xref: /llvm-project/llvm/test/CodeGen/X86/fdiv.ll (revision 0aef747b846586c29ed3285bbed20a3d607576fa)
1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
2; RUN: llc < %s -mtriple=x86_64-unknown-unknown -enable-unsafe-fp-math | FileCheck %s
3
4define double @exact(double %x) {
5; Exact division by a constant converted to multiplication.
6; CHECK-LABEL: exact:
7; CHECK:       # %bb.0:
8; CHECK-NEXT:    mulsd {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
9; CHECK-NEXT:    retq
10  %div = fdiv double %x, 2.0
11  ret double %div
12}
13
14define double @inexact(double %x) {
15; Inexact division by a constant converted to multiplication.
16; CHECK-LABEL: inexact:
17; CHECK:       # %bb.0:
18; CHECK-NEXT:    mulsd {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
19; CHECK-NEXT:    retq
20  %div = fdiv double %x, 0x41DFFFFFFFC00000
21  ret double %div
22}
23
24define double @funky(double %x) {
25; No conversion to multiplication if too funky.
26; CHECK-LABEL: funky:
27; CHECK:       # %bb.0:
28; CHECK-NEXT:    xorpd %xmm1, %xmm1
29; CHECK-NEXT:    divsd %xmm1, %xmm0
30; CHECK-NEXT:    retq
31  %div = fdiv double %x, 0.0
32  ret double %div
33}
34
35define double @denormal1(double %x) {
36; Don't generate multiplication by a denormal.
37; CHECK-LABEL: denormal1:
38; CHECK:       # %bb.0:
39; CHECK-NEXT:    divsd {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
40; CHECK-NEXT:    retq
41  %div = fdiv double %x, 0x7FD0000000000001
42  ret double %div
43}
44
45define double @denormal2(double %x) {
46; Don't generate multiplication by a denormal.
47; CHECK-LABEL: denormal2:
48; CHECK:       # %bb.0:
49; CHECK-NEXT:    divsd {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
50; CHECK-NEXT:    retq
51  %div = fdiv double %x, 0x7FEFFFFFFFFFFFFF
52  ret double %div
53}
54
55; Deleting the negates does not require unsafe-fp-math.
56
57define float @double_negative(float %x, float %y) #0 {
58; CHECK-LABEL: double_negative:
59; CHECK:       # %bb.0:
60; CHECK-NEXT:    divss %xmm1, %xmm0
61; CHECK-NEXT:    retq
62  %neg1 = fsub float -0.0, %x
63  %neg2 = fsub float -0.0, %y
64  %div = fdiv float %neg1, %neg2
65  ret float %div
66}
67
68define <4 x float> @double_negative_vector(<4 x float> %x, <4 x float> %y) #0 {
69; CHECK-LABEL: double_negative_vector:
70; CHECK:       # %bb.0:
71; CHECK-NEXT:    divps %xmm1, %xmm0
72; CHECK-NEXT:    retq
73  %neg1 = fsub <4 x float> <float -0.0, float -0.0, float -0.0, float -0.0>, %x
74  %neg2 = fsub <4 x float> <float -0.0, float -0.0, float -0.0, float -0.0>, %y
75  %div = fdiv <4 x float> %neg1, %neg2
76  ret <4 x float> %div
77}
78
79; This test used to fail, depending on how llc was built (e.g. using
80; clang/gcc), due to order of argument evaluation not being well defined. We
81; ended up hitting llvm_unreachable in getNegatedExpression when building with
82; gcc. Just make sure that we get a deterministic result.
83define float @fdiv_fneg_combine(float %a0, float %a1, float %a2) #0 {
84; CHECK-LABEL: fdiv_fneg_combine:
85; CHECK:       # %bb.0:
86; CHECK-NEXT:    movaps %xmm0, %xmm3
87; CHECK-NEXT:    subss %xmm1, %xmm3
88; CHECK-NEXT:    subss %xmm0, %xmm1
89; CHECK-NEXT:    mulss %xmm2, %xmm1
90; CHECK-NEXT:    subss %xmm2, %xmm3
91; CHECK-NEXT:    divss %xmm3, %xmm1
92; CHECK-NEXT:    movaps %xmm1, %xmm0
93; CHECK-NEXT:    retq
94  %sub1 = fsub fast float %a0, %a1
95  %mul2 = fmul fast float %sub1, %a2
96  %neg = fneg fast float %a0
97  %add3 = fadd fast float %a1, %neg
98  %sub4 = fadd fast float %add3, %a2
99  %div5 = fdiv fast float %mul2, %sub4
100  ret float %div5
101}
102
103attributes #0 = { "unsafe-fp-math"="false" }
104
105