[llvm] r248769 - Move dbg.declare intrinsics when merging and replacing allocas.
Evgeniy Stepanov via llvm-commits
llvm-commits at lists.llvm.org
Mon Sep 28 17:30:19 PDT 2015
Author: eugenis
Date: Mon Sep 28 19:30:19 2015
New Revision: 248769
URL: http://llvm.org/viewvc/llvm-project?rev=248769&view=rev
Log:
Move dbg.declare intrinsics when merging and replacing allocas.
Place new and update dbg.declare calls immediately after the
corresponding alloca.
Current code in replaceDbgDeclareForAlloca puts the new dbg.declare
at the end of the basic block. LLVM codegen has problems emitting
debug info in a situation when dbg.declare appears after all uses of
the variable. This usually kinda works for inlining and ASan (two
users of this function) but not for SafeStack (see the pending change
in http://reviews.llvm.org/D13178).
Added:
llvm/trunk/test/Transforms/Inline/alloca-dbgdeclare-merge.ll
Modified:
llvm/trunk/lib/Transforms/IPO/Inliner.cpp
llvm/trunk/lib/Transforms/Utils/Local.cpp
llvm/trunk/test/Transforms/Inline/inline_dbg_declare.ll
Modified: llvm/trunk/lib/Transforms/IPO/Inliner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/Inliner.cpp?rev=248769&r1=248768&r2=248769&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/Inliner.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/Inliner.cpp Mon Sep 28 19:30:19 2015
@@ -228,6 +228,14 @@ static bool InlineCallIfPossible(Pass &P
DEBUG(dbgs() << " ***MERGED ALLOCA: " << *AI << "\n\t\tINTO: "
<< *AvailableAlloca << '\n');
+ // Move affected dbg.declare calls immediately after the new alloca to
+ // avoid the situation when a dbg.declare preceeds its alloca.
+ if (auto *L = LocalAsMetadata::getIfExists(AI))
+ if (auto *MDV = MetadataAsValue::getIfExists(AI->getContext(), L))
+ for (User *U : MDV->users())
+ if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(U))
+ DDI->moveBefore(AvailableAlloca->getNextNode());
+
AI->replaceAllUsesWith(AvailableAlloca);
if (Align1 != Align2) {
Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=248769&r1=248768&r2=248769&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp Mon Sep 28 19:30:19 2015
@@ -1157,10 +1157,10 @@ bool llvm::replaceDbgDeclareForAlloca(Al
DIExpr = Builder.createExpression(NewDIExpr);
}
- // Insert llvm.dbg.declare in the same basic block as the original alloca,
- // and remove old llvm.dbg.declare.
- BasicBlock *BB = AI->getParent();
- Builder.insertDeclare(NewAllocaAddress, DIVar, DIExpr, Loc, BB);
+ // Insert llvm.dbg.declare immediately after the original alloca, and remove
+ // old llvm.dbg.declare.
+ Builder.insertDeclare(NewAllocaAddress, DIVar, DIExpr, Loc,
+ AI->getNextNode());
DDI->eraseFromParent();
return true;
}
Added: llvm/trunk/test/Transforms/Inline/alloca-dbgdeclare-merge.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/alloca-dbgdeclare-merge.ll?rev=248769&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Inline/alloca-dbgdeclare-merge.ll (added)
+++ llvm/trunk/test/Transforms/Inline/alloca-dbgdeclare-merge.ll Mon Sep 28 19:30:19 2015
@@ -0,0 +1,102 @@
+; Test that alloca merging in the inliner places dbg.declare calls immediately
+; after the merged alloca. Not at the end of the entry BB, and definitely not
+; before the alloca.
+;
+; clang -g -S -emit-llvm -Xclang -disable-llvm-optzns
+;
+;__attribute__((always_inline)) void f() {
+; char aaa[100];
+; aaa[10] = 1;
+;}
+;
+;__attribute__((always_inline)) void g() {
+; char bbb[100];
+; bbb[20] = 1;
+;}
+;
+;void h() {
+; f();
+; g();
+;}
+;
+; RUN: opt -always-inline -S < %s | FileCheck %s
+;
+; CHECK: define void @h()
+; CHECK-NEXT: entry:
+; CHECK-NEXT: %[[AI:.*]] = alloca [100 x i8]
+; CHECK-NEXT: call void @llvm.dbg.declare(metadata [100 x i8]* %[[AI]],
+; CHECK-NEXT: call void @llvm.dbg.declare(metadata [100 x i8]* %[[AI]],
+
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: alwaysinline nounwind uwtable
+define void @f() #0 {
+entry:
+ %aaa = alloca [100 x i8], align 16
+ call void @llvm.dbg.declare(metadata [100 x i8]* %aaa, metadata !12, metadata !17), !dbg !18
+ %arrayidx = getelementptr inbounds [100 x i8], [100 x i8]* %aaa, i64 0, i64 10, !dbg !19
+ store i8 1, i8* %arrayidx, align 2, !dbg !20
+ ret void, !dbg !21
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+; Function Attrs: alwaysinline nounwind uwtable
+define void @g() #0 {
+entry:
+ %bbb = alloca [100 x i8], align 16
+ call void @llvm.dbg.declare(metadata [100 x i8]* %bbb, metadata !22, metadata !17), !dbg !23
+ %arrayidx = getelementptr inbounds [100 x i8], [100 x i8]* %bbb, i64 0, i64 20, !dbg !24
+ store i8 1, i8* %arrayidx, align 4, !dbg !25
+ ret void, !dbg !26
+}
+
+; Function Attrs: nounwind uwtable
+define void @h() #2 {
+entry:
+ call void @f(), !dbg !27
+ call void @g(), !dbg !28
+ ret void, !dbg !29
+}
+
+attributes #0 = { alwaysinline nounwind uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone }
+attributes #2 = { nounwind uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!9, !10}
+!llvm.ident = !{!11}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.8.0 (trunk 248518) (llvm/trunk 248512)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "../1.c", directory: "/code/llvm-git/build")
+!2 = !{}
+!3 = !{!4, !7, !8}
+!4 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !5, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, function: void ()* @f, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = distinct !DISubprogram(name: "g", scope: !1, file: !1, line: 6, type: !5, isLocal: false, isDefinition: true, scopeLine: 6, isOptimized: false, function: void ()* @g, variables: !2)
+!8 = distinct !DISubprogram(name: "h", scope: !1, file: !1, line: 11, type: !5, isLocal: false, isDefinition: true, scopeLine: 11, isOptimized: false, function: void ()* @h, variables: !2)
+!9 = !{i32 2, !"Dwarf Version", i32 4}
+!10 = !{i32 2, !"Debug Info Version", i32 3}
+!11 = !{!"clang version 3.8.0 (trunk 248518) (llvm/trunk 248512)"}
+!12 = !DILocalVariable(name: "aaa", scope: !4, file: !1, line: 2, type: !13)
+!13 = !DICompositeType(tag: DW_TAG_array_type, baseType: !14, size: 800, align: 8, elements: !15)
+!14 = !DIBasicType(name: "char", size: 8, align: 8, encoding: DW_ATE_signed_char)
+!15 = !{!16}
+!16 = !DISubrange(count: 100)
+!17 = !DIExpression()
+!18 = !DILocation(line: 2, column: 8, scope: !4)
+!19 = !DILocation(line: 3, column: 3, scope: !4)
+!20 = !DILocation(line: 3, column: 11, scope: !4)
+!21 = !DILocation(line: 4, column: 1, scope: !4)
+!22 = !DILocalVariable(name: "bbb", scope: !7, file: !1, line: 7, type: !13)
+!23 = !DILocation(line: 7, column: 8, scope: !7)
+!24 = !DILocation(line: 8, column: 3, scope: !7)
+!25 = !DILocation(line: 8, column: 11, scope: !7)
+!26 = !DILocation(line: 9, column: 1, scope: !7)
+!27 = !DILocation(line: 12, column: 3, scope: !8)
+!28 = !DILocation(line: 13, column: 3, scope: !8)
+!29 = !DILocation(line: 14, column: 1, scope: !8)
Modified: llvm/trunk/test/Transforms/Inline/inline_dbg_declare.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/inline_dbg_declare.ll?rev=248769&r1=248768&r2=248769&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/Inline/inline_dbg_declare.ll (original)
+++ llvm/trunk/test/Transforms/Inline/inline_dbg_declare.ll Mon Sep 28 19:30:19 2015
@@ -42,6 +42,7 @@ define void @bar(float* %dst) #0 {
entry:
; CHECK: [[x_addr_i:%[a-zA-Z0-9.]+]] = alloca float, align 4
+; CHECK-NEXT: void @llvm.dbg.declare(metadata float* [[x_addr_i]], metadata [[m23:![0-9]+]], metadata !{{[0-9]+}}), !dbg [[m24:![0-9]+]]
%dst.addr = alloca float*, align 4
store float* %dst, float** %dst.addr, align 4
@@ -52,7 +53,6 @@ entry:
%call = call float @foo(float %1), !dbg !22
; CHECK-NOT: call float @foo
-; CHECK: void @llvm.dbg.declare(metadata float* [[x_addr_i]], metadata [[m23:![0-9]+]], metadata !{{[0-9]+}}), !dbg [[m24:![0-9]+]]
%2 = load float*, float** %dst.addr, align 4, !dbg !22
%arrayidx1 = getelementptr inbounds float, float* %2, i32 0, !dbg !22
@@ -95,5 +95,5 @@ attributes #1 = { nounwind readnone }
; CHECK: [[FOO:![0-9]+]] = distinct !DISubprogram(name: "foo",
; CHECK: [[BAR:![0-9]+]] = distinct !DISubprogram(name: "bar",
; CHECK: [[m23]] = !DILocalVariable(name: "x", arg: 1, scope: [[FOO]]
-; CHECK: [[CALL_SITE:![0-9]+]] = distinct !DILocation(line: 8, column: 14, scope: [[BAR]])
-; CHECK: [[m24]] = !DILocation(line: 1, column: 17, scope: [[FOO]], inlinedAt: [[CALL_SITE]])
+; CHECK: [[m24]] = !DILocation(line: 1, column: 17, scope: [[FOO]], inlinedAt: [[CALL_SITE:![0-9]+]])
+; CHECK: [[CALL_SITE]] = distinct !DILocation(line: 8, column: 14, scope: [[BAR]])
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