e3cd498ff7
The Assignment Tracking debug-info feature is outlined in this RFC: https://discourse.llvm.org/t/ rfc-assignment-tracking-a-better-way-of-specifying-variable-locations-in-ir The inliner requires two additions: fixupAssignments - Update inlined instructions' DIAssignID metadata so that inlined DIAssignID attachments are unique to the inlined instance. trackInlinedStores - Treat inlined stores to caller-local variables (i.e. callee stores to argument pointers that point to the caller's allocas) as assignments. Track them using trackAssignments, which is the same method as is used by the AssignmentTrackingPass. This means that we're able to detect stale memory locations due to DSE after inlining. Because the stores are only tracked _after_ inlining, any DSE or movement of stores _before_ inlining will not be accounted for. This is an accepted limitation mentioned in the RFC. One change is also required: Update CloneBlock to preserve debug use-before-defs. Otherwise the assignments will be dropped due to having the intrinsic operands replaced with empty metadata (see use-before-def.ll in this patch and this related discourse post. Reviewed By: jmorse Differential Revision: https://reviews.llvm.org/D133318
88 lines
4.2 KiB
LLVM
88 lines
4.2 KiB
LLVM
; RUN: opt %s -S -passes=inline -o - -experimental-assignment-tracking \
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; RUN: | FileCheck %s
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;; Check that all DIAssignID metadata that are inlined are replaced with new
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;; versions. Otherwise two inlined instances of an assignment will be considered
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;; to be the same assignment.
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;;
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;; $cat test.cpp
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;; __attribute__((always_inline))
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;; int get() { int val = 5; return val; }
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;; void fun() {
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;; get();
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;; get();
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;; }
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; CHECK-LABEL: _Z3funv
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;
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; CHECK: store i32 5, ptr %val.i, align 4{{.*}}, !DIAssignID [[ID_0:![0-9]+]]
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; CHECK-NEXT: call void @llvm.dbg.assign(metadata i32 5, metadata [[val:![0-9]+]], metadata !DIExpression(), metadata [[ID_0]], metadata ptr %val.i, metadata !DIExpression()), !dbg [[dl_inline_0:![0-9]+]]
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;
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; CHECK: store i32 5, ptr %val.i1, align 4{{.*}}, !DIAssignID [[ID_1:![0-9]+]]
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; CHECK-NEXT: call void @llvm.dbg.assign(metadata i32 5, metadata [[val]], metadata !DIExpression(), metadata [[ID_1]], metadata ptr %val.i1, metadata !DIExpression()), !dbg [[dl_inline_1:![0-9]+]]
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;
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; CHECK-DAG: [[val]] = !DILocalVariable(name: "val",
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; CHECK-DAG: [[dl_inline_0]] = !DILocation({{.*}}inlinedAt
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; CHECK-DAG: [[dl_inline_1]] = !DILocation({{.*}}inlinedAt
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; CHECK-DAG: [[ID_0]] = distinct !DIAssignID()
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; CHECK-DAG: [[ID_1]] = distinct !DIAssignID()
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define dso_local i32 @_Z3getv() !dbg !7 {
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entry:
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%val = alloca i32, align 4, !DIAssignID !13
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call void @llvm.dbg.assign(metadata i1 undef, metadata !12, metadata !DIExpression(), metadata !13, metadata ptr %val, metadata !DIExpression()), !dbg !14
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%0 = bitcast ptr %val to ptr, !dbg !15
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call void @llvm.lifetime.start.p0i8(i64 4, ptr %0), !dbg !15
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store i32 5, ptr %val, align 4, !dbg !16, !DIAssignID !21
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call void @llvm.dbg.assign(metadata i32 5, metadata !12, metadata !DIExpression(), metadata !21, metadata ptr %val, metadata !DIExpression()), !dbg !14
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%1 = load i32, ptr %val, align 4, !dbg !22
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%2 = bitcast ptr %val to ptr, !dbg !23
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call void @llvm.lifetime.end.p0i8(i64 4, ptr %2), !dbg !23
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ret i32 %1, !dbg !24
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}
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declare void @llvm.lifetime.start.p0i8(i64 immarg, ptr nocapture)
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declare void @llvm.dbg.declare(metadata, metadata, metadata)
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declare void @llvm.lifetime.end.p0i8(i64 immarg, ptr nocapture)
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declare void @llvm.dbg.assign(metadata, metadata, metadata, metadata, metadata, metadata)
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; Function Attrs: nounwind uwtable mustprogress
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define dso_local void @_Z3funv() !dbg !25 {
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entry:
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%call = call i32 @_Z3getv(), !dbg !28
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%call1 = call i32 @_Z3getv(), !dbg !29
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ret void, !dbg !30
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}
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!llvm.dbg.cu = !{!0}
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!llvm.module.flags = !{!3, !4, !5}
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!llvm.ident = !{!6}
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!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 12.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
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!1 = !DIFile(filename: "test.cpp", directory: "")
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!2 = !{}
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!3 = !{i32 7, !"Dwarf Version", i32 4}
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!4 = !{i32 2, !"Debug Info Version", i32 3}
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!5 = !{i32 1, !"wchar_size", i32 4}
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!6 = !{!"clang version 12.0.0"}
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!7 = distinct !DISubprogram(name: "get", linkageName: "_Z3getv", scope: !1, file: !1, line: 2, type: !8, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !11)
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!8 = !DISubroutineType(types: !9)
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!9 = !{!10}
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!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
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!11 = !{!12}
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!12 = !DILocalVariable(name: "val", scope: !7, file: !1, line: 2, type: !10)
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!13 = distinct !DIAssignID()
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!14 = !DILocation(line: 0, scope: !7)
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!15 = !DILocation(line: 2, column: 13, scope: !7)
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!16 = !DILocation(line: 2, column: 17, scope: !7)
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!21 = distinct !DIAssignID()
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!22 = !DILocation(line: 2, column: 33, scope: !7)
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!23 = !DILocation(line: 2, column: 38, scope: !7)
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!24 = !DILocation(line: 2, column: 26, scope: !7)
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!25 = distinct !DISubprogram(name: "fun", linkageName: "_Z3funv", scope: !1, file: !1, line: 3, type: !26, scopeLine: 3, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
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!26 = !DISubroutineType(types: !27)
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!27 = !{null}
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!28 = !DILocation(line: 4, column: 3, scope: !25)
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!29 = !DILocation(line: 5, column: 3, scope: !25)
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!30 = !DILocation(line: 6, column: 1, scope: !25)
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