[llvm] r317120 - loop-rotate: eliminate duplicate debug intrinsics after splicing.

Adrian Prantl via llvm-commits llvm-commits at lists.llvm.org
Wed Nov 1 13:43:30 PDT 2017


Author: adrian
Date: Wed Nov  1 13:43:30 2017
New Revision: 317120

URL: http://llvm.org/viewvc/llvm-project?rev=317120&view=rev
Log:
loop-rotate: eliminate duplicate debug intrinsics after splicing.

Fixes part of PR35113.

This reapplies r317105 with an additional check for isa<Instruction>
as found by the bots.

Added:
    llvm/trunk/test/Transforms/LoopRotate/dbg-value-duplicates.ll
Modified:
    llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp

Modified: llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp?rev=317120&r1=317119&r2=317120&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp Wed Nov  1 13:43:30 2017
@@ -23,11 +23,13 @@
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instruction.h"
 #include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/User.h"
@@ -142,8 +144,16 @@ bool llvm::MergeBlockIntoPredecessor(Bas
   }
 
   // Begin by getting rid of unneeded PHIs.
-  if (isa<PHINode>(BB->front()))
+  SmallVector<Value *, 4> IncomingValues;
+  if (isa<PHINode>(BB->front())) {
+    for (auto &I : *BB)
+      if (PHINode *PN = dyn_cast<PHINode>(&I)) {
+        if (PN->getIncomingValue(0) != PN)
+          IncomingValues.push_back(PN->getIncomingValue(0));
+      } else
+        break;
     FoldSingleEntryPHINodes(BB, MemDep);
+  }
 
   // Delete the unconditional branch from the predecessor...
   PredBB->getInstList().pop_back();
@@ -155,6 +165,21 @@ bool llvm::MergeBlockIntoPredecessor(Bas
   // Move all definitions in the successor to the predecessor...
   PredBB->getInstList().splice(PredBB->end(), BB->getInstList());
 
+  // Eliminate duplicate dbg.values describing the entry PHI node post-splice.
+  for (auto *Incoming : IncomingValues) {
+    if (isa<Instruction>(Incoming)) {
+      SmallVector<DbgValueInst *, 2> DbgValues;
+      SmallDenseSet<std::pair<DILocalVariable *, DIExpression *>, 2>
+          DbgValueSet;
+      llvm::findDbgValues(DbgValues, Incoming);
+      for (auto &DVI : DbgValues) {
+        auto R = DbgValueSet.insert({DVI->getVariable(), DVI->getExpression()});
+        if (!R.second)
+          DVI->eraseFromParent();
+      }
+    }
+  }
+
   // Inherit predecessors name if it exists.
   if (!PredBB->hasName())
     PredBB->takeName(BB);

Added: llvm/trunk/test/Transforms/LoopRotate/dbg-value-duplicates.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopRotate/dbg-value-duplicates.ll?rev=317120&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopRotate/dbg-value-duplicates.ll (added)
+++ llvm/trunk/test/Transforms/LoopRotate/dbg-value-duplicates.ll Wed Nov  1 13:43:30 2017
@@ -0,0 +1,86 @@
+; RUN: opt -S -loop-rotate < %s | FileCheck %s
+source_filename = "/tmp/loop.c"
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.13.0"
+
+; Function Attrs: nounwind ssp uwtable
+define void @f(float* %input, i64 %n, i64 %s) local_unnamed_addr #0 !dbg !8 {
+entry:
+  call void @llvm.dbg.value(metadata float* %input, metadata !15, metadata !DIExpression()), !dbg !20
+  call void @llvm.dbg.value(metadata i64 %n, metadata !16, metadata !DIExpression()), !dbg !21
+  call void @llvm.dbg.value(metadata i64 %s, metadata !17, metadata !DIExpression()), !dbg !22
+  call void @llvm.dbg.value(metadata i64 0, metadata !18, metadata !DIExpression()), !dbg !23
+  br label %for.cond, !dbg !24
+
+for.cond:                                         ; preds = %for.body, %entry
+  ; CHECK: %i.02 = phi i64 [ 0, %for.body.lr.ph ], [ %add, %for.body ]
+  %i.0 = phi i64 [ 0, %entry ], [ %add, %for.body ]
+  call void @llvm.dbg.value(metadata i64 %i.0, metadata !18, metadata !DIExpression()), !dbg !23
+  %cmp = icmp slt i64 %i.0, %n, !dbg !25
+  br i1 %cmp, label %for.body, label %for.cond.cleanup, !dbg !27
+
+for.cond.cleanup:                                 ; preds = %for.cond
+  ret void, !dbg !28
+
+for.body:                                         ; preds = %for.cond
+  %arrayidx = getelementptr inbounds float, float* %input, i64 %i.0, !dbg !29
+  %0 = load float, float* %arrayidx, align 4, !dbg !29, !tbaa !30
+  call void @bar(float %0), !dbg !34
+  %add = add nsw i64 %i.0, %s, !dbg !35
+  call void @llvm.dbg.value(metadata i64 %add, metadata !18, metadata !DIExpression()), !dbg !23
+  ; CHECK:   call void @llvm.dbg.value(metadata i64 %add, metadata !18, metadata !DIExpression()), !dbg !23
+  ; CHECK-NOT:   call void @llvm.dbg.value(metadata i64 %add, metadata !18, metadata !DIExpression()), !dbg !23
+  br label %for.cond, !dbg !36, !llvm.loop !37
+}
+
+declare void @bar(float) local_unnamed_addr #1
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #2
+
+attributes #0 = { nounwind ssp uwtable }
+attributes #2 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.ident = !{!7}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0 (trunk 316689) (llvm/trunk 316685)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "/tmp/loop.c", directory: "/Data/llvm")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{i32 7, !"PIC Level", i32 2}
+!7 = !{!"clang version 6.0.0 (trunk 316689) (llvm/trunk 316685)"}
+!8 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 2, type: !9, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !14)
+!9 = !DISubroutineType(types: !10)
+!10 = !{null, !11, !13, !13}
+!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64)
+!12 = !DIBasicType(name: "float", size: 32, encoding: DW_ATE_float)
+!13 = !DIBasicType(name: "long long int", size: 64, encoding: DW_ATE_signed)
+!14 = !{!15, !16, !17, !18}
+!15 = !DILocalVariable(name: "input", arg: 1, scope: !8, file: !1, line: 2, type: !11)
+!16 = !DILocalVariable(name: "n", arg: 2, scope: !8, file: !1, line: 2, type: !13)
+!17 = !DILocalVariable(name: "s", arg: 3, scope: !8, file: !1, line: 2, type: !13)
+!18 = !DILocalVariable(name: "i", scope: !19, file: !1, line: 3, type: !13)
+!19 = distinct !DILexicalBlock(scope: !8, file: !1, line: 3, column: 3)
+!20 = !DILocation(line: 2, column: 15, scope: !8)
+!21 = !DILocation(line: 2, column: 32, scope: !8)
+!22 = !DILocation(line: 2, column: 45, scope: !8)
+!23 = !DILocation(line: 3, column: 18, scope: !19)
+!24 = !DILocation(line: 3, column: 8, scope: !19)
+!25 = !DILocation(line: 3, column: 26, scope: !26)
+!26 = distinct !DILexicalBlock(scope: !19, file: !1, line: 3, column: 3)
+!27 = !DILocation(line: 3, column: 3, scope: !19)
+!28 = !DILocation(line: 5, column: 1, scope: !8)
+!29 = !DILocation(line: 4, column: 9, scope: !26)
+!30 = !{!31, !31, i64 0}
+!31 = !{!"float", !32, i64 0}
+!32 = !{!"omnipotent char", !33, i64 0}
+!33 = !{!"Simple C/C++ TBAA"}
+!34 = !DILocation(line: 4, column: 5, scope: !26)
+!35 = !DILocation(line: 3, column: 31, scope: !26)
+!36 = !DILocation(line: 3, column: 3, scope: !26)
+!37 = distinct !{!37, !27, !38}
+!38 = !DILocation(line: 4, column: 17, scope: !19)




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