[X86] Add tests for uitofp nneg -> sitofp; NFC

Author: goldsteinn

llvm/test/CodeGen/X86/uint_to_fp.ll

@@ -25,3 +25,73 @@ entry:
   store float %1, ptr %y
   ret void
 }
+
+define float @test_without_nneg(i32 %x) nounwind {
+; X86-LABEL: test_without_nneg:
+; X86:       ## %bb.0:
+; X86-NEXT:    pushl %eax
+; X86-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; X86-NEXT:    orpd {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
+; X86-NEXT:    subsd {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
+; X86-NEXT:    cvtsd2ss %xmm0, %xmm0
+; X86-NEXT:    movss %xmm0, (%esp)
+; X86-NEXT:    flds (%esp)
+; X86-NEXT:    popl %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: test_without_nneg:
+; X64:       ## %bb.0:
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    cvtsi2ss %rax, %xmm0
+; X64-NEXT:    retq
+  %r = uitofp i32 %x to float
+  ret float %r
+}
+
+define float @test_with_nneg(i32 %x) nounwind {
+; X86-LABEL: test_with_nneg:
+; X86:       ## %bb.0:
+; X86-NEXT:    pushl %eax
+; X86-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; X86-NEXT:    orpd {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
+; X86-NEXT:    subsd {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
+; X86-NEXT:    cvtsd2ss %xmm0, %xmm0
+; X86-NEXT:    movss %xmm0, (%esp)
+; X86-NEXT:    flds (%esp)
+; X86-NEXT:    popl %eax
+; X86-NEXT:    retl
+;
+; X64-LABEL: test_with_nneg:
+; X64:       ## %bb.0:
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    cvtsi2ss %rax, %xmm0
+; X64-NEXT:    retq
+  %r = uitofp nneg i32 %x to float
+  ret float %r
+}
+
+define <4 x float> @test_with_nneg_vec(<4 x i32> %x) nounwind {
+; X86-LABEL: test_with_nneg_vec:
+; X86:       ## %bb.0:
+; X86-NEXT:    movdqa {{.*#+}} xmm1 = [65535,65535,65535,65535]
+; X86-NEXT:    pand %xmm0, %xmm1
+; X86-NEXT:    por {{\.?LCPI[0-9]+_[0-9]+}}, %xmm1
+; X86-NEXT:    psrld $16, %xmm0
+; X86-NEXT:    por {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
+; X86-NEXT:    subps {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
+; X86-NEXT:    addps %xmm1, %xmm0
+; X86-NEXT:    retl
+;
+; X64-LABEL: test_with_nneg_vec:
+; X64:       ## %bb.0:
+; X64-NEXT:    movdqa {{.*#+}} xmm1 = [65535,65535,65535,65535]
+; X64-NEXT:    pand %xmm0, %xmm1
+; X64-NEXT:    por {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm1
+; X64-NEXT:    psrld $16, %xmm0
+; X64-NEXT:    por {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; X64-NEXT:    subps {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; X64-NEXT:    addps %xmm1, %xmm0
+; X64-NEXT:    retq
+  %r = uitofp nneg <4 x i32> %x to <4 x float>
+  ret <4 x float> %r
+}