--- | ; RUN: llc -run-pass=machinelicm -o - %s | FileCheck %s ; Line numbers should not be retained when loop invariant instructions are hoisted. ; Doing so causes poor stepping bevavior. ; ; Created from: ; int x; ; void Process(const unsigned int *p) ; { ; while (1) ; x = *p++; ; } ; ; with clang -emit-llvm -S -O2 -g -o t.ll t.c ; llc -relocation-model=pic -stop-after=machine-combine -O2 t.ll -o t.mir ; ; We check that when the machine loop invariant pass hoists instructions ; out of a loop the debug information is not retained. ; ; CHECK-LABEL: bb.0.entry: ; CHECK: MOV64rm $rip, 1, $noreg, target-flags(x86-gotpcrel) @x, $noreg :: (load 8 from got) ; CHECK-LABEL: bb.1.while.body: ; ; ModuleID = 'tx.ll' source_filename = "t.c" target triple = "x86_64-unknown-linux-gnu" @x = common local_unnamed_addr global i32 0, align 4, !dbg !0 ; Function Attrs: noreturn nounwind uwtable define void @Process(i32* nocapture readonly %p) local_unnamed_addr !dbg !9 { entry: tail call void @llvm.dbg.value(metadata i32* %p, i64 0, metadata !16, metadata !17), !dbg !18 br label %while.body, !dbg !19 while.body: ; preds = %while.body, %entry %p.addr.0 = phi i32* [ %p, %entry ], [ %incdec.ptr, %while.body ] tail call void @llvm.dbg.value(metadata i32* %p.addr.0, i64 0, metadata !16, metadata !17), !dbg !18 %incdec.ptr = getelementptr inbounds i32, i32* %p.addr.0, i64 1, !dbg !20 tail call void @llvm.dbg.value(metadata i32* %incdec.ptr, i64 0, metadata !16, metadata !17), !dbg !18 %0 = load i32, i32* %p.addr.0, align 4, !dbg !21, !tbaa !22 store i32 %0, i32* @x, align 4, !dbg !26, !tbaa !22 br label %while.body, !dbg !27, !llvm.loop !29 } ; Function Attrs: nounwind readnone declare void @llvm.dbg.value(metadata, i64, metadata, metadata) !llvm.dbg.cu = !{!1} !llvm.module.flags = !{!6, !7} !llvm.ident = !{!8} !0 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "x", scope: !1, file: !2, line: 1, type: !5, isLocal: false, isDefinition: true), expr: !DIExpression()) !1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, producer: "clang version 4.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !3, globals: !4) !2 = !DIFile(filename: "t.c", directory: "/home/test") !3 = !{} !4 = !{!0} !5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed) !6 = !{i32 2, !"Dwarf Version", i32 4} !7 = !{i32 2, !"Debug Info Version", i32 3} !8 = !{!"clang version 4.0.0 "} !9 = distinct !DISubprogram(name: "Process", scope: !2, file: !2, line: 2, type: !10, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: true, unit: !1, retainedNodes: !15) !10 = !DISubroutineType(types: !11) !11 = !{null, !12} !12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !13, size: 64) !13 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !14) !14 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned) !15 = !{!16} !16 = !DILocalVariable(name: "p", arg: 1, scope: !9, file: !2, line: 2, type: !12) !17 = !DIExpression() !18 = !DILocation(line: 2, column: 34, scope: !9) !19 = !DILocation(line: 4, column: 3, scope: !9) !20 = !DILocation(line: 5, column: 11, scope: !9) !21 = !DILocation(line: 5, column: 9, scope: !9) !22 = !{!23, !23, i64 0} !23 = !{!"int", !24, i64 0} !24 = !{!"omnipotent char", !25, i64 0} !25 = !{!"C++"} !26 = !DILocation(line: 5, column: 7, scope: !9) !27 = !DILocation(line: 4, column: 3, scope: !28) !28 = !DILexicalBlockFile(scope: !9, file: !2, discriminator: 1) !29 = distinct !{!29, !19, !20} ... --- name: Process tracksRegLiveness: true registers: - { id: 0, class: gr64 } - { id: 1, class: gr64 } - { id: 2, class: gr64 } - { id: 3, class: gr32 } - { id: 4, class: gr64 } body: | bb.0.entry: successors: %bb.1.while.body(0x80000000) liveins: $rdi DBG_VALUE $rdi, _, !16, !17, debug-location !18 %2 = COPY $rdi DBG_VALUE %2, _, !16, !17, debug-location !18 bb.1.while.body: successors: %bb.1.while.body(0x80000000) %0 = PHI %2, %bb.0.entry, %1, %bb.1.while.body DBG_VALUE %0, _, !16, !17, debug-location !18 %1 = ADD64ri8 %0, 4, implicit-def dead $eflags, debug-location !20 DBG_VALUE %1, _, !16, !17, debug-location !18 %3 = MOV32rm %0, 1, _, 0, _, debug-location !21 :: (load 4 from %ir.p.addr.0, !tbaa !22) %4 = MOV64rm $rip, 1, _, target-flags(x86-gotpcrel) @x, _, debug-location !26 :: (load 8 from got) MOV32mr killed %4, 1, _, 0, _, killed %3, debug-location !26 :: (store 4 into @x, !tbaa !22) JMP_1 %bb.1.while.body, debug-location !27 ...