Commit be8f217b authored by Craig Topper's avatar Craig Topper
Browse files

[X86] Don't call LowerUINT_TO_FP_i32 for i32->f80 on 32-bit targets with sse2. 

We were performing an emulated i32->f64 in the SSE registers, then
storing that value to memory and doing a extload into the X87
domain.

After this patch we'll now just store the i32 to memory along
with an i32 0. Then do a 64-bit FILD to f80 completely in the X87
unit. This matches what we do without SSE.
parent 1b264a82

llvm/lib/Target/X86/X86ISelLowering.cpp

+1 −1
Original line number Diff line number Diff line
@@ -19331,7 +19331,7 @@ SDValue X86TargetLowering::LowerUINT_TO_FP(SDValue Op, 














  if (SrcVT == MVT::i64 && DstVT == MVT::f64 && X86ScalarSSEf64)















    return LowerUINT_TO_FP_i64(Op, DAG, Subtarget);













  if (SrcVT == MVT::i32 && X86ScalarSSEf64)













  if (SrcVT == MVT::i32 && X86ScalarSSEf64 && DstVT != MVT::f80)















    return LowerUINT_TO_FP_i32(Op, DAG, Subtarget);















  if (Subtarget.is64Bit() && SrcVT == MVT::i64 && DstVT == MVT::f32)















    return SDValue();

























llvm/test/CodeGen/X86/scalar-int-to-fp.ll



+13
−45






























Original line number
Diff line number
Diff line








@@ -214,21 +214,19 @@ define double @s32_to_d(i32 %a) nounwind {













}































define x86_fp80 @u32_to_x(i32 %a) nounwind {













; AVX512_32-LABEL: u32_to_x:













; AVX512_32:       # %bb.0:













; AVX512_32-NEXT:    pushl %ebp













; AVX512_32-NEXT:    movl %esp, %ebp













; AVX512_32-NEXT:    andl $-8, %esp













; AVX512_32-NEXT:    subl $8, %esp













; AVX512_32-NEXT:    vmovsd {{.*#+}} xmm0 = mem[0],zero













; AVX512_32-NEXT:    vmovss {{.*#+}} xmm1 = mem[0],zero,zero,zero













; AVX512_32-NEXT:    vorpd %xmm0, %xmm1, %xmm1













; AVX512_32-NEXT:    vsubsd %xmm0, %xmm1, %xmm0













; AVX512_32-NEXT:    vmovsd %xmm0, (%esp)













; AVX512_32-NEXT:    fldl (%esp)













; AVX512_32-NEXT:    movl %ebp, %esp













; AVX512_32-NEXT:    popl %ebp













; AVX512_32-NEXT:    retl













; CHECK32-LABEL: u32_to_x:













; CHECK32:       # %bb.0:













; CHECK32-NEXT:    pushl %ebp













; CHECK32-NEXT:    movl %esp, %ebp













; CHECK32-NEXT:    andl $-8, %esp













; CHECK32-NEXT:    subl $8, %esp













; CHECK32-NEXT:    movl 8(%ebp), %eax













; CHECK32-NEXT:    movl %eax, (%esp)













; CHECK32-NEXT:    movl $0, {{[0-9]+}}(%esp)













; CHECK32-NEXT:    fildll (%esp)













; CHECK32-NEXT:    movl %ebp, %esp













; CHECK32-NEXT:    popl %ebp













; CHECK32-NEXT:    retl















;















; CHECK64-LABEL: u32_to_x:















; CHECK64:       # %bb.0:









@@ -236,36 +234,6 @@ define x86_fp80 @u32_to_x(i32 %a) nounwind {













; CHECK64-NEXT:    movq %rax, -{{[0-9]+}}(%rsp)















; CHECK64-NEXT:    fildll -{{[0-9]+}}(%rsp)















; CHECK64-NEXT:    retq













;













; SSE2_32-LABEL: u32_to_x:













; SSE2_32:       # %bb.0:













; SSE2_32-NEXT:    pushl %ebp













; SSE2_32-NEXT:    movl %esp, %ebp













; SSE2_32-NEXT:    andl $-8, %esp













; SSE2_32-NEXT:    subl $8, %esp













; SSE2_32-NEXT:    movsd {{.*#+}} xmm0 = mem[0],zero













; SSE2_32-NEXT:    movss {{.*#+}} xmm1 = mem[0],zero,zero,zero













; SSE2_32-NEXT:    orpd %xmm0, %xmm1













; SSE2_32-NEXT:    subsd %xmm0, %xmm1













; SSE2_32-NEXT:    movsd %xmm1, (%esp)













; SSE2_32-NEXT:    fldl (%esp)













; SSE2_32-NEXT:    movl %ebp, %esp













; SSE2_32-NEXT:    popl %ebp













; SSE2_32-NEXT:    retl













;













; X87-LABEL: u32_to_x:













; X87:       # %bb.0:













; X87-NEXT:    pushl %ebp













; X87-NEXT:    movl %esp, %ebp













; X87-NEXT:    andl $-8, %esp













; X87-NEXT:    subl $8, %esp













; X87-NEXT:    movl 8(%ebp), %eax













; X87-NEXT:    movl %eax, (%esp)













; X87-NEXT:    movl $0, {{[0-9]+}}(%esp)













; X87-NEXT:    fildll (%esp)













; X87-NEXT:    movl %ebp, %esp













; X87-NEXT:    popl %ebp













; X87-NEXT:    retl















  %r = uitofp i32 %a to x86_fp80















  ret x86_fp80 %r















}