[llvm] r297982 - Revert commit r297971 because of issues reported by msan.

Adrian Prantl via llvm-commits llvm-commits at lists.llvm.org
Thu Mar 16 13:11:54 PDT 2017


Author: adrian
Date: Thu Mar 16 15:11:54 2017
New Revision: 297982

URL: http://llvm.org/viewvc/llvm-project?rev=297982&view=rev
Log:
Revert commit r297971 because of issues reported by msan.

Removed:
    llvm/trunk/test/Transforms/InstCombine/debuginfo-dce.ll
Modified:
    llvm/trunk/include/llvm/Transforms/Utils/Local.h
    llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h
    llvm/trunk/lib/Transforms/Utils/Local.cpp

Modified: llvm/trunk/include/llvm/Transforms/Utils/Local.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/Local.h?rev=297982&r1=297981&r2=297982&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/Local.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/Local.h Thu Mar 16 15:11:54 2017
@@ -282,12 +282,8 @@ bool LowerDbgDeclare(Function &F);
 /// Finds the llvm.dbg.declare intrinsic corresponding to an alloca, if any.
 DbgDeclareInst *FindAllocaDbgDeclare(Value *V);
 
-/// Finds the llvm.dbg.value intrinsics describing a value and invoke \p Action
-/// on it.
-void findDbgValues(Value *V, std::function<void(DbgValueInst &)> Action);
-
-/// Constants for \p replaceDbgDeclare and friends.
-enum { NoDeref = false, WithDeref = true };
+/// Finds the llvm.dbg.value intrinsics describing a value, if any.
+void findDbgValues(SmallVectorImpl<DbgValueInst *> &DbgValues, Value *V);
 
 /// Replaces llvm.dbg.declare instruction when the address it describes
 /// is replaced with a new value. If Deref is true, an additional DW_OP_deref is
@@ -314,11 +310,6 @@ bool replaceDbgDeclareForAlloca(AllocaIn
 void replaceDbgValueForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
                               DIBuilder &Builder, int Offset = 0);
 
-/// Assuming the instruction \p I is going to be deleted, attempt to salvage any
-/// dbg.value intrinsics referring to \p I by rewriting its effect into a
-/// DIExpression.
-void salvageDebugInfo(Instruction &I);
-
 /// Remove all instructions from a basic block other than it's terminator
 /// and any present EH pad instructions.
 unsigned removeAllNonTerminatorAndEHPadInstructions(BasicBlock *BB);

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h?rev=297982&r1=297981&r2=297982&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h Thu Mar 16 15:11:54 2017
@@ -28,9 +28,6 @@
 #include "llvm/IR/PatternMatch.h"
 #include "llvm/Pass.h"
 #include "llvm/Transforms/InstCombine/InstCombineWorklist.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Support/Dwarf.h"
-#include "llvm/IR/DIBuilder.h"
 
 #define DEBUG_TYPE "instcombine"
 
@@ -473,9 +470,8 @@ public:
   /// methods should return the value returned by this function.
   Instruction *eraseInstFromFunction(Instruction &I) {
     DEBUG(dbgs() << "IC: ERASE " << I << '\n');
-    assert(I.use_empty() && "Cannot erase instruction that is used!");
-    salvageDebugInfo(I);
 
+    assert(I.use_empty() && "Cannot erase instruction that is used!");
     // Make sure that we reprocess all operands now that we reduced their
     // use counts.
     if (I.getNumOperands() < 8) {

Modified: llvm/trunk/lib/Transforms/Utils/Local.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/Local.cpp?rev=297982&r1=297981&r2=297982&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/Local.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/Local.cpp Thu Mar 16 15:11:54 2017
@@ -1085,14 +1085,15 @@ static bool PhiHasDebugValue(DILocalVari
   // Since we can't guarantee that the original dbg.declare instrinsic
   // is removed by LowerDbgDeclare(), we need to make sure that we are
   // not inserting the same dbg.value intrinsic over and over.
-  bool Found = false;
-  findDbgValues(APN, [&](DbgValueInst &DVI) {
-    assert(DVI.getValue() == APN);
-    assert(DVI.getOffset() == 0);
-    if ((DVI.getVariable() == DIVar) && (DVI.getExpression() == DIExpr))
-      Found = true;
-  });
-  return Found;
+  SmallVector<DbgValueInst *, 1> DbgValues;
+  findDbgValues(DbgValues, APN);
+  for (auto *DVI : DbgValues) {
+    assert(DVI->getValue() == APN);
+    assert(DVI->getOffset() == 0);
+    if ((DVI->getVariable() == DIVar) && (DVI->getExpression() == DIExpr))
+      return true;
+  }
+  return false;
 }
 
 /// Inserts a llvm.dbg.value intrinsic before a store to an alloca'd value
@@ -1250,40 +1251,44 @@ DbgDeclareInst *llvm::FindAllocaDbgDecla
   return nullptr;
 }
 
-void llvm::findDbgValues(Value *V, std::function<void(DbgValueInst &)> Action) {
+void llvm::findDbgValues(SmallVectorImpl<DbgValueInst *> &DbgValues, Value *V) {
   if (auto *L = LocalAsMetadata::getIfExists(V))
     if (auto *MDV = MetadataAsValue::getIfExists(V->getContext(), L))
       for (User *U : MDV->users())
         if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(U))
-          Action(*DVI);
+          DbgValues.push_back(DVI);
+}
+
+static void DIExprAddDeref(SmallVectorImpl<uint64_t> &Expr) {
+  Expr.push_back(dwarf::DW_OP_deref);
 }
 
-static void appendOffset(SmallVectorImpl<uint64_t> &Ops, int64_t Offset) {
+static void DIExprAddOffset(SmallVectorImpl<uint64_t> &Expr, int Offset) {
   if (Offset > 0) {
-    Ops.push_back(dwarf::DW_OP_plus);
-    Ops.push_back(Offset);
+    Expr.push_back(dwarf::DW_OP_plus);
+    Expr.push_back(Offset);
   } else if (Offset < 0) {
-    Ops.push_back(dwarf::DW_OP_minus);
-    Ops.push_back(-Offset);
+    Expr.push_back(dwarf::DW_OP_minus);
+    Expr.push_back(-Offset);
   }
 }
 
-/// Prepend \p DIExpr with a deref and offset operation.
-static DIExpression *prependDIExpr(DIBuilder &Builder, DIExpression *DIExpr,
-                                   bool Deref, int64_t Offset) {
+static DIExpression *BuildReplacementDIExpr(DIBuilder &Builder,
+                                            DIExpression *DIExpr, bool Deref,
+                                            int Offset) {
   if (!Deref && !Offset)
     return DIExpr;
   // Create a copy of the original DIDescriptor for user variable, prepending
   // "deref" operation to a list of address elements, as new llvm.dbg.declare
   // will take a value storing address of the memory for variable, not
   // alloca itself.
-  SmallVector<uint64_t, 4> Ops;
+  SmallVector<uint64_t, 4> NewDIExpr;
   if (Deref)
-    Ops.push_back(dwarf::DW_OP_deref);
-  appendOffset(Ops, Offset);
+    DIExprAddDeref(NewDIExpr);
+  DIExprAddOffset(NewDIExpr, Offset);
   if (DIExpr)
-    Ops.append(DIExpr->elements_begin(), DIExpr->elements_end());
-  return Builder.createExpression(Ops);
+    NewDIExpr.append(DIExpr->elements_begin(), DIExpr->elements_end());
+  return Builder.createExpression(NewDIExpr);
 }
 
 bool llvm::replaceDbgDeclare(Value *Address, Value *NewAddress,
@@ -1297,7 +1302,7 @@ bool llvm::replaceDbgDeclare(Value *Addr
   auto *DIExpr = DDI->getExpression();
   assert(DIVar && "Missing variable");
 
-  DIExpr = prependDIExpr(Builder, DIExpr, Deref, Offset);
+  DIExpr = BuildReplacementDIExpr(Builder, DIExpr, Deref, Offset);
 
   // Insert llvm.dbg.declare immediately after the original alloca, and remove
   // old llvm.dbg.declare.
@@ -1329,11 +1334,11 @@ static void replaceOneDbgValueForAlloca(
   // Insert the offset immediately after the first deref.
   // We could just change the offset argument of dbg.value, but it's unsigned...
   if (Offset) {
-    SmallVector<uint64_t, 4> Ops;
-    Ops.push_back(dwarf::DW_OP_deref);
-    appendOffset(Ops, Offset);
-    Ops.append(DIExpr->elements_begin() + 1, DIExpr->elements_end());
-    DIExpr = Builder.createExpression(Ops);
+    SmallVector<uint64_t, 4> NewDIExpr;
+    DIExprAddDeref(NewDIExpr);
+    DIExprAddOffset(NewDIExpr, Offset);
+    NewDIExpr.append(DIExpr->elements_begin() + 1, DIExpr->elements_end());
+    DIExpr = Builder.createExpression(NewDIExpr);
   }
 
   Builder.insertDbgValueIntrinsic(NewAddress, DVI->getOffset(), DIVar, DIExpr,
@@ -1352,46 +1357,6 @@ void llvm::replaceDbgValueForAlloca(Allo
       }
 }
 
-void llvm::salvageDebugInfo(Instruction &I) {
-  auto MDWrap = [&](Value *V) {
-    return MetadataAsValue::get(I.getContext(), ValueAsMetadata::get(V));
-  };
-  auto &M = *I.getModule();
-  if (auto *BitCast = dyn_cast<BitCastInst>(&I))
-    findDbgValues(BitCast, [&](DbgValueInst &DVI) {
-      // Bitcasts are entirely irrelevant for debug info. Rewrite the dbg.value
-      // to use the cast's source.
-      DVI.setOperand(0, MDWrap(I.getOperand(0)));
-      DEBUG(dbgs() << "SALVAGE: " << DVI << '\n');
-    });
-  else if (auto *GEP = dyn_cast<GetElementPtrInst>(&I))
-    findDbgValues(GEP, [&](DbgValueInst &DVI) {
-      unsigned BitWidth =
-          M.getDataLayout().getPointerSizeInBits(GEP->getPointerAddressSpace());
-      APInt Offset(BitWidth, 0);
-      // Rewrite a constant GEP into a DIExpression.
-      if (GEP->accumulateConstantOffset(M.getDataLayout(), Offset)) {
-        auto *DIExpr = DVI.getExpression();
-        DIBuilder DIB(M, /*AllowUnresolved*/ false);
-        // GEP offsets are i32 and thus alwaus fit into an int64_t.
-        DIExpr = prependDIExpr(DIB, DIExpr, NoDeref, Offset.getSExtValue());
-        DVI.setOperand(0, MDWrap(I.getOperand(0)));
-        DVI.setOperand(3, MetadataAsValue::get(I.getContext(), DIExpr));
-        DEBUG(dbgs() << "SALVAGE: " << DVI << '\n');
-      }
-    });
-  else if (auto *Load = dyn_cast<LoadInst>(&I))
-    findDbgValues(Load, [&](DbgValueInst &DVI) {
-      // Rewrite the load into DW_OP_deref.
-      auto *DIExpr = DVI.getExpression();
-      DIBuilder DIB(M, /*AllowUnresolved*/ false);
-      DIExpr = prependDIExpr(DIB, DIExpr, WithDeref, 0);
-      DVI.setOperand(0, MDWrap(I.getOperand(0)));
-      DVI.setOperand(3, MetadataAsValue::get(I.getContext(), DIExpr));
-      DEBUG(dbgs() << "SALVAGE:  " << DVI << '\n');
-    });
-}
-
 unsigned llvm::removeAllNonTerminatorAndEHPadInstructions(BasicBlock *BB) {
   unsigned NumDeadInst = 0;
   // Delete the instructions backwards, as it has a reduced likelihood of

Removed: llvm/trunk/test/Transforms/InstCombine/debuginfo-dce.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/debuginfo-dce.ll?rev=297981&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/debuginfo-dce.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/debuginfo-dce.ll (removed)
@@ -1,106 +0,0 @@
-; RUN: opt -instcombine %s -S -o - | FileCheck %s
-; Verify that the eliminated instructions (bitcast, gep, load) are salvaged into
-; a DIExpression.
-;
-; Originally created from the following C source and then heavily isolated/reduced.
-;
-; struct entry {
-;   struct entry *next;
-; };
-; void scan(struct entry *queue, struct entry *end)
-; {
-;   struct entry *entry;
-;   for (entry = (struct entry *)((char *)(queue->next) - 8);
-;        &entry->next == end;
-;        entry = (struct entry *)((char *)(entry->next) - 8)) {
-;   }
-; }
-
-; ModuleID = '<stdin>'
-source_filename = "test.c"
-target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64-apple-macosx10.12.0"
-
-%struct.entry = type { %struct.entry* }
-
-; Function Attrs: nounwind ssp uwtable
-define void @salvage_load(%struct.entry** %queue) local_unnamed_addr #0 !dbg !14 {
-entry:
-  %im_not_dead = alloca %struct.entry*
-  %0 = load %struct.entry*, %struct.entry** %queue, align 8, !dbg !19
-  %1 = load %struct.entry*, %struct.entry** %queue, align 8, !dbg !19
-  call void @llvm.dbg.value(metadata %struct.entry* %1, i64 0, metadata !18, metadata !20), !dbg !19
-; CHECK: define void @salvage_load
-; CHECK-NEXT: entry:
-; CHECK-NEXT: call void @llvm.dbg.value(metadata %struct.entry** %queue, i64 0,
-; CHECK-SAME:                           metadata ![[LOAD_EXPR:[0-9]+]])
-  store %struct.entry* %1, %struct.entry** %im_not_dead, align 8
-  ret void, !dbg !21
-}
-
-; Function Attrs: nounwind ssp uwtable
-define void @salvage_bitcast(%struct.entry* %queue) local_unnamed_addr #0 !dbg !14 {
-entry:
-  %im_not_dead = alloca i8*
-  %0 = bitcast %struct.entry* %queue to i8*, !dbg !19
-  %1 = bitcast %struct.entry* %queue to i8*, !dbg !19
-  call void @llvm.dbg.value(metadata i8* %1, i64 0, metadata !18, metadata !20), !dbg !19
-; CHECK: define void @salvage_bitcast
-; CHECK-NEXT: entry:
-; CHECK-NEXT: call void @llvm.dbg.value(metadata %struct.entry* %queue, i64 0,
-; CHECK-SAME:                           metadata ![[BITCAST_EXPR:[0-9]+]])
-  store i8* %1, i8** %im_not_dead, align 8
-  ret void, !dbg !21
-}
-
-; Function Attrs: nounwind ssp uwtable
-define void @salvage_gep(%struct.entry* %queue, %struct.entry* %end) local_unnamed_addr #0 !dbg !14 {
-entry:
-  %im_not_dead = alloca %struct.entry**
-  %0 = getelementptr inbounds %struct.entry, %struct.entry* %queue, i32 -1, i32 0, !dbg !19
-  %1 = getelementptr inbounds %struct.entry, %struct.entry* %queue, i32 -1, i32 0, !dbg !19
-  call void @llvm.dbg.value(metadata %struct.entry** %1, i64 0, metadata !18, metadata !20), !dbg !19
-; CHECK: define void @salvage_gep
-; CHECK-NEXT: entry:
-; CHECK-NEXT: call void @llvm.dbg.value(metadata %struct.entry* %queue, i64 0,
-; CHECK-SAME:                           metadata ![[GEP_EXPR:[0-9]+]])
-  store %struct.entry** %1, %struct.entry*** %im_not_dead, align 8
-  ret void, !dbg !21
-}
-
-; CHECK: ![[LOAD_EXPR]] = !DIExpression(DW_OP_deref, DW_OP_plus, 0)
-; CHECK: ![[BITCAST_EXPR]] = !DIExpression(DW_OP_plus, 0)
-; CHECK: ![[GEP_EXPR]] = !DIExpression(DW_OP_minus, 8, DW_OP_plus, 0)
-
-; Function Attrs: nounwind readnone
-declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
-
-attributes #0 = { nounwind ssp uwtable }
-attributes #1 = { nounwind readnone }
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!10, !11, !12}
-!llvm.ident = !{!13}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 5.0.0 (trunk 297628) (llvm/trunk 297643)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3)
-!1 = !DIFile(filename: "test.c", directory: "/")
-!2 = !{}
-!3 = !{!4, !8}
-!4 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !5, size: 64)
-!5 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "entry", file: !1, line: 1, size: 64, elements: !6)
-!6 = !{!7}
-!7 = !DIDerivedType(tag: DW_TAG_member, name: "next", scope: !5, file: !1, line: 2, baseType: !4, size: 64)
-!8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64)
-!9 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
-!10 = !{i32 2, !"Dwarf Version", i32 4}
-!11 = !{i32 2, !"Debug Info Version", i32 3}
-!12 = !{i32 1, !"PIC Level", i32 2}
-!13 = !{!"clang version 5.0.0 (trunk 297628) (llvm/trunk 297643)"}
-!14 = distinct !DISubprogram(name: "scan", scope: !1, file: !1, line: 4, type: !15, isLocal: false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !17)
-!15 = !DISubroutineType(types: !16)
-!16 = !{null, !4, !4}
-!17 = !{!18}
-!18 = !DILocalVariable(name: "entry", scope: !14, file: !1, line: 6, type: !4)
-!19 = !DILocation(line: 6, column: 17, scope: !14)
-!20 = !DIExpression(DW_OP_plus, 0)
-!21 = !DILocation(line: 11, column: 1, scope: !14)




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