll
@@ -5,11 +5,18 @@
 ; There is a mismatch between the intrinsic and the actual instruction.
 ; The actual instruction has a partial update of dest, while the intrinsic
 ; passes through the upper FP values. Here, we make sure the source and
-; destination of rsqrtss are the same.
-define void @t1(<4 x float> %a) nounwind uwtable ssp {
+; destination of each scalar unary op are the same.
+
+define void @rsqrtss(<4 x float> %a) nounwind uwtable ssp {
 entry:
-; CHECK-LABEL: t1:
+; CHECK-LABEL: rsqrtss:
 ; CHECK: rsqrtss %xmm0, %xmm0
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: shufps
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: movap
+; CHECK-NEXT: jmp
+
   %0 = tail call <4 x float> @llvm.x86.sse.rsqrt.ss(<4 x float> %a) nounwind
   %a.addr.0.extract = extractelement <4 x float> %0, i32 0
   %conv = fpext float %a.addr.0.extract to double
@@ -21,10 +28,16 @@ entry:
 declare void @callee(double, double)
 declare <4 x float> @llvm.x86.sse.rsqrt.ss(<4 x float>) nounwind readnone
 
-define void @t2(<4 x float> %a) nounwind uwtable ssp {
+define void @rcpss(<4 x float> %a) nounwind uwtable ssp {
 entry:
-; CHECK-LABEL: t2:
+; CHECK-LABEL: rcpss:
 ; CHECK: rcpss %xmm0, %xmm0
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: shufps
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: movap
+; CHECK-NEXT: jmp
+
   %0 = tail call <4 x float> @llvm.x86.sse.rcp.ss(<4 x float> %a) nounwind
   %a.addr.0.extract = extractelement <4 x float> %0, i32 0
   %conv = fpext float %a.addr.0.extract to double
@@ -34,3 +47,23 @@ entry:
   ret void
 }
 declare <4 x float> @llvm.x86.sse.rcp.ss(<4 x float>) nounwind readnone
+
+define void @sqrtss(<4 x float> %a) nounwind uwtable ssp {
+entry:
+; CHECK-LABEL: sqrtss:
+; CHECK: sqrtss %xmm0, %xmm0
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: shufps
+; CHECK-NEXT: cvtss2sd %xmm0
+; CHECK-NEXT: movap
+; CHECK-NEXT: jmp
+
+  %0 = tail call <4 x float> @llvm.x86.sse.sqrt.ss(<4 x float> %a) nounwind
+  %a.addr.0.extract = extractelement <4 x float> %0, i32 0
+  %conv = fpext float %a.addr.0.extract to double
+  %a.addr.4.extract = extractelement <4 x float> %0, i32 1
+  %conv3 = fpext float %a.addr.4.extract to double
+  tail call void @callee(double %conv, double %conv3) nounwind
+  ret void
+}
+declare <4 x float> @llvm.x86.sse.sqrt.ss(<4 x float>) nounwind readnone