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 chain of GEP instructions. 4; 5; Source: 6; #define __ctx __attribute__((preserve_static_offset)) 7; 8; struct foo { 9; int a[2]; 10; }; 11; 12; struct bar { 13; int a; 14; struct foo b; 15; } __ctx; 16; 17; extern void consume(int); 18; 19; void buz(struct bar *p) { 20; consume(p->b.a[1]); 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%struct.bar = type { i32, %struct.foo } 28%struct.foo = type { [2 x i32] } 29 30; Function Attrs: nounwind 31define dso_local void @buz(ptr noundef %p) #0 { 32entry: 33 %0 = call ptr @llvm.preserve.static.offset(ptr %p) 34 %b = getelementptr inbounds %struct.bar, ptr %0, i32 0, i32 1 35 %a = getelementptr inbounds %struct.foo, ptr %b, i32 0, i32 0 36 %arrayidx = getelementptr inbounds [2 x i32], ptr %a, i64 0, i64 1 37 %1 = load i32, ptr %arrayidx, align 4, !tbaa !2 38 call void @consume(i32 noundef %1) 39 ret void 40} 41 42; CHECK: %[[v1:.*]] = call i32 (ptr, i1, i8, i8, i8, i1, ...) 43; CHECK-SAME: @llvm.bpf.getelementptr.and.load.i32 44; CHECK-SAME: (ptr readonly elementtype(%struct.bar) %{{[^,]+}}, 45; CHECK-SAME: i1 false, i8 0, i8 1, i8 2, i1 true, 46; CHECK-SAME: i32 immarg 0, i32 immarg 1, i32 immarg 0, i64 immarg 1) 47; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 48; folded gep chain 49; CHECK-NEXT: call void @consume(i32 noundef %[[v1]]) 50 51declare void @consume(i32 noundef) #1 52 53; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none) 54declare ptr @llvm.preserve.static.offset(ptr readnone) #2 55 56attributes #0 = { nounwind "no-trapping-math"="true" "stack-protector-buffer-size"="8" } 57attributes #1 = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" } 58attributes #2 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) } 59 60!llvm.module.flags = !{!0} 61!llvm.ident = !{!1} 62 63!0 = !{i32 1, !"wchar_size", i32 4} 64!1 = !{!"clang"} 65!2 = !{!3, !3, i64 0} 66!3 = !{!"int", !4, i64 0} 67!4 = !{!"omnipotent char", !5, i64 0} 68!5 = !{!"Simple C/C++ TBAA"} 69