xref: /llvm-project/llvm/test/Transforms/InstCombine/memcmp-1.ll (revision 4ab40eca080965c65802710e39adbb78c4ce7bde)
1; Test that the memcmp library call simplifier works correctly.
2;
3; RUN: opt < %s -passes=instcombine -S | FileCheck --check-prefix=CHECK --check-prefix=NOBCMP %s
4; RUN: opt < %s -passes=instcombine -mtriple=x86_64-unknown-linux-gnu -S | FileCheck --check-prefix=CHECK --check-prefix=BCMP %s
5
6target 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-n8:16:32:64"
7
8@foo = constant [4 x i8] c"foo\00"
9@hel = constant [4 x i8] c"hel\00"
10@hello_u = constant [8 x i8] c"hello_u\00"
11
12declare i32 @memcmp(ptr, ptr, i32)
13
14; Check memcmp(mem, mem, size) -> 0.
15
16define i32 @test_simplify1(ptr %mem, i32 %size) {
17; CHECK-LABEL: @test_simplify1(
18; CHECK-NEXT:    ret i32 0
19;
20  %ret = call i32 @memcmp(ptr %mem, ptr %mem, i32 %size)
21  ret i32 %ret
22}
23
24; Check memcmp(mem1, mem2, 0) -> 0.
25
26define i32 @test_simplify2(ptr %mem1, ptr %mem2) {
27; CHECK-LABEL: @test_simplify2(
28; CHECK-NEXT:    ret i32 0
29;
30  %ret = call i32 @memcmp(ptr %mem1, ptr %mem2, i32 0)
31  ret i32 %ret
32}
33
34;; Check memcmp(mem1, mem2, 1) -> *(unsigned char*)mem1 - *(unsigned char*)mem2.
35
36define i32 @test_simplify3(ptr %mem1, ptr %mem2) {
37; CHECK-LABEL: @test_simplify3(
38; CHECK-NEXT:    [[LHSC:%.*]] = load i8, ptr %mem1, align 1
39; CHECK-NEXT:    [[LHSV:%.*]] = zext i8 [[LHSC]] to i32
40; CHECK-NEXT:    [[RHSC:%.*]] = load i8, ptr %mem2, align 1
41; CHECK-NEXT:    [[RHSV:%.*]] = zext i8 [[RHSC]] to i32
42; CHECK-NEXT:    [[CHARDIFF:%.*]] = sub nsw i32 [[LHSV]], [[RHSV]]
43; CHECK-NEXT:    ret i32 [[CHARDIFF]]
44;
45  %ret = call i32 @memcmp(ptr %mem1, ptr %mem2, i32 1)
46  ret i32 %ret
47}
48
49; Check memcmp(mem1, mem2, size) -> cnst, where all arguments are constants.
50
51define i32 @test_simplify4() {
52; CHECK-LABEL: @test_simplify4(
53; CHECK-NEXT:    ret i32 0
54;
55  %ret = call i32 @memcmp(ptr @hel, ptr @hello_u, i32 3)
56  ret i32 %ret
57}
58
59define i32 @test_simplify5() {
60; CHECK-LABEL: @test_simplify5(
61; CHECK-NEXT:    ret i32 1
62;
63  %ret = call i32 @memcmp(ptr @hel, ptr @foo, i32 3)
64  ret i32 %ret
65}
66
67define i32 @test_simplify6() {
68; CHECK-LABEL: @test_simplify6(
69; CHECK-NEXT:    ret i32 -1
70;
71  %ret = call i32 @memcmp(ptr @foo, ptr @hel, i32 3)
72  ret i32 %ret
73}
74
75; Check memcmp(mem1, mem2, 8)==0 -> *(int64_t*)mem1 == *(int64_t*)mem2
76
77define i1 @test_simplify7(i64 %x, i64 %y) {
78; CHECK-LABEL: @test_simplify7(
79; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i64 %x, %y
80; CHECK-NEXT:    ret i1 [[CMP]]
81;
82  %x.addr = alloca i64, align 8
83  %y.addr = alloca i64, align 8
84  store i64 %x, ptr %x.addr, align 8
85  store i64 %y, ptr %y.addr, align 8
86  %call = call i32 @memcmp(ptr %x.addr, ptr %y.addr, i32 8)
87  %cmp = icmp eq i32 %call, 0
88  ret i1 %cmp
89}
90
91; Check memcmp(mem1, mem2, 4)==0 -> *(int32_t*)mem1 == *(int32_t*)mem2
92
93define i1 @test_simplify8(i32 %x, i32 %y) {
94; CHECK-LABEL: @test_simplify8(
95; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 %x, %y
96; CHECK-NEXT:    ret i1 [[CMP]]
97;
98  %x.addr = alloca i32, align 4
99  %y.addr = alloca i32, align 4
100  store i32 %x, ptr %x.addr, align 4
101  store i32 %y, ptr %y.addr, align 4
102  %call = call i32 @memcmp(ptr %x.addr, ptr %y.addr, i32 4)
103  %cmp = icmp eq i32 %call, 0
104  ret i1 %cmp
105}
106
107; Check memcmp(mem1, mem2, 2)==0 -> *(int16_t*)mem1 == *(int16_t*)mem2
108
109define i1 @test_simplify9(i16 %x, i16 %y) {
110; CHECK-LABEL: @test_simplify9(
111; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i16 %x, %y
112; CHECK-NEXT:    ret i1 [[CMP]]
113;
114  %x.addr = alloca i16, align 2
115  %y.addr = alloca i16, align 2
116  store i16 %x, ptr %x.addr, align 2
117  store i16 %y, ptr %y.addr, align 2
118  %call = call i32 @memcmp(ptr %x.addr, ptr %y.addr, i32 2)
119  %cmp = icmp eq i32 %call, 0
120  ret i1 %cmp
121}
122
123; Check memcmp(mem1, mem2, size)==0 -> bcmp(mem1, mem2, size)==0
124
125define i1 @test_simplify10(ptr %mem1, ptr %mem2, i32 %size) {
126; NOBCMP-LABEL: @test_simplify10(
127; NOBCMP-NEXT:    [[CALL:%.*]] = call i32 @memcmp(ptr %mem1, ptr %mem2, i32 %size)
128; NOBCMP-NEXT:    [[CMP:%.*]] = icmp eq i32 [[CALL]], 0
129; NOBCMP-NEXT:    ret i1 [[CMP]]
130;
131; BCMP-LABEL: @test_simplify10(
132; BCMP-NEXT:    [[CALL:%.*]] = call i32 @bcmp(ptr %mem1, ptr %mem2, i32 %size)
133; BCMP-NEXT:    [[CMP:%.*]] = icmp eq i32 [[CALL]], 0
134; BCMP-NEXT:    ret i1 [[CMP]]
135;
136  %call = call i32 @memcmp(ptr %mem1, ptr %mem2, i32 %size)
137  %cmp = icmp eq i32 %call, 0
138  ret i1 %cmp
139}
140