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 keeps track of 'inbounds' flags while 4; folding chain of GEP instructions. 5; 6; Source (IR modified by hand): 7; #define __ctx __attribute__((preserve_static_offset)) 8; 9; struct foo { 10; int a[2]; 11; }; 12; 13; struct bar { 14; int a; 15; struct foo b; 16; } __ctx; 17; 18; extern void consume(int); 19; 20; void buz(struct bar *p) { 21; consume(p->b.a[1]); 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; Modified to remove one of the 'inbounds' from one of the GEP instructions. 29 30%struct.bar = type { i32, %struct.foo } 31%struct.foo = type { [2 x 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.bar, ptr %0, i32 0, i32 1 38 %a = getelementptr %struct.foo, ptr %b, i32 0, i32 0 39 %arrayidx = getelementptr inbounds [2 x i32], ptr %a, i64 0, i64 1 40 %1 = load i32, ptr %arrayidx, align 4, !tbaa !2 41 call void @consume(i32 noundef %1) 42 ret void 43} 44 45; CHECK: %[[v1:.*]] = call i32 (ptr, i1, i8, i8, i8, i1, ...) 46; CHECK-SAME: @llvm.bpf.getelementptr.and.load.i32 47; CHECK-SAME: (ptr readonly elementtype(%struct.bar) %{{[^,]+}}, 48; CHECK-SAME: i1 false, i8 0, i8 1, i8 2, i1 false, 49; ^^^^^^^^ 50; not inbounds 51; CHECK-SAME: i32 immarg 0, i32 immarg 1, i32 immarg 0, i64 immarg 1) 52; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 53; folded gep chain 54; CHECK-NEXT: call void @consume(i32 noundef %[[v1]]) 55 56declare void @consume(i32 noundef) #1 57 58; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none) 59declare ptr @llvm.preserve.static.offset(ptr readnone) #2 60 61attributes #0 = { nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" } 62attributes #1 = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" } 63attributes #2 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) } 64 65!llvm.module.flags = !{!0} 66!llvm.ident = !{!1} 67 68!0 = !{i32 1, !"wchar_size", i32 4} 69!1 = !{!"clang"} 70!2 = !{!3, !3, i64 0} 71!3 = !{!"int", !4, i64 0} 72!4 = !{!"omnipotent char", !5, i64 0} 73!5 = !{!"Simple C/C++ TBAA"} 74