xref: /llvm-project/llvm/test/CodeGen/BPF/vla.ll (revision 2a61ceddb30aaed291317795e3183371e8cf3d7a)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -passes=bpf-ir-peephole -mtriple=bpf-pc-linux -S %s | FileCheck %s
3; Source:
4;   #define AA 40
5;   struct t {
6;     char a[20];
7;   };
8;   void foo(ptr);
9;
10;   int test1() {
11;     const int a = 8;
12;     char tmp[AA + sizeof(struct t) + a];
13;     foo(tmp);
14;     return 0;
15;   }
16;
17;   int test2(int b) {
18;     const int a = 8;
19;     char tmp[a + b];
20;     foo(tmp);
21;     return 0;
22;   }
23; Compilation flag:
24;   clang -target bpf -O2 -S -emit-llvm t.c -Xclang -disable-llvm-passes
25
26source_filename = "t.c"
27target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
28target triple = "bpf"
29
30; Function Attrs: nounwind
31define dso_local i32 @test1() {
32; CHECK-LABEL: @test1(
33; CHECK-NEXT:  entry:
34; CHECK-NEXT:    [[A:%.*]] = alloca i32, align 4
35; CHECK-NEXT:    [[SAVED_STACK:%.*]] = alloca ptr, align 8
36; CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 4, ptr [[A]])
37; CHECK-NEXT:    store i32 8, ptr [[A]], align 4
38; CHECK-NEXT:    [[VLA:%.*]] = alloca i8, i64 68, align 1
39; CHECK-NEXT:    call void @foo(ptr [[VLA]])
40; CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 4, ptr [[A]])
41; CHECK-NEXT:    ret i32 0
42;
43entry:
44  %a = alloca i32, align 4
45  %saved_stack = alloca ptr, align 8
46  call void @llvm.lifetime.start.p0(i64 4, ptr %a)
47  store i32 8, ptr %a, align 4
48  %0 = call ptr @llvm.stacksave()
49  store ptr %0, ptr %saved_stack, align 8
50  %vla = alloca i8, i64 68, align 1
51  call void @foo(ptr %vla)
52  %1 = load ptr, ptr %saved_stack, align 8
53  call void @llvm.stackrestore(ptr %1)
54  call void @llvm.lifetime.end.p0(i64 4, ptr %a)
55  ret i32 0
56}
57
58declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture)
59
60declare ptr @llvm.stacksave()
61
62declare dso_local void @foo(ptr)
63
64declare void @llvm.stackrestore(ptr)
65
66declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture)
67
68define dso_local i32 @test2(i32 %b) {
69; CHECK-LABEL: @test2(
70; CHECK-NEXT:  entry:
71; CHECK-NEXT:    [[B_ADDR:%.*]] = alloca i32, align 4
72; CHECK-NEXT:    [[A:%.*]] = alloca i32, align 4
73; CHECK-NEXT:    [[SAVED_STACK:%.*]] = alloca ptr, align 8
74; CHECK-NEXT:    [[__VLA_EXPR0:%.*]] = alloca i64, align 8
75; CHECK-NEXT:    store i32 [[B:%.*]], ptr [[B_ADDR]], align 4
76; CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 4, ptr [[A]])
77; CHECK-NEXT:    store i32 8, ptr [[A]], align 4
78; CHECK-NEXT:    [[TMP1:%.*]] = load i32, ptr [[B_ADDR]], align 4
79; CHECK-NEXT:    [[ADD:%.*]] = add nsw i32 8, [[TMP1]]
80; CHECK-NEXT:    [[TMP2:%.*]] = zext i32 [[ADD]] to i64
81; CHECK-NEXT:    [[VLA:%.*]] = alloca i8, i64 [[TMP2]], align 1
82; CHECK-NEXT:    store i64 [[TMP2]], ptr [[__VLA_EXPR0]], align 8
83; CHECK-NEXT:    call void @foo(ptr [[VLA]])
84; CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 4, ptr [[A]])
85; CHECK-NEXT:    ret i32 0
86;
87entry:
88  %b.addr = alloca i32, align 4
89  %a = alloca i32, align 4
90  %saved_stack = alloca ptr, align 8
91  %__vla_expr0 = alloca i64, align 8
92  store i32 %b, ptr %b.addr, align 4
93  call void @llvm.lifetime.start.p0(i64 4, ptr %a)
94  store i32 8, ptr %a, align 4
95  %0 = load i32, ptr %b.addr, align 4
96  %add = add nsw i32 8, %0
97  %1 = zext i32 %add to i64
98  %2 = call ptr @llvm.stacksave()
99  store ptr %2, ptr %saved_stack, align 8
100  %vla = alloca i8, i64 %1, align 1
101  store i64 %1, ptr %__vla_expr0, align 8
102  call void @foo(ptr %vla)
103  %3 = load ptr, ptr %saved_stack, align 8
104  call void @llvm.stackrestore(ptr %3)
105  call void @llvm.lifetime.end.p0(i64 4, ptr %a)
106  ret i32 0
107}
108