1; Test dwarf codegen of DW_OP_minus. 2; RUN: llc -O0 -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s 3 4; This was built by compiling the following source with SafeStack and 5; simplifying the result a little. 6; extern "C" { 7; void Capture(int *); 8; void f() { 9; int buf[100]; 10; Capture(buf); 11; } 12; } 13; The interesting part is !DIExpression(DW_OP_deref, DW_OP_minus, 400) 14 15target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" 16target triple = "x86_64-unknown-linux-gnu" 17 18@__safestack_unsafe_stack_ptr = external thread_local(initialexec) global i8* 19 20define void @f() !dbg !4 { 21entry: 22 %unsafe_stack_ptr = load i8*, i8** @__safestack_unsafe_stack_ptr 23 %unsafe_stack_static_top = getelementptr i8, i8* %unsafe_stack_ptr, i32 -400 24 store i8* %unsafe_stack_static_top, i8** @__safestack_unsafe_stack_ptr 25 %0 = getelementptr i8, i8* %unsafe_stack_ptr, i32 -400 26 %buf = bitcast i8* %0 to [100 x i32]* 27 %1 = bitcast [100 x i32]* %buf to i8*, !dbg !16 28 call void @llvm.dbg.declare(metadata i8* %unsafe_stack_ptr, metadata !8, metadata !17), !dbg !18 29 %arraydecay = getelementptr inbounds [100 x i32], [100 x i32]* %buf, i64 0, i64 0, !dbg !19 30 call void @Capture(i32* %arraydecay), !dbg !20 31 store i8* %unsafe_stack_ptr, i8** @__safestack_unsafe_stack_ptr, !dbg !21 32 ret void, !dbg !21 33} 34 35; Function Attrs: nounwind readnone 36declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone 37 38declare void @Capture(i32*) 39 40!llvm.dbg.cu = !{!0} 41!llvm.module.flags = !{!13, !14} 42 43!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.8.0 (trunk 248518) (llvm/trunk 248512)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2) 44!1 = !DIFile(filename: "1.cc", directory: "/tmp") 45!2 = !{} 46!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 4, type: !5, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !7) 47!5 = !DISubroutineType(types: !6) 48!6 = !{null} 49!7 = !{!8} 50!8 = !DILocalVariable(name: "buf", scope: !4, file: !1, line: 5, type: !9) 51!9 = !DICompositeType(tag: DW_TAG_array_type, baseType: !10, size: 3200, align: 32, elements: !11) 52!10 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed) 53!11 = !{!12} 54!12 = !DISubrange(count: 100) 55!13 = !{i32 2, !"Dwarf Version", i32 4} 56!14 = !{i32 2, !"Debug Info Version", i32 3} 57!15 = !{!"clang version 3.8.0 (trunk 248518) (llvm/trunk 248512)"} 58!16 = !DILocation(line: 5, column: 3, scope: !4) 59!17 = !DIExpression(DW_OP_deref, DW_OP_minus, 400) 60!18 = !DILocation(line: 5, column: 7, scope: !4) 61!19 = !DILocation(line: 6, column: 11, scope: !4) 62!20 = !DILocation(line: 6, column: 3, scope: !4) 63!21 = !DILocation(line: 7, column: 1, scope: !4) 64 65; RCX - 400 66; CHECK: .short 6 # Loc expr size 67; CHECK-NEXT: .byte 114 # DW_OP_breg2 68; CHECK-NEXT: .byte 0 # 0 69; CHECK-NEXT: .byte 16 # DW_OP_constu 70; CHECK-NEXT: .byte 144 # 400 71; CHECK-NEXT: .byte 3 # DW_OP_minus 72; CHECK-NEXT: .byte 28 73 74; RCX is clobbered in call @Capture, but there is a spilled copy. 75; *(RSP + 8) - 400 76; CHECK: .short 7 # Loc expr size 77; CHECK-NEXT: .byte 119 # DW_OP_breg7 78; CHECK-NEXT: .byte 8 # 8 79; CHECK-NEXT: .byte 6 # DW_OP_deref 80; CHECK-NEXT: .byte 16 # DW_OP_constu 81; CHECK-NEXT: .byte 144 # 400 82; CHECK-NEXT: .byte 3 # DW_OP_minus 83; CHECK-NEXT: .byte 28 84