xref: /llvm-project/llvm/test/CodeGen/X86/neg_fp.ll (revision a2a0089ac3a5781ba74d4d319c87c9e8b46d4eda)
1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
2; RUN: llc < %s -mtriple=i686-- -mattr=+sse4.1 | FileCheck %s
3
4; Test that when we don't -enable-unsafe-fp-math, we don't do the optimization
5; -0 - (A - B) to (B - A) because A==B, -0 != 0
6
7define float @negfp(float %a, float %b) nounwind {
8; CHECK-LABEL: negfp:
9; CHECK:       # %bb.0: # %entry
10; CHECK-NEXT:    pushl %eax
11; CHECK-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
12; CHECK-NEXT:    subss {{[0-9]+}}(%esp), %xmm0
13; CHECK-NEXT:    xorps {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
14; CHECK-NEXT:    movss %xmm0, (%esp)
15; CHECK-NEXT:    flds (%esp)
16; CHECK-NEXT:    popl %eax
17; CHECK-NEXT:    retl
18entry:
19	%sub = fsub float %a, %b		; <float> [#uses=1]
20	%neg = fsub float -0.000000e+00, %sub		; <float> [#uses=1]
21	ret float %neg
22}
23
24; This may infinite loop if isNegatibleForFree and getNegatedExpression are conflicted.
25
26define double @negation_propagation(ptr %arg, double %arg1, double %arg2) nounwind {
27; CHECK-LABEL: negation_propagation:
28; CHECK:       # %bb.0:
29; CHECK-NEXT:    pushl %ebp
30; CHECK-NEXT:    movl %esp, %ebp
31; CHECK-NEXT:    andl $-8, %esp
32; CHECK-NEXT:    subl $8, %esp
33; CHECK-NEXT:    movsd {{.*#+}} xmm0 = [1.0E+0,0.0E+0]
34; CHECK-NEXT:    divsd 12(%ebp), %xmm0
35; CHECK-NEXT:    movsd {{.*#+}} xmm1 = mem[0],zero
36; CHECK-NEXT:    mulsd %xmm0, %xmm1
37; CHECK-NEXT:    movapd %xmm0, %xmm2
38; CHECK-NEXT:    mulsd %xmm0, %xmm2
39; CHECK-NEXT:    mulsd %xmm0, %xmm2
40; CHECK-NEXT:    subsd %xmm2, %xmm1
41; CHECK-NEXT:    movsd %xmm1, (%esp)
42; CHECK-NEXT:    fldl (%esp)
43; CHECK-NEXT:    movl %ebp, %esp
44; CHECK-NEXT:    popl %ebp
45; CHECK-NEXT:    retl
46  %t = fdiv double 1.0, %arg1
47  %t7 = fmul double %t, %arg2
48  %t10 = fneg double %t7
49  %t11 = fmul double %t, %t
50  %t13 = fsub double %t11, %t
51  %t14 = fneg double %t
52  %t15 = fmul double %t, %t14
53  %t16 = fmul double %t, %t15
54  %t18 = fadd double %t16, %t7
55  ret double %t18
56}
57
58; This would crash because the negated expression for %sub4
59; creates a new use of %sub1 and that alters the negated cost
60
61define float @fdiv_extra_use_changes_cost(float %a0, float %a1, float %a2) nounwind {
62; CHECK-LABEL: fdiv_extra_use_changes_cost:
63; CHECK:       # %bb.0:
64; CHECK-NEXT:    pushl %eax
65; CHECK-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
66; CHECK-NEXT:    movss {{.*#+}} xmm1 = mem[0],zero,zero,zero
67; CHECK-NEXT:    subss {{[0-9]+}}(%esp), %xmm1
68; CHECK-NEXT:    movaps %xmm1, %xmm2
69; CHECK-NEXT:    mulss %xmm0, %xmm2
70; CHECK-NEXT:    subss %xmm1, %xmm0
71; CHECK-NEXT:    divss %xmm2, %xmm0
72; CHECK-NEXT:    movss %xmm0, (%esp)
73; CHECK-NEXT:    flds (%esp)
74; CHECK-NEXT:    popl %eax
75; CHECK-NEXT:    retl
76  %sub1 = fsub fast float %a0, %a1
77  %mul2 = fmul fast float %sub1, %a2
78  %neg = fneg fast float %a0
79  %add3 = fadd fast float %a1, %neg
80  %sub4 = fadd fast float %add3, %a2
81  %div5 = fdiv fast float %sub4, %mul2
82  ret float %div5
83}
84
85; PR55758 - this is not -(-X)
86
87define <2 x i64> @fneg_mismatched_sizes(<4 x float> %x) {
88; CHECK-LABEL: fneg_mismatched_sizes:
89; CHECK:       # %bb.0:
90; CHECK-NEXT:    xorps {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
91; CHECK-NEXT:    xorps {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0
92; CHECK-NEXT:    retl
93  %n = fneg <4 x float> %x
94  %b = bitcast <4 x float> %n to <2 x i64>
95  %r = xor <2 x i64> %b, <i64 -9223372036854775808, i64 -9223372036854775808>
96  ret <2 x i64> %r
97}
98