[llvm] r372703 - [Debuginfo] dbg.value points to undef value after Induction Variable Simplification.

Alexey Lapshin via llvm-commits llvm-commits at lists.llvm.org
Tue Sep 24 01:47:03 PDT 2019


Author: avl
Date: Tue Sep 24 01:47:03 2019
New Revision: 372703

URL: http://llvm.org/viewvc/llvm-project?rev=372703&view=rev
Log:
[Debuginfo] dbg.value points to undef value after Induction Variable Simplification.

Induction Variable Simplification pass does not update dbg.value intrinsic.

Before:

%add = add nuw nsw i32 %ArgIndex.06, 1
call void @llvm.dbg.value(metadata i32 %add, metadata !17, metadata !DIExpression())

After:

%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
call void @llvm.dbg.value(metadata i64 undef, metadata !17, metadata !DIExpression())

There should be:

%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
call void @llvm.dbg.value(metadata i64 %indvars.iv.next, metadata !17, metadata !DIExpression())

Differential Revision: https://reviews.llvm.org/D67770

Added:
    llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value.ll
    llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value2.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp?rev=372703&r1=372702&r2=372703&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp Tue Sep 24 01:47:03 2019
@@ -1672,6 +1672,10 @@ Instruction *WidenIV::widenIVUse(NarrowI
     return nullptr;
   }
 
+  // if we reached this point then we are going to replace
+  // DU.NarrowUse with WideUse. Reattach DbgValue then.
+  replaceAllDbgUsesWith(*DU.NarrowUse, *WideUse, *WideUse, *DT);
+
   ExtendKindMap[DU.NarrowUse] = WideAddRec.second;
   // Returning WideUse pushes it on the worklist.
   return WideUse;
@@ -1797,14 +1801,9 @@ PHINode *WidenIV::createWideIV(SCEVExpan
       DeadInsts.emplace_back(DU.NarrowDef);
   }
 
-  // Attach any debug information to the new PHI. Since OrigPhi and WidePHI
-  // evaluate the same recurrence, we can just copy the debug info over.
-  SmallVector<DbgValueInst *, 1> DbgValues;
-  llvm::findDbgValues(DbgValues, OrigPhi);
-  auto *MDPhi = MetadataAsValue::get(WidePhi->getContext(),
-                                     ValueAsMetadata::get(WidePhi));
-  for (auto &DbgValue : DbgValues)
-    DbgValue->setOperand(0, MDPhi);
+  // Attach any debug information to the new PHI.
+  replaceAllDbgUsesWith(*OrigPhi, *WidePhi, *WidePhi, *DT);
+
   return WidePhi;
 }
 
@@ -2845,7 +2844,7 @@ bool IndVarSimplify::run(Loop *L) {
       // that our definition of "high cost" is not exactly principled.  
       if (Rewriter.isHighCostExpansion(ExitCount, L))
         continue;
-      
+
       // Check preconditions for proper SCEVExpander operation. SCEV does not
       // express SCEVExpander's dependencies, such as LoopSimplify. Instead
       // any pass that uses the SCEVExpander must do it. This does not work

Added: llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value.ll?rev=372703&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value.ll (added)
+++ llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value.ll Tue Sep 24 01:47:03 2019
@@ -0,0 +1,92 @@
+; RUN: opt %s -indvars -verify -S -o - | FileCheck %s
+
+; Hand-reduced from this example:
+;
+; #include <stdio.h>
+
+; int main( int argc, char **argv )
+; {
+;    for( int ArgIndex = 1; ArgIndex < argc; ArgIndex += 1 )
+;    {
+;       printf("\n Argument %d:  %s\n", ArgIndex, argv[ArgIndex] );
+;    }
+; }
+
+; clang++ -g -O -mllvm -disable-llvm-optzns -gno-column-info
+; opt  -mem2reg -loop-rotate -scalar-evolution
+
+; CHECK: @main
+; CHECK: llvm.dbg.value(metadata i32 1, metadata [[METADATA_IDX1:![0-9]+]]
+; CHECK: %[[VAR_NAME:.*]] = add nuw nsw i64
+; CHECK: llvm.dbg.value(metadata i64 %[[VAR_NAME]], metadata [[METADATA_IDX1]], metadata !DIExpression())
+; CHECK: DICompileUnit
+; CHECK: [[METADATA_IDX1]] = !DILocalVariable(name: "ArgIndex"
+
+source_filename = "test.cpp"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at .str = private unnamed_addr constant [20 x i8] c"\0A Argument %d:  %s\0A\00", align 1
+
+define dso_local i32 @main(i32 %argc, i8** %argv) !dbg !7 {
+entry:
+  call void @llvm.dbg.value(metadata i32 1, metadata !17, metadata !DIExpression()), !dbg !19
+  %cmp1 = icmp slt i32 1, %argc, !dbg !19
+  br i1 %cmp1, label %for.body.lr.ph, label %for.cond.cleanup, !dbg !19
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body, !dbg !19
+
+for.cond.for.cond.cleanup_crit_edge:              ; preds = %for.inc
+  br label %for.cond.cleanup, !dbg !19
+
+for.cond.cleanup:                                 ; preds = %for.cond.for.cond.cleanup_crit_edge, %entry
+  br label %for.end
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.inc
+  %ArgIndex.02 = phi i32 [ 1, %for.body.lr.ph ], [ %add, %for.inc ]
+  call void @llvm.dbg.value(metadata i32 %ArgIndex.02, metadata !17, metadata !DIExpression()), !dbg !19
+  %idxprom = sext i32 %ArgIndex.02 to i64, !dbg !19
+  %arrayidx = getelementptr inbounds i8*, i8** %argv, i64 %idxprom, !dbg !19
+  %0 = load i8*, i8** %arrayidx, align 8, !dbg !19
+  %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str, i64 0, i64 0), i32 %ArgIndex.02, i8* %0), !dbg !19
+  br label %for.inc, !dbg !19
+
+for.inc:                                          ; preds = %for.body
+  %add = add nsw i32 %ArgIndex.02, 1, !dbg !19
+  call void @llvm.dbg.value(metadata i32 %add, metadata !17, metadata !DIExpression()), !dbg !19
+  %cmp = icmp slt i32 %add, %argc, !dbg !19
+  br i1 %cmp, label %for.body, label %for.cond.for.cond.cleanup_crit_edge, !dbg !19, !llvm.loop !19
+
+for.end:                                          ; preds = %for.cond.cleanup
+  ret i32 0, !dbg !19
+}
+
+declare dso_local i32 @printf(i8*, ...)
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang"}
+!7 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 4, type: !8, scopeLine: 5, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !14)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10, !10, !11}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64)
+!12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !13, size: 64)
+!13 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!14 = !{!15, !16, !17}
+!15 = !DILocalVariable(name: "argc", arg: 1, scope: !7, file: !1, line: 4, type: !10)
+!16 = !DILocalVariable(name: "argv", arg: 2, scope: !7, file: !1, line: 4, type: !11)
+!17 = !DILocalVariable(name: "ArgIndex", scope: !18, file: !1, line: 6, type: !10)
+!18 = distinct !DILexicalBlock(scope: !7, file: !1, line: 6)
+!19 = !DILocation(line: 0, scope: !7)

Added: llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value2.ll?rev=372703&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value2.ll (added)
+++ llvm/trunk/test/Transforms/IndVarSimplify/indvar-debug-value2.ll Tue Sep 24 01:47:03 2019
@@ -0,0 +1,90 @@
+; RUN: opt %s -indvars -verify -S -o - | FileCheck %s
+
+; Hand-reduced from this example:
+;
+; #include <stdio.h>
+
+; int main( int argc, char **argv )
+; {
+;    for( int ArgIndex = 1; ArgIndex < argc; ArgIndex += 1 )
+;    {
+;       printf("\n Argument %d:  %s\n", ArgIndex, argv[ArgIndex] );
+;    }
+; }
+
+; clang++ -g -O -mllvm -disable-llvm-optzns -gno-column-info
+; opt  -mem2reg -scalar-evolution
+
+; CHECK: @main
+; CHECK: llvm.dbg.value(metadata i32 1, metadata [[METADATA_IDX1:![0-9]+]]
+; CHECK: %[[VAR_NAME:.*]] = add nuw nsw i64
+; CHECK: llvm.dbg.value(metadata i64 %[[VAR_NAME]], metadata [[METADATA_IDX1]], metadata !DIExpression())
+; CHECK: DICompileUnit
+; CHECK: [[METADATA_IDX1]] = !DILocalVariable(name: "ArgIndex"
+
+source_filename = "test.cpp"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+ at .str = private unnamed_addr constant [20 x i8] c"\0A Argument %d:  %s\0A\00", align 1
+
+define dso_local i32 @main(i32 %argc, i8** %argv) !dbg !7 {
+entry:
+  call void @llvm.dbg.value(metadata i32 %argc, metadata !15, metadata !DIExpression()), !dbg !19
+  call void @llvm.dbg.value(metadata i8** %argv, metadata !16, metadata !DIExpression()), !dbg !19
+  call void @llvm.dbg.value(metadata i32 1, metadata !17, metadata !DIExpression()), !dbg !19
+  br label %for.cond, !dbg !19
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %ArgIndex.0 = phi i32 [ 1, %entry ], [ %add, %for.inc ], !dbg !19
+  call void @llvm.dbg.value(metadata i32 %ArgIndex.0, metadata !17, metadata !DIExpression()), !dbg !19
+  %cmp = icmp slt i32 %ArgIndex.0, %argc, !dbg !19
+  br i1 %cmp, label %for.body, label %for.cond.cleanup, !dbg !19
+
+for.cond.cleanup:                                 ; preds = %for.cond
+  br label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %idxprom = sext i32 %ArgIndex.0 to i64, !dbg !19
+  %arrayidx = getelementptr inbounds i8*, i8** %argv, i64 %idxprom, !dbg !19
+  %0 = load i8*, i8** %arrayidx, align 8, !dbg !19
+  %call = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str, i64 0, i64 0), i32 %ArgIndex.0, i8* %0), !dbg !19
+  br label %for.inc, !dbg !19
+
+for.inc:                                          ; preds = %for.body
+  %add = add nsw i32 %ArgIndex.0, 1, !dbg !19
+  call void @llvm.dbg.value(metadata i32 %add, metadata !17, metadata !DIExpression()), !dbg !19
+  br label %for.cond, !dbg !19, !llvm.loop !19
+
+for.end:                                          ; preds = %for.cond.cleanup
+  ret i32 0, !dbg !19
+}
+
+declare dso_local i32 @printf(i8*, ...)
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang"}
+!7 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 4, type: !8, scopeLine: 5, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !14)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10, !10, !11}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64)
+!12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !13, size: 64)
+!13 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!14 = !{!15, !16, !17}
+!15 = !DILocalVariable(name: "argc", arg: 1, scope: !7, file: !1, line: 4, type: !10)
+!16 = !DILocalVariable(name: "argv", arg: 2, scope: !7, file: !1, line: 4, type: !11)
+!17 = !DILocalVariable(name: "ArgIndex", scope: !18, file: !1, line: 6, type: !10)
+!18 = distinct !DILexicalBlock(scope: !7, file: !1, line: 6)
+!19 = !DILocation(line: 0, scope: !7)




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