extract-lowbits-variablemask.ll
3.48 KB
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
; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
; RUN: opt -S -analyze -scalar-evolution < %s | FileCheck %s
; These testcases aren't *identical* but they have the same/similar meaning.
; The obvious case.
define i32 @mul(i32 %val, i32 %num) nounwind {
; CHECK-LABEL: 'mul'
; CHECK-NEXT: Classifying expressions for: @mul
; CHECK-NEXT: %tmp1 = mul i32 %val, %num
; CHECK-NEXT: --> (%val * %num) U: full-set S: full-set
; CHECK-NEXT: %tmp2 = udiv i32 %tmp1, %num
; CHECK-NEXT: --> ((%val * %num) /u %num) U: full-set S: full-set
; CHECK-NEXT: Determining loop execution counts for: @mul
;
%tmp1 = mul i32 %val, %num
%tmp2 = udiv i32 %tmp1, %num
ret i32 %tmp2
}
; Or, it could be any number of equivalent patterns with mask:
; a) x & (1 << nbits) - 1
; b) x & ~(-1 << nbits)
; c) x & (-1 >> (32 - y))
; d) x << (32 - y) >> (32 - y)
define i32 @mask_a(i32 %val, i32 %numlowbits) nounwind {
; CHECK-LABEL: 'mask_a'
; CHECK-NEXT: Classifying expressions for: @mask_a
; CHECK-NEXT: %onebit = shl i32 1, %numlowbits
; CHECK-NEXT: --> %onebit U: full-set S: full-set
; CHECK-NEXT: %mask = add nsw i32 %onebit, -1
; CHECK-NEXT: --> (-1 + %onebit) U: full-set S: full-set
; CHECK-NEXT: %masked = and i32 %mask, %val
; CHECK-NEXT: --> %masked U: full-set S: full-set
; CHECK-NEXT: Determining loop execution counts for: @mask_a
;
%onebit = shl i32 1, %numlowbits
%mask = add nsw i32 %onebit, -1
%masked = and i32 %mask, %val
ret i32 %masked
}
define i32 @mask_b(i32 %val, i32 %numlowbits) nounwind {
; CHECK-LABEL: 'mask_b'
; CHECK-NEXT: Classifying expressions for: @mask_b
; CHECK-NEXT: %notmask = shl i32 -1, %numlowbits
; CHECK-NEXT: --> %notmask U: full-set S: full-set
; CHECK-NEXT: %mask = xor i32 %notmask, -1
; CHECK-NEXT: --> (-1 + (-1 * %notmask)) U: full-set S: full-set
; CHECK-NEXT: %masked = and i32 %mask, %val
; CHECK-NEXT: --> %masked U: full-set S: full-set
; CHECK-NEXT: Determining loop execution counts for: @mask_b
;
%notmask = shl i32 -1, %numlowbits
%mask = xor i32 %notmask, -1
%masked = and i32 %mask, %val
ret i32 %masked
}
define i32 @mask_c(i32 %val, i32 %numlowbits) nounwind {
; CHECK-LABEL: 'mask_c'
; CHECK-NEXT: Classifying expressions for: @mask_c
; CHECK-NEXT: %numhighbits = sub i32 32, %numlowbits
; CHECK-NEXT: --> (32 + (-1 * %numlowbits)) U: full-set S: full-set
; CHECK-NEXT: %mask = lshr i32 -1, %numhighbits
; CHECK-NEXT: --> %mask U: full-set S: full-set
; CHECK-NEXT: %masked = and i32 %mask, %val
; CHECK-NEXT: --> %masked U: full-set S: full-set
; CHECK-NEXT: Determining loop execution counts for: @mask_c
;
%numhighbits = sub i32 32, %numlowbits
%mask = lshr i32 -1, %numhighbits
%masked = and i32 %mask, %val
ret i32 %masked
}
define i32 @mask_d(i32 %val, i32 %numlowbits) nounwind {
; CHECK-LABEL: 'mask_d'
; CHECK-NEXT: Classifying expressions for: @mask_d
; CHECK-NEXT: %numhighbits = sub i32 32, %numlowbits
; CHECK-NEXT: --> (32 + (-1 * %numlowbits)) U: full-set S: full-set
; CHECK-NEXT: %highbitscleared = shl i32 %val, %numhighbits
; CHECK-NEXT: --> %highbitscleared U: full-set S: full-set
; CHECK-NEXT: %masked = lshr i32 %highbitscleared, %numhighbits
; CHECK-NEXT: --> %masked U: full-set S: full-set
; CHECK-NEXT: Determining loop execution counts for: @mask_d
;
%numhighbits = sub i32 32, %numlowbits
%highbitscleared = shl i32 %val, %numhighbits
%masked = lshr i32 %highbitscleared, %numhighbits
ret i32 %masked
}