llvm-6502/test/CodeGen/X86/sse_partial_update.ll
Sanjay Patel 956d6f0cf5 Model sqrtsd as a binary operation with one source operand tied to the destination (PR14221)
This patch fixes the following miscompile:

define void @sqrtsd(<2 x double> %a) nounwind uwtable ssp {
  %0 = tail call <2 x double> @llvm.x86.sse2.sqrt.sd(<2 x double> %a) nounwind 
  %a0 = extractelement <2 x double> %0, i32 0
  %conv = fptrunc double %a0 to float
  %a1 = extractelement <2 x double> %0, i32 1
  %conv3 = fptrunc double %a1 to float
  tail call void @callee2(float %conv, float %conv3) nounwind
  ret void
}

Current codegen:

sqrtsd	%xmm0, %xmm1        ## high element of %xmm1 is undef here
xorps	%xmm0, %xmm0
cvtsd2ss	%xmm1, %xmm0
shufpd	$1, %xmm1, %xmm1
cvtsd2ss	%xmm1, %xmm1 ## operating on undef value
jmp	_callee

This is a continuation of http://llvm.org/viewvc/llvm-project?view=revision&revision=224624 ( http://reviews.llvm.org/D6330 ) 
which was itself a continuation of r167064 ( http://llvm.org/viewvc/llvm-project?view=revision&revision=167064 ).

All of these patches are partial fixes for PR14221 ( http://llvm.org/bugs/show_bug.cgi?id=14221 ); 
this should be the final patch needed to resolve that bug.

Differential Revision: http://reviews.llvm.org/D6885



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@227111 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-26 18:42:16 +00:00

93 lines
3.1 KiB
LLVM

; RUN: llc < %s -mtriple=x86_64-apple-macosx -mattr=+sse2 -mcpu=nehalem | FileCheck %s
; rdar: 12558838
; PR14221
; 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 each scalar unary op are the same.
define void @rsqrtss(<4 x float> %a) nounwind uwtable ssp {
entry:
; CHECK-LABEL: rsqrtss:
; CHECK: rsqrtss %xmm0, %xmm0
; CHECK-NEXT: cvtss2sd %xmm0
; CHECK-NEXT: movshdup
; 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
%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 void @callee(double, double)
declare <4 x float> @llvm.x86.sse.rsqrt.ss(<4 x float>) nounwind readnone
define void @rcpss(<4 x float> %a) nounwind uwtable ssp {
entry:
; CHECK-LABEL: rcpss:
; CHECK: rcpss %xmm0, %xmm0
; CHECK-NEXT: cvtss2sd %xmm0
; CHECK-NEXT: movshdup
; 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
%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.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: movshdup
; 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
define void @sqrtsd(<2 x double> %a) nounwind uwtable ssp {
entry:
; CHECK-LABEL: sqrtsd:
; CHECK: sqrtsd %xmm0, %xmm0
; CHECK-NEXT: cvtsd2ss %xmm0
; CHECK-NEXT: shufpd
; CHECK-NEXT: cvtsd2ss %xmm0
; CHECK-NEXT: movap
; CHECK-NEXT: jmp
%0 = tail call <2 x double> @llvm.x86.sse2.sqrt.sd(<2 x double> %a) nounwind
%a0 = extractelement <2 x double> %0, i32 0
%conv = fptrunc double %a0 to float
%a1 = extractelement <2 x double> %0, i32 1
%conv3 = fptrunc double %a1 to float
tail call void @callee2(float %conv, float %conv3) nounwind
ret void
}
declare void @callee2(float, float)
declare <2 x double> @llvm.x86.sse2.sqrt.sd(<2 x double>) nounwind readnone