llvm/clang/test/CodeGen/bpf-preserve-static-offset-arr.c

// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 2
// REQUIRES: bpf-registered-target
// RUN: %clang_cc1 -triple bpf -disable-llvm-passes -emit-llvm -o - %s | FileCheck %s

// Check that call to preserve.static.offset is generated when array
// member of a struct marked with __attribute__((preserve_static_offset))
// is accessed.

#define __ctx __attribute__((preserve_static_offset))

struct foo {
  struct {
    int a;
  } b[7];
} __ctx;

// CHECK-LABEL: define dso_local i32 @arr_access
// CHECK-SAME: (ptr noundef [[P:%.*]]) #[[ATTR0:[0-9]+]] {
// CHECK-NEXT:  entry:
// CHECK-NEXT:    [[P_ADDR:%.*]] = alloca ptr, align 8
// CHECK-NEXT:    store ptr [[P]], ptr [[P_ADDR]], align 8
// CHECK-NEXT:    [[TMP0:%.*]] = load ptr, ptr [[P_ADDR]], align 8
// CHECK-NEXT:    [[TMP1:%.*]] = call ptr @llvm.preserve.static.offset(ptr [[TMP0]])
// CHECK-NEXT:    [[B:%.*]] = getelementptr inbounds nuw [[STRUCT_FOO:%.*]], ptr [[TMP1]], i32 0, i32 0
// CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds [7 x %struct.anon], ptr [[B]], i64 0, i64 2
// CHECK-NEXT:    [[A:%.*]] = getelementptr inbounds nuw [[STRUCT_ANON:%.*]], ptr [[ARRAYIDX]], i32 0, i32 0
// CHECK-NEXT:    [[TMP2:%.*]] = load i32, ptr [[A]], align 4
// CHECK-NEXT:    ret i32 [[TMP2]]
//
int arr_access(struct foo *p) {
  return p->b[2].a;
}