1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -S < %s -instcombine | FileCheck %s
; Fold
; (X & C) - X
; to
; - (X & ~C)
;
; This allows us to possibly hoist said negation further out,
; and decreases use count of X.
; https://bugs.llvm.org/show_bug.cgi?id=44427
; Base tests
define i8 @t0(i8 %x) {
; CHECK-LABEL: @t0(
; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[X:%.*]], -43
; CHECK-NEXT: [[NEGBIAS:%.*]] = sub i8 0, [[TMP1]]
; CHECK-NEXT: ret i8 [[NEGBIAS]]
;
%unbiasedx = and i8 %x, 42
%negbias = sub i8 %unbiasedx, %x
ret i8 %negbias
}
define <2 x i8> @t1_vec(<2 x i8> %x) {
; CHECK-LABEL: @t1_vec(
; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i8> [[X:%.*]], <i8 -43, i8 -43>
; CHECK-NEXT: [[NEGBIAS:%.*]] = sub <2 x i8> zeroinitializer, [[TMP1]]
; CHECK-NEXT: ret <2 x i8> [[NEGBIAS]]
;
%unbiasedx = and <2 x i8> %x, <i8 42, i8 42>
%negbias = sub <2 x i8> %unbiasedx, %x
ret <2 x i8> %negbias
}
define <2 x i8> @t2_vec_undef(<2 x i8> %x) {
; CHECK-LABEL: @t2_vec_undef(
; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i8> [[X:%.*]], <i8 -43, i8 undef>
; CHECK-NEXT: [[NEGBIAS:%.*]] = sub <2 x i8> zeroinitializer, [[TMP1]]
; CHECK-NEXT: ret <2 x i8> [[NEGBIAS]]
;
%unbiasedx = and <2 x i8> %x, <i8 42, i8 undef>
%negbias = sub <2 x i8> %unbiasedx, %x
ret <2 x i8> %negbias
}
define <2 x i8> @t3_vec_nonsplat(<2 x i8> %x) {
; CHECK-LABEL: @t3_vec_nonsplat(
; CHECK-NEXT: [[TMP1:%.*]] = and <2 x i8> [[X:%.*]], <i8 -43, i8 -45>
; CHECK-NEXT: [[NEGBIAS:%.*]] = sub <2 x i8> zeroinitializer, [[TMP1]]
; CHECK-NEXT: ret <2 x i8> [[NEGBIAS]]
;
%unbiasedx = and <2 x i8> %x, <i8 42, i8 44>
%negbias = sub <2 x i8> %unbiasedx, %x
ret <2 x i8> %negbias
}
; Extra uses always prevent fold
declare void @use8(i8)
define i8 @n4_extrause(i8 %x) {
; CHECK-LABEL: @n4_extrause(
; CHECK-NEXT: [[UNBIASEDX:%.*]] = and i8 [[X:%.*]], 42
; CHECK-NEXT: call void @use8(i8 [[UNBIASEDX]])
; CHECK-NEXT: [[NEGBIAS:%.*]] = sub i8 [[UNBIASEDX]], [[X]]
; CHECK-NEXT: ret i8 [[NEGBIAS]]
;
%unbiasedx = and i8 %x, 42
call void @use8(i8 %unbiasedx)
%negbias = sub i8 %unbiasedx, %x
ret i8 %negbias
}
; Negative tests
define i8 @n5(i8 %x) {
; CHECK-LABEL: @n5(
; CHECK-NEXT: [[NEGBIAS:%.*]] = and i8 [[X:%.*]], -43
; CHECK-NEXT: ret i8 [[NEGBIAS]]
;
%unbiasedx = and i8 %x, 42
%negbias = sub i8 %x, %unbiasedx ; wrong order
ret i8 %negbias
}
define i8 @n6(i8 %x0, i8 %x1) {
; CHECK-LABEL: @n6(
; CHECK-NEXT: [[UNBIASEDX:%.*]] = and i8 [[X1:%.*]], 42
; CHECK-NEXT: [[NEGBIAS:%.*]] = sub i8 [[UNBIASEDX]], [[X0:%.*]]
; CHECK-NEXT: ret i8 [[NEGBIAS]]
;
%unbiasedx = and i8 %x1, 42 ; not %x0
%negbias = sub i8 %unbiasedx, %x0 ; not %x1
ret i8 %negbias
}
|
