llvm/test/CodeGen/BPF/preserve-static-offset/load-atomic.ll

; RUN: opt -passes=bpf-preserve-static-offset -mtriple=bpf-pc-linux -S -o - %s | FileCheck %s
;
; Check handling of atomic load instruction by bpf-preserve-static-offset.
;
; Source:
;    #define __ctx __attribute__((preserve_static_offset))
;    
;    struct foo {
;      int _;
;      int a;
;    } __ctx;
;    
;    extern void consume(int);
;    
;    void bar(struct foo *p) {
;      int r;
;      __atomic_load(&p->a, &r, 2);
;      consume(r);
;    }
;
; Compilation flag:
;   clang -cc1 -O2 -triple bpf -S -emit-llvm -disable-llvm-passes -o - \
;       | opt -passes=function(sroa) -S -o -

%struct.foo = type { i32, i32 }

; Function Attrs: nounwind
define dso_local void @bar(ptr noundef %p) #0 {
entry:
  %0 = call ptr @llvm.preserve.static.offset(ptr %p)
  %a = getelementptr inbounds %struct.foo, ptr %0, i32 0, i32 1
  %1 = load atomic i32, ptr %a acquire, align 4
  call void @consume(i32 noundef %1)
  ret void
}

; CHECK:      %[[a1:.*]] = call i32 (ptr, i1, i8, i8, i8, i1, ...)
; CHECK-SAME:    @llvm.bpf.getelementptr.and.load.i32
; CHECK-SAME:      (ptr elementtype(%struct.foo) %[[p:.*]],
;                   i1 false, i8 4, i8 1, i8 2, i1 true, i32 immarg 0, i32 immarg 1)
;                             ^^^^
;                          atomic order
; CHECK-NOT:  #{{[0-9]+}}
; CHECK-NEXT: call void @consume(i32 noundef %[[a1]])

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare ptr @llvm.preserve.static.offset(ptr readnone) #2

declare void @consume(i32 noundef) #3

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
attributes #3 = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" }

!llvm.module.flags = !{!0}
!llvm.ident = !{!1}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{!"clang"}