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
99
100
101
102
103
104
|
; Test that the strcmp library call simplifier works correctly.
; RUN: opt < %s -instcombine -S | FileCheck %s --check-prefix=NOBCMP
; RUN: opt < %s -instcombine -mtriple=unknown-unknown-linux-gnu -S | FileCheck %s --check-prefix=BCMP
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
@hello = constant [6 x i8] c"hello\00"
@hell = constant [5 x i8] c"hell\00"
@bell = constant [5 x i8] c"bell\00"
@null = constant [1 x i8] zeroinitializer
declare i32 @strcmp(i8*, i8*)
; strcmp("", x) -> -*x
define i32 @test1(i8* %str2) {
; CHECK-LABEL: @test1(
; CHECK: %strcmpload = load i8, i8* %str
; CHECK: %1 = zext i8 %strcmpload to i32
; CHECK: %2 = sub nsw i32 0, %1
; CHECK: ret i32 %2
%str1 = getelementptr inbounds [1 x i8], [1 x i8]* @null, i32 0, i32 0
%temp1 = call i32 @strcmp(i8* %str1, i8* %str2)
ret i32 %temp1
}
; strcmp(x, "") -> *x
define i32 @test2(i8* %str1) {
; CHECK-LABEL: @test2(
; CHECK: %strcmpload = load i8, i8* %str
; CHECK: %1 = zext i8 %strcmpload to i32
; CHECK: ret i32 %1
%str2 = getelementptr inbounds [1 x i8], [1 x i8]* @null, i32 0, i32 0
%temp1 = call i32 @strcmp(i8* %str1, i8* %str2)
ret i32 %temp1
}
; strcmp(x, y) -> cnst
define i32 @test3() {
; CHECK-LABEL: @test3(
; CHECK: ret i32 -1
%str1 = getelementptr inbounds [5 x i8], [5 x i8]* @hell, i32 0, i32 0
%str2 = getelementptr inbounds [6 x i8], [6 x i8]* @hello, i32 0, i32 0
%temp1 = call i32 @strcmp(i8* %str1, i8* %str2)
ret i32 %temp1
}
define i32 @test4() {
; CHECK-LABEL: @test4(
; CHECK: ret i32 1
%str1 = getelementptr inbounds [5 x i8], [5 x i8]* @hell, i32 0, i32 0
%str2 = getelementptr inbounds [1 x i8], [1 x i8]* @null, i32 0, i32 0
%temp1 = call i32 @strcmp(i8* %str1, i8* %str2)
ret i32 %temp1
}
; strcmp(x, y) -> memcmp(x, y, <known length>)
; (This transform is rather difficult to trigger in a useful manner)
define i32 @test5(i1 %b) {
; CHECK-LABEL: @test5(
; CHECK: %memcmp = call i32 @memcmp(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @hello, i32 0, i32 0), i8* %str2, i32 5)
; CHECK: ret i32 %memcmp
%str1 = getelementptr inbounds [6 x i8], [6 x i8]* @hello, i32 0, i32 0
%temp1 = getelementptr inbounds [5 x i8], [5 x i8]* @hell, i32 0, i32 0
%temp2 = getelementptr inbounds [5 x i8], [5 x i8]* @bell, i32 0, i32 0
%str2 = select i1 %b, i8* %temp1, i8* %temp2
%temp3 = call i32 @strcmp(i8* %str1, i8* %str2)
ret i32 %temp3
}
; strcmp(x,x) -> 0
define i32 @test6(i8* %str) {
; CHECK-LABEL: @test6(
; CHECK: ret i32 0
%temp1 = call i32 @strcmp(i8* %str, i8* %str)
ret i32 %temp1
}
; strcmp(x, y) == 0 -> bcmp(x, y, <known length>)
define i1 @test7(i1 %b) {
; BCMP-LABEL: @test7(
; BCMP: %bcmp = call i32 @bcmp(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @hello, i32 0, i32 0), i8* %str2, i32 5)
; BCMP: %res = icmp eq i32 %bcmp, 0
; BCMP: ret i1 %res
; NOBCMP-LABEL: @test7(
; NOBCMP: %memcmp = call i32 @memcmp(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @hello, i32 0, i32 0), i8* %str2, i32 5)
; NOBCMP: %res = icmp eq i32 %memcmp, 0
; NOBCMP: ret i1 %res
%str1 = getelementptr inbounds [6 x i8], [6 x i8]* @hello, i32 0, i32 0
%temp1 = getelementptr inbounds [5 x i8], [5 x i8]* @hell, i32 0, i32 0
%temp2 = getelementptr inbounds [5 x i8], [5 x i8]* @bell, i32 0, i32 0
%str2 = select i1 %b, i8* %temp1, i8* %temp2
%temp3 = call i32 @strcmp(i8* %str1, i8* %str2)
%res = icmp eq i32 %temp3, 0
ret i1 %res
}
|
