1; RUN: opt -O2 -mtriple=bpf-pc-linux -S -o - %s | FileCheck %s 2; 3; Check that stores from zero offset are not modified by bpf-preserve-static-offset. 4; 5; Source: 6; #define __ctx __attribute__((preserve_static_offset)) 7; 8; struct foo { 9; int a; 10; } __ctx; 11; 12; void bar(struct foo *p) { 13; p->a = 0; 14; } 15; 16; Compilation flag: 17; clang -cc1 -O2 -triple bpf -S -emit-llvm -disable-llvm-passes -o - \ 18; | opt -passes=function(sroa) -S -o - 19 20%struct.foo = type { i32 } 21 22; Function Attrs: nounwind 23define dso_local void @bar(ptr noundef %p) #0 { 24entry: 25 %0 = call ptr @llvm.preserve.static.offset(ptr %p) 26 %a = getelementptr inbounds %struct.foo, ptr %0, i32 0, i32 0 27 store i32 0, ptr %a, align 4, !tbaa !2 28 ret void 29} 30 31; CHECK: define dso_local void @bar(ptr noundef writeonly captures(none) initializes((0, 4)) %[[p:.*]]) 32; CHECK-NEXT: entry: 33; CHECK-NEXT: store i32 0, ptr %[[p]], align 4, !tbaa 34; CHECK-NEXT: ret void 35 36; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none) 37declare ptr @llvm.preserve.static.offset(ptr readnone) #1 38 39attributes #0 = { nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" } 40attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) } 41 42!llvm.module.flags = !{!0} 43!llvm.ident = !{!1} 44 45!0 = !{i32 1, !"wchar_size", i32 4} 46!1 = !{!"clang"} 47!2 = !{!3, !4, i64 0} 48!3 = !{!"foo", !4, i64 0} 49!4 = !{!"int", !5, i64 0} 50!5 = !{!"omnipotent char", !6, i64 0} 51!6 = !{!"Simple C/C++ TBAA"} 52