llvm-mirror/test/CodeGen/X86/sse-fcopysign.ll
Sanjay Patel fa4a9158e9 fix invalid load folding with SSE/AVX FP logical instructions (PR22371)
This is a follow-up to the FIXME that was added with D7474 ( http://reviews.llvm.org/rL229531 ).
I thought this load folding bug had been made hard-to-hit, but it turns out to be very easy
when targeting 32-bit x86 and causes a miscompile/crash in Wine:
https://bugs.winehq.org/show_bug.cgi?id=38826
https://llvm.org/bugs/show_bug.cgi?id=22371#c25

The quick fix is to simply remove the scalar FP logical instructions from the load folding table
in X86InstrInfo, but that causes us to miss load folds that should be possible when lowering fabs,
fneg, fcopysign. So the majority of this patch is altering those lowerings to use *vector* FP
logical instructions (because that's all x86 gives us anyway). That lets us do the load folding 
legally.

Differential Revision: http://reviews.llvm.org/D11477

llvm-svn: 243361
2015-07-28 00:48:32 +00:00

135 lines
3.8 KiB
LLVM

; RUN: llc < %s -mtriple=i686-unknown -mattr=+sse2 | FileCheck %s --check-prefix=ALL --check-prefix=X32
; RUN: llc < %s -mtriple=x86_64-unknown -mattr=+sse2 | FileCheck %s --check-prefix=ALL --check-prefix=X64
;
; Library Functions
;
define float @tst1(float %a, float %b) {
; X32-LABEL: @tst1
; X32: movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
; X32-NEXT: movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
; X32-NEXT: movss %xmm1, 4(%esp)
; X32-NEXT: movss %xmm0, (%esp)
; X32-NEXT: calll copysignf
; X32-NEXT: addl $8, %esp
; X32-NEXT: retl
;
; X64-LABEL: @tst1
; X64: movaps %xmm0, %xmm2
; X64-NEXT: movaps %xmm1, %xmm0
; X64-NEXT: movaps %xmm2, %xmm1
; X64-NEXT: jmp copysignf
%tmp = tail call float @copysignf( float %b, float %a )
ret float %tmp
}
define double @tst2(double %a, float %b, float %c) {
; X32-LABEL: @tst2
; X32: movsd {{.*#+}} xmm0 = mem[0],zero
; X32-NEXT: movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
; X32-NEXT: addss 32(%esp), %xmm1
; X32-NEXT: cvtss2sd %xmm1, %xmm1
; X32-NEXT: movsd %xmm0, (%esp)
; X32-NEXT: movsd %xmm1, 8(%esp)
; X32-NEXT: calll copysign
; X32-NEXT: addl $16, %esp
; X32-NEXT: retl
;
; X64-LABEL: @tst2
; X64: addss %xmm2, %xmm1
; X64-NEXT: cvtss2sd %xmm1, %xmm1
; X64-NEXT: jmp copysign
%tmp1 = fadd float %b, %c
%tmp2 = fpext float %tmp1 to double
%tmp = tail call double @copysign( double %a, double %tmp2 )
ret double %tmp
}
declare float @copysignf(float, float)
declare double @copysign(double, double)
;
; LLVM Intrinsic
;
define float @int1(float %a, float %b) {
; X32-LABEL: @int1
; X32: movss 8(%esp), %xmm0 {{.*#+}} xmm0 = mem[0],zero,zero,zero
; X32-NEXT: andps .LCPI2_0, %xmm0
; X32-NEXT: movss 12(%esp), %xmm1 {{.*#+}} xmm1 = mem[0],zero,zero,zero
; X32-NEXT: andps .LCPI2_1, %xmm1
; X32-NEXT: orps %xmm0, %xmm1
; X32-NEXT: movss %xmm1, (%esp)
; X32-NEXT: flds (%esp)
; X32-NEXT: popl %eax
; X32-NEXT: retl
;
; X64-LABEL: @int1
; X64: andps .LCPI2_0(%rip), %xmm0
; X64-NEXT: andps .LCPI2_1(%rip), %xmm1
; X64-NEXT: orps %xmm1, %xmm0
; X64-NEXT: retq
%tmp = tail call float @llvm.copysign.f32( float %b, float %a )
ret float %tmp
}
define double @int2(double %a, float %b, float %c) {
; X32-LABEL: @int2
; X32: movss 16(%ebp), %xmm0 {{.*#+}} xmm0 = mem[0],zero,zero,zero
; X32-NEXT: addss 20(%ebp), %xmm0
; X32-NEXT: movsd 8(%ebp), %xmm1 {{.*#+}} xmm1 = mem[0],zero
; X32-NEXT: andpd .LCPI3_0, %xmm1
; X32-NEXT: cvtss2sd %xmm0, %xmm0
; X32-NEXT: andpd .LCPI3_1, %xmm0
; X32-NEXT: orpd %xmm1, %xmm0
; X32-NEXT: movlpd %xmm0, (%esp)
; X32-NEXT: fldl (%esp)
; X32-NEXT: movl %ebp, %esp
; X32-NEXT: popl %ebp
; X32-NEXT: retl
;
; X64-LABEL: @int2
; X64: addss %xmm2, %xmm1
; X64-NEXT: cvtss2sd %xmm1, %xmm1
; X64-NEXT: andpd .LCPI3_0(%rip), %xmm1
; X64-NEXT: andpd .LCPI3_1(%rip), %xmm0
; X64-NEXT: orpd %xmm1, %xmm0
; X64-NEXT: retq
%tmp1 = fadd float %b, %c
%tmp2 = fpext float %tmp1 to double
%tmp = tail call double @llvm.copysign.f64( double %a, double %tmp2 )
ret double %tmp
}
define float @cst1() {
; X32-LABEL: @cst1
; X32: fld1
; X32-NEXT: fchs
; X32-NEXT: retl
;
; X64-LABEL: @cst1
; X64: movss .LCPI4_0(%rip), %xmm0 {{.*#+}} xmm0 = mem[0],zero,zero,zero
; X64-NEXT: retq
%tmp = tail call float @llvm.copysign.f32( float 1.0, float -2.0 )
ret float %tmp
}
define double @cst2() {
; X32-LABEL: @cst2
; X32: fldz
; X32-NEXT: fchs
; X32-NEXT: retl
;
; X64-LABEL: @cst2
; X64: movsd .LCPI5_0(%rip), %xmm0 {{.*#+}} xmm0 = mem[0],zero
; X64-NEXT: retq
%tmp1 = fadd float -1.0, -1.0
%tmp2 = fpext float %tmp1 to double
%tmp = tail call double @llvm.copysign.f64( double 0.0, double %tmp2 )
ret double %tmp
}
declare float @llvm.copysign.f32(float %Mag, float %Sgn)
declare double @llvm.copysign.f64(double %Mag, double %Sgn)