xref: /llvm-project/llvm/test/Transforms/InstCombine/strlen-9.ll (revision 90ba33099cbb17e7c159e9ebc5a512037db99d6d)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2;
3; Verify that strlen calls with unterminated constant arrays or with
4; just past-the-end pointers to strings are not folded.
5;
6; RUN: opt < %s -passes=instcombine -S | FileCheck %s
7
8declare i64 @strlen(ptr)
9
10@a5 = constant [5 x i8] c"12345"
11@s5 = constant [6 x i8] c"12345\00"
12@z0 = constant [0 x i8] zeroinitializer
13@z5 = constant [5 x i8] zeroinitializer
14
15
16; Verify that all the invalid calls below are folded.  This is safer than
17; making the library calls even though it prevents sanitizers from reporting
18; the bugs.
19
20define void @fold_strlen_no_nul(ptr %plen, i32 %i) {
21; CHECK-LABEL: @fold_strlen_no_nul(
22; CHECK-NEXT:    store i64 5, ptr [[PLEN:%.*]], align 4
23; CHECK-NEXT:    [[PNA5_P5:%.*]] = getelementptr i8, ptr [[PLEN]], i64 8
24; CHECK-NEXT:    store i64 0, ptr [[PNA5_P5]], align 4
25; CHECK-NEXT:    [[PNS5_P6:%.*]] = getelementptr i8, ptr [[PLEN]], i64 16
26; CHECK-NEXT:    store i64 0, ptr [[PNS5_P6]], align 4
27; CHECK-NEXT:    [[TMP1:%.*]] = sext i32 [[I:%.*]] to i64
28; CHECK-NEXT:    [[PA5_PI:%.*]] = getelementptr [5 x i8], ptr @a5, i64 0, i64 [[TMP1]]
29; CHECK-NEXT:    [[NA5_PI:%.*]] = call i64 @strlen(ptr noundef nonnull dereferenceable(1) [[PA5_PI]])
30; CHECK-NEXT:    [[PNA5_PI:%.*]] = getelementptr i8, ptr [[PLEN]], i64 24
31; CHECK-NEXT:    store i64 [[NA5_PI]], ptr [[PNA5_PI]], align 4
32; CHECK-NEXT:    [[PNZ0_P0:%.*]] = getelementptr i8, ptr [[PLEN]], i64 32
33; CHECK-NEXT:    store i64 0, ptr [[PNZ0_P0]], align 4
34; CHECK-NEXT:    [[TMP2:%.*]] = sext i32 [[I]] to i64
35; CHECK-NEXT:    [[PZ0_PI:%.*]] = getelementptr [0 x i8], ptr @z0, i64 0, i64 [[TMP2]]
36; CHECK-NEXT:    [[NZ0_PI:%.*]] = call i64 @strlen(ptr noundef nonnull dereferenceable(1) [[PZ0_PI]])
37; CHECK-NEXT:    [[PNZ0_PI:%.*]] = getelementptr i8, ptr [[PLEN]], i64 40
38; CHECK-NEXT:    store i64 [[NZ0_PI]], ptr [[PNZ0_PI]], align 4
39; CHECK-NEXT:    [[PNZ5_P5:%.*]] = getelementptr i8, ptr [[PLEN]], i64 48
40; CHECK-NEXT:    store i64 0, ptr [[PNZ5_P5]], align 4
41; CHECK-NEXT:    ret void
42;
43; Verify that strlen(a5) is folded to 5.
44  %na5_p0 = call i64 @strlen(ptr @a5)
45  store i64 %na5_p0, ptr %plen
46
47; Verify that strlen(a5 + 5) is folded to 0.
48  %pa5_p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
49  %na5_p5 = call i64 @strlen(ptr %pa5_p5)
50  %pna5_p5 = getelementptr i64, ptr %plen, i64 1
51  store i64 %na5_p5, ptr %pna5_p5
52
53; Verify that strlen(s5 + 6) is folded to 0.
54  %ps5_p6 = getelementptr [6 x i8], ptr @s5, i32 0, i32 6
55  %ns5_p6 = call i64 @strlen(ptr %ps5_p6)
56  %pns5_p6 = getelementptr i64, ptr %plen, i64 2
57  store i64 %ns5_p6, ptr %pns5_p6
58
59; TODO: Verify that strlen(a5 + i) is folded to 5 - i?  It's currently
60; not folded because the variable offset makes getConstantDataArrayInfo
61; fail.
62  %pa5_pi = getelementptr [5 x i8], ptr @a5, i32 0, i32 %i
63  %na5_pi = call i64 @strlen(ptr %pa5_pi)
64  %pna5_pi = getelementptr i64, ptr %plen, i64 3
65  store i64 %na5_pi, ptr %pna5_pi
66
67; Verify that strlen(z0) is folded to 0.
68  %nz0_p0 = call i64 @strlen(ptr @z0)
69  %pnz0_p0 = getelementptr i64, ptr %plen, i64 4
70  store i64 %nz0_p0, ptr %pnz0_p0
71
72; TODO: Verify that strlen(z0 + i) is folded to 0.  As the case above,
73; this one is not folded either because the variable offset makes
74; getConstantDataArrayInfo fail.
75
76  %pz0_pi = getelementptr [0 x i8], ptr @z0, i32 0, i32 %i
77  %nz0_pi = call i64 @strlen(ptr %pz0_pi)
78  %pnz0_pi = getelementptr i64, ptr %plen, i64 5
79  store i64 %nz0_pi, ptr %pnz0_pi
80
81; Verify that strlen(z5 + 5) is folded to 0.
82  %pz5_p5 = getelementptr [5 x i8], ptr @z5, i32 0, i32 5
83  %nz5_p5 = call i64 @strlen(ptr %pz5_p5)
84  %pnz5_p5 = getelementptr i64, ptr %plen, i64 6
85  store i64 %nz5_p5, ptr %pnz5_p5
86
87  ret void
88}
89