xref: /llvm-project/llvm/test/CodeGen/BPF/preserve-static-offset/load-unroll.ll (revision 29441e4f5fa5f5c7709f7cf180815ba97f611297)
1; RUN: opt -O2 -mtriple=bpf-pc-linux -S -o - %s | FileCheck %s
2;
3; Check position of bpf-preserve-static-offset pass in the pipeline:
4; preserve.static.offset call should be preserved long enough to allow
5; introduction of getelementptr.and.load after loops unrolling.
6;
7; Source:
8;    #define __ctx __attribute__((preserve_static_offset))
9;
10;    struct foo {
11;      int a;
12;      int b[4];
13;    } __ctx;
14;
15;    extern void consume(int);
16;
17;    void bar(struct foo *p){
18;      unsigned long i = 0;
19;    #pragma clang loop unroll(full)
20;      while (i < 2)
21;        consume(p->b[i++]);
22;    }
23;
24; Compilation flag:
25;   clang -cc1 -O2 -triple bpf -S -emit-llvm -disable-llvm-passes -o - \
26;       | opt -passes=function(sroa) -S -o -
27
28%struct.foo = type { i32, [4 x i32] }
29
30; Function Attrs: nounwind
31define dso_local void @bar(ptr noundef %p) #0 {
32entry:
33  br label %while.cond
34
35while.cond:                                       ; preds = %while.body, %entry
36  %i.0 = phi i64 [ 0, %entry ], [ %inc, %while.body ]
37  %cmp = icmp ult i64 %i.0, 2
38  br i1 %cmp, label %while.body, label %while.end
39
40while.body:                                       ; preds = %while.cond
41  %0 = call ptr @llvm.preserve.static.offset(ptr %p)
42  %b = getelementptr inbounds %struct.foo, ptr %0, i32 0, i32 1
43  %inc = add i64 %i.0, 1
44  %arrayidx = getelementptr inbounds [4 x i32], ptr %b, i64 0, i64 %i.0
45  %1 = load i32, ptr %arrayidx, align 4, !tbaa !2
46  call void @consume(i32 noundef %1)
47  br label %while.cond, !llvm.loop !6
48
49while.end:                                        ; preds = %while.cond
50  ret void
51}
52
53; CHECK:      define dso_local void @bar(ptr noundef readonly captures(none) %[[p:.*]])
54; CHECK:        %[[v1:.*]] = tail call i32 (ptr, i1, i8, i8, i8, i1, ...)
55; CHECK-SAME:     @llvm.bpf.getelementptr.and.load.i32
56; CHECK-SAME:       (ptr readonly elementtype(i8) %[[p]],
57; CHECK-SAME:        i1 false, i8 0, i8 1, i8 2, i1 true, i64 immarg 4)
58; CHECK-SAME:      #[[attrs:.*]], !tbaa
59; CHECK-NEXT:   tail call void @consume(i32 noundef %[[v1]])
60; CHECK-NEXT:   %[[v2:.*]] = tail call i32 (ptr, i1, i8, i8, i8, i1, ...)
61; CHECK-SAME:     @llvm.bpf.getelementptr.and.load.i32
62; CHECK-SAME:       (ptr readonly elementtype(i8) %[[p]],
63; CHECK-SAME:        i1 false, i8 0, i8 1, i8 2, i1 true, i64 immarg 8)
64; CHECK-SAME:      #[[attrs]], !tbaa
65; CHECK-NEXT:   tail call void @consume(i32 noundef %[[v2]])
66; CHECK:      attributes #[[attrs]] = { memory(argmem: read) }
67
68; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
69declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1
70
71declare void @consume(i32 noundef) #2
72
73; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
74declare ptr @llvm.preserve.static.offset(ptr readnone) #3
75
76; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
77declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1
78
79attributes #0 = { nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
80attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
81attributes #2 = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
82attributes #3 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
83
84!llvm.module.flags = !{!0}
85!llvm.ident = !{!1}
86
87!0 = !{i32 1, !"wchar_size", i32 4}
88!1 = !{!"clang"}
89!2 = !{!3, !3, i64 0}
90!3 = !{!"int", !4, i64 0}
91!4 = !{!"omnipotent char", !5, i64 0}
92!5 = !{!"Simple C/C++ TBAA"}
93!6 = distinct !{!6, !7, !8}
94!7 = !{!"llvm.loop.mustprogress"}
95!8 = !{!"llvm.loop.unroll.full"}
96