[llvm] da52aa2 - [LICM] When promoting loads to the preheader, drop the location.
Davide Italiano via llvm-commits
llvm-commits at lists.llvm.org
Thu May 14 17:05:33 PDT 2020
Author: Davide Italiano
Date: 2020-05-14T17:05:23-07:00
New Revision: da52aa2c3340d91025c0188175012c476967dc74
URL: https://github.com/llvm/llvm-project/commit/da52aa2c3340d91025c0188175012c476967dc74
DIFF: https://github.com/llvm/llvm-project/commit/da52aa2c3340d91025c0188175012c476967dc74.diff
LOG: [LICM] When promoting loads to the preheader, drop the location.
It's really almost going to be misleading, see the example in
https://bugs.llvm.org/show_bug.cgi?id=45820
Maybe at some point we can do something fancier, but at least
this will fix a bug where we step on dead code while debugging.
Added:
llvm/test/Transforms/LICM/hoisting-preheader-debugloc.ll
Modified:
llvm/lib/Transforms/Scalar/LICM.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index eddf521ca024..df789a8c6469 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -2089,7 +2089,7 @@ bool llvm::promoteLoopAccessesToScalars(
if (SawUnorderedAtomic)
PreheaderLoad->setOrdering(AtomicOrdering::Unordered);
PreheaderLoad->setAlignment(Align(Alignment));
- PreheaderLoad->setDebugLoc(DL);
+ PreheaderLoad->setDebugLoc(DebugLoc());
if (AATags)
PreheaderLoad->setAAMetadata(AATags);
SSA.AddAvailableValue(Preheader, PreheaderLoad);
diff --git a/llvm/test/Transforms/LICM/hoisting-preheader-debugloc.ll b/llvm/test/Transforms/LICM/hoisting-preheader-debugloc.ll
new file mode 100644
index 000000000000..3721f09eef8f
--- /dev/null
+++ b/llvm/test/Transforms/LICM/hoisting-preheader-debugloc.ll
@@ -0,0 +1,174 @@
+; RUN: opt -S -licm < %s | FileCheck %s
+
+; CHECK: %arrayidx4.promoted = load i32, i32* %arrayidx4, align 1, !tbaa !59
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at a = dso_local local_unnamed_addr global i16 0, align 2, !dbg !0
+ at b = dso_local local_unnamed_addr global i16 0, align 2, !dbg !6
+
+define dso_local void @c(i32 %d) local_unnamed_addr #0 !dbg !13 {
+entry:
+ call void @llvm.dbg.value(metadata i32 undef, metadata !18, metadata !DIExpression()), !dbg !19
+ ret void, !dbg !20
+}
+
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+define dso_local signext i16 @e(i32 %d) local_unnamed_addr #0 !dbg !21 {
+entry:
+ call void @llvm.dbg.value(metadata i32 %d, metadata !25, metadata !DIExpression()), !dbg !26
+ %conv = trunc i32 %d to i16, !dbg !27
+ ret i16 %conv, !dbg !28
+}
+
+define dso_local signext i16 @g() local_unnamed_addr #2 !dbg !29 {
+entry:
+ %l_284 = alloca [2 x [3 x [6 x i32]]], align 16
+ %0 = bitcast [2 x [3 x [6 x i32]]]* %l_284 to i8*, !dbg !39
+ call void @llvm.lifetime.start.p0i8(i64 144, i8* nonnull %0) #4, !dbg !39
+ call void @llvm.dbg.declare(metadata [2 x [3 x [6 x i32]]]* %l_284, metadata !33, metadata !DIExpression()), !dbg !40
+ %1 = load i16, i16* @a, align 2, !dbg !41, !tbaa !44
+ %cmp11 = icmp sgt i16 %1, -1, !dbg !48
+ br i1 %cmp11, label %for.body.lr.ph, label %cleanup, !dbg !49
+
+for.body.lr.ph: ; preds = %entry
+ br label %for.body, !dbg !49
+
+for.body: ; preds = %for.body.lr.ph, %for.cond2
+ %call = call signext i16 @e(i32 1), !dbg !50
+ %tobool = icmp eq i16 %call, 0, !dbg !50
+ br i1 %tobool, label %for.cond2, label %for.body.cleanup_crit_edge, !dbg !53
+
+for.cond2: ; preds = %for.body
+ %arrayidx4 = getelementptr inbounds [2 x [3 x [6 x i32]]], [2 x [3 x [6 x i32]]]* %l_284, i64 0, i64 1, i64 2, i64 5, !dbg !54
+ store i32 0, i32* %arrayidx4, align 4, !dbg !58, !tbaa !59
+ %arrayidx8 = getelementptr inbounds [2 x [3 x [6 x i32]]], [2 x [3 x [6 x i32]]]* %l_284, i64 0, i64 1, i64 1, i64 4, !dbg !61
+ %2 = load i32, i32* %arrayidx8, align 8, !dbg !61, !tbaa !59
+ %conv9 = trunc i32 %2 to i16, !dbg !61
+ store i16 %conv9, i16* @b, align 2, !dbg !62, !tbaa !44
+ %3 = load i16, i16* @a, align 2, !dbg !41, !tbaa !44
+ %cmp = icmp sgt i16 %3, -1, !dbg !48
+ br i1 %cmp, label %for.body, label %for.cond.cleanup_crit_edge, !dbg !49, !llvm.loop !63
+
+for.cond.cleanup_crit_edge: ; preds = %for.cond2
+ br label %cleanup, !dbg !49
+
+for.body.cleanup_crit_edge: ; preds = %for.body
+ br label %cleanup, !dbg !53
+
+cleanup: ; preds = %for.body.cleanup_crit_edge, %for.cond.cleanup_crit_edge, %entry
+ call void @llvm.lifetime.end.p0i8(i64 144, i8* nonnull %0) #4, !dbg !66
+ ret i16 1, !dbg !66
+}
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture) #3
+
+; Function Attrs: norecurse nounwind readnone uwtable
+define internal signext i16 @f(i32 %d) #0 !dbg !67 {
+entry:
+ call void @llvm.dbg.value(metadata i32 %d, metadata !69, metadata !DIExpression()), !dbg !70
+ ret i16 undef, !dbg !71
+}
+
+; Function Attrs: argmemonly nounwind willreturn
+declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture) #3
+
+; Function Attrs: nounwind uwtable
+define dso_local i32 @main() local_unnamed_addr #2 !dbg !72 {
+entry:
+ %call = call signext i16 @g(), !dbg !75
+ ret i32 0, !dbg !76
+}
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+attributes #0 = { norecurse nounwind readnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="none" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable willreturn }
+attributes #2 = { nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="none" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #3 = { argmemonly nounwind willreturn }
+attributes #4 = { nounwind }
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!9, !10, !11}
+!llvm.ident = !{!12}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !8, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 11.0.0 (https://github.com/llvm/llvm-project.git 237d0e3c0416abf9919406bcc92874cfd15f5e0c)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "a.c", directory: "/home/davide/lldb-build/bin")
+!4 = !{}
+!5 = !{!0, !6}
+!6 = !DIGlobalVariableExpression(var: !7, expr: !DIExpression())
+!7 = distinct !DIGlobalVariable(name: "b", scope: !2, file: !3, line: 1, type: !8, isLocal: false, isDefinition: true)
+!8 = !DIBasicType(name: "short", size: 16, encoding: DW_ATE_signed)
+!9 = !{i32 7, !"Dwarf Version", i32 4}
+!10 = !{i32 2, !"Debug Info Version", i32 3}
+!11 = !{i32 1, !"wchar_size", i32 4}
+!12 = !{!"clang version 11.0.0 (https://github.com/llvm/llvm-project.git 237d0e3c0416abf9919406bcc92874cfd15f5e0c)"}
+!13 = distinct !DISubprogram(name: "c", scope: !3, file: !3, line: 2, type: !14, scopeLine: 2, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !17)
+!14 = !DISubroutineType(types: !15)
+!15 = !{null, !16}
+!16 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!17 = !{!18}
+!18 = !DILocalVariable(name: "d", arg: 1, scope: !13, file: !3, line: 2, type: !16)
+!19 = !DILocation(line: 0, scope: !13)
+!20 = !DILocation(line: 2, column: 13, scope: !13)
+!21 = distinct !DISubprogram(name: "e", scope: !3, file: !3, line: 3, type: !22, scopeLine: 3, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !24)
+!22 = !DISubroutineType(types: !23)
+!23 = !{!8, !16}
+!24 = !{!25}
+!25 = !DILocalVariable(name: "d", arg: 1, scope: !21, file: !3, line: 3, type: !16)
+!26 = !DILocation(line: 0, scope: !21)
+!27 = !DILocation(line: 3, column: 22, scope: !21)
+!28 = !DILocation(line: 3, column: 15, scope: !21)
+!29 = distinct !DISubprogram(name: "g", scope: !3, file: !3, line: 5, type: !30, scopeLine: 5, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !32)
+!30 = !DISubroutineType(types: !31)
+!31 = !{!8}
+!32 = !{!33}
+!33 = !DILocalVariable(name: "l_284", scope: !29, file: !3, line: 6, type: !34)
+!34 = !DICompositeType(tag: DW_TAG_array_type, baseType: !16, size: 1152, elements: !35)
+!35 = !{!36, !37, !38}
+!36 = !DISubrange(count: 2)
+!37 = !DISubrange(count: 3)
+!38 = !DISubrange(count: 6)
+!39 = !DILocation(line: 6, column: 3, scope: !29)
+!40 = !DILocation(line: 6, column: 7, scope: !29)
+!41 = !DILocation(line: 7, column: 10, scope: !42)
+!42 = distinct !DILexicalBlock(scope: !43, file: !3, line: 7, column: 3)
+!43 = distinct !DILexicalBlock(scope: !29, file: !3, line: 7, column: 3)
+!44 = !{!45, !45, i64 0}
+!45 = !{!"short", !46, i64 0}
+!46 = !{!"omnipotent char", !47, i64 0}
+!47 = !{!"Simple C/C++ TBAA"}
+!48 = !DILocation(line: 7, column: 12, scope: !42)
+!49 = !DILocation(line: 7, column: 3, scope: !43)
+!50 = !DILocation(line: 8, column: 9, scope: !51)
+!51 = distinct !DILexicalBlock(scope: !52, file: !3, line: 8, column: 9)
+!52 = distinct !DILexicalBlock(scope: !42, file: !3, line: 7, column: 19)
+!53 = !DILocation(line: 8, column: 9, scope: !52)
+!54 = !DILocation(line: 11, column: 7, scope: !55)
+!55 = distinct !DILexicalBlock(scope: !56, file: !3, line: 10, column: 14)
+!56 = distinct !DILexicalBlock(scope: !57, file: !3, line: 10, column: 5)
+!57 = distinct !DILexicalBlock(scope: !52, file: !3, line: 10, column: 5)
+!58 = !DILocation(line: 11, column: 22, scope: !55)
+!59 = !{!60, !60, i64 0}
+!60 = !{!"int", !46, i64 0}
+!61 = !DILocation(line: 16, column: 9, scope: !52)
+!62 = !DILocation(line: 16, column: 7, scope: !52)
+!63 = distinct !{!63, !49, !64, !65}
+!64 = !DILocation(line: 17, column: 3, scope: !43)
+!65 = !{!"llvm.loop.unroll.disable"}
+!66 = !DILocation(line: 18, column: 1, scope: !29)
+!67 = distinct !DISubprogram(name: "f", scope: !3, file: !3, line: 4, type: !22, scopeLine: 4, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !68)
+!68 = !{!69}
+!69 = !DILocalVariable(name: "d", arg: 1, scope: !67, file: !3, line: 4, type: !16)
+!70 = !DILocation(line: 0, scope: !67)
+!71 = !DILocation(line: 4, column: 21, scope: !67)
+!72 = distinct !DISubprogram(name: "main", scope: !3, file: !3, line: 19, type: !73, scopeLine: 19, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !4)
+!73 = !DISubroutineType(types: !74)
+!74 = !{!16}
+!75 = !DILocation(line: 19, column: 14, scope: !72)
+!76 = !DILocation(line: 19, column: 19, scope: !72)
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