1; RUN: opt -passes=bpf-preserve-static-offset -mtriple=bpf-pc-linux -S -o - %s | FileCheck %s 2; 3; Check that bpf-preserve-static-offset folds GEP chains that end by 4; getelementptr.and.store. 5; 6; Source (modified by hand): 7; #define __ctx __attribute__((preserve_static_offset)) 8; 9; struct bar { 10; int aa; 11; int bb; 12; }; 13; 14; struct foo { 15; int a; 16; struct bar b; 17; } __ctx; 18; 19; void buz(struct foo *p) { 20; p->b.bb = 42; 21; } 22; 23; Compilation flag: 24; clang -cc1 -O2 -triple bpf -S -emit-llvm -disable-llvm-passes -o - \ 25; | opt -passes=function(sroa) -S -o - 26; 27; And modified to fold last getelementptr/store as a single 28; getelementptr.and.store. 29 30%struct.foo = type { i32, %struct.bar } 31%struct.bar = type { i32, i32 } 32 33; Function Attrs: nounwind 34define dso_local void @buz(ptr noundef %p) #0 { 35entry: 36 %0 = call ptr @llvm.preserve.static.offset(ptr %p) 37 %b = getelementptr inbounds %struct.foo, ptr %0, i32 0, i32 1 38 call void (i32, ptr, i1, i8, i8, i8, i1, ...) 39 @llvm.bpf.getelementptr.and.store.i32 40 (i32 42, 41 ptr writeonly elementtype(%struct.bar) %b, 42 i1 false, i8 0, i8 1, i8 2, i1 true, i32 immarg 0, i32 immarg 1) 43 #3, !tbaa !2 44 ret void 45} 46 47; CHECK: define dso_local void @buz(ptr noundef %[[p:.*]]) 48; CHECK: call void (i32, ptr, i1, i8, i8, i8, i1, ...) 49; CHECK-SAME: @llvm.bpf.getelementptr.and.store.i32 50; CHECK-SAME: (i32 42, 51; CHECK-SAME: ptr writeonly elementtype(%struct.foo) %[[p]], 52; CHECK-SAME: i1 false, i8 0, i8 1, i8 2, i1 true, i32 immarg 0, i32 immarg 1, i32 immarg 1) 53; CHECK-SAME: #[[v2:.*]], !tbaa 54; CHECK: attributes #[[v2]] = { memory(argmem: write) } 55 56; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none) 57declare ptr @llvm.preserve.static.offset(ptr readnone) #1 58 59; Function Attrs: nocallback nofree nounwind willreturn 60declare void @llvm.bpf.getelementptr.and.store.i32(i32, ptr nocapture, i1 immarg, i8 immarg, i8 immarg, i8 immarg, i1 immarg, ...) #2 61 62attributes #0 = { nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" } 63attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) } 64attributes #2 = { nocallback nofree nounwind willreturn } 65attributes #3 = { memory(argmem: write) } 66 67!llvm.module.flags = !{!0} 68!llvm.ident = !{!1} 69 70!0 = !{i32 1, !"wchar_size", i32 4} 71!1 = !{!"clang"} 72!2 = !{!3, !4, i64 8} 73!3 = !{!"foo", !4, i64 0, !7, i64 4} 74!4 = !{!"int", !5, i64 0} 75!5 = !{!"omnipotent char", !6, i64 0} 76!6 = !{!"Simple C/C++ TBAA"} 77!7 = !{!"bar", !4, i64 0, !4, i64 4} 78