Make LoadAndStorePromoter preserve debug info and create llvm.dbg.values when

promoting allocas to SSA variables. Fixes <rdar://problem/9479036>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131953 91177308-0d34-0410-b5e6-96231b3b80d8

9 files changed, 125 insertions, 27 deletions

diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h
index c9d2916821..7f99dbcf89 100644
--- a/include/llvm/Transforms/Utils/Local.h
+++ b/include/llvm/Transforms/Utils/Local.h
@@ -178,6 +178,10 @@ bool ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
 /// of llvm.dbg.value intrinsics.
 bool LowerDbgDeclare(Function &F);
 
+/// FindAllocaDbgDeclare - Finds the llvm.dbg.declare intrinsic corresponding to
+/// an alloca, if any.
+DbgDeclareInst *FindAllocaDbgDeclare(Value *V);
+
 } // End llvm namespace
 
 #endif
diff --git a/include/llvm/Transforms/Utils/SSAUpdater.h b/include/llvm/Transforms/Utils/SSAUpdater.h
index b4048b9b44..707862f588 100644
--- a/include/llvm/Transforms/Utils/SSAUpdater.h
+++ b/include/llvm/Transforms/Utils/SSAUpdater.h
@@ -21,6 +21,8 @@ namespace llvm {
   class PHINode;
   template<typename T> class SmallVectorImpl;
   template<typename T> class SSAUpdaterTraits;
+  class DbgDeclareInst;
+  class DIBuilder;
   class BumpPtrAllocator;
 
 /// SSAUpdater - This class updates SSA form for a set of values defined in
@@ -120,9 +122,12 @@ private:
 class LoadAndStorePromoter {
 protected:
   SSAUpdater &SSA;
+  DbgDeclareInst *DDI;
+  DIBuilder *&DIB;
 public:
   LoadAndStorePromoter(const SmallVectorImpl<Instruction*> &Insts,
-                       SSAUpdater &S, StringRef Name = StringRef());
+                       SSAUpdater &S, DbgDeclareInst *DDI, DIBuilder *&DIB,
+                       StringRef Name = StringRef());
   virtual ~LoadAndStorePromoter() {}
   
   /// run - This does the promotion.  Insts is a list of loads and stores to
diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp
index 93de9cf002..f706cc2a55 100644
--- a/lib/Transforms/Scalar/LICM.cpp
+++ b/lib/Transforms/Scalar/LICM.cpp
@@ -602,13 +602,14 @@ namespace {
     SmallPtrSet<Value*, 4> &PointerMustAliases;
     SmallVectorImpl<BasicBlock*> &LoopExitBlocks;
     AliasSetTracker &AST;
+    DIBuilder *DIB; // Only passed to LoadAndStorePromoter.
   public:
     LoopPromoter(Value *SP,
                  const SmallVectorImpl<Instruction*> &Insts, SSAUpdater &S,
                  SmallPtrSet<Value*, 4> &PMA,
                  SmallVectorImpl<BasicBlock*> &LEB, AliasSetTracker &ast)
-      : LoadAndStorePromoter(Insts, S), SomePtr(SP), PointerMustAliases(PMA),
-        LoopExitBlocks(LEB), AST(ast) {}
+      : LoadAndStorePromoter(Insts, S, 0, DIB), SomePtr(SP),
+        PointerMustAliases(PMA), LoopExitBlocks(LEB), AST(ast) {}
     
     virtual bool isInstInList(Instruction *I,
                               const SmallVectorImpl<Instruction*> &) const {
diff --git a/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index 5f8ab517df..ebcb88c015 100644
--- a/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -30,6 +30,7 @@
 #include "llvm/LLVMContext.h"
 #include "llvm/Module.h"
 #include "llvm/Pass.h"
+#include "llvm/Analysis/DIBuilder.h"
 #include "llvm/Analysis/Dominators.h"
 #include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/ValueTracking.h"
@@ -1051,8 +1052,9 @@ namespace {
 class AllocaPromoter : public LoadAndStorePromoter {
   AllocaInst *AI;
 public:
-  AllocaPromoter(const SmallVectorImpl<Instruction*> &Insts, SSAUpdater &S)
-    : LoadAndStorePromoter(Insts, S), AI(0) {}
+  AllocaPromoter(const SmallVectorImpl<Instruction*> &Insts, SSAUpdater &S,
+                 DbgDeclareInst *DD, DIBuilder *&DB)
+    : LoadAndStorePromoter(Insts, S, DD, DB), AI(0) {}
   
   void run(AllocaInst *AI, const SmallVectorImpl<Instruction*> &Insts) {
     // Remember which alloca we're promoting (for isInstInList).
@@ -1329,7 +1331,6 @@ static bool tryToMakeAllocaBePromotable(AllocaInst *AI, const TargetData *TD) {
   return true;
 }
 
-
 bool SROA::performPromotion(Function &F) {
   std::vector<AllocaInst*> Allocas;
   DominatorTree *DT = 0;
@@ -1340,6 +1341,7 @@ bool SROA::performPromotion(Function &F) {
 
   bool Changed = false;
   SmallVector<Instruction*, 64> Insts;
+  DIBuilder *DIB = 0;
   while (1) {
     Allocas.clear();
 
@@ -1363,8 +1365,9 @@ bool SROA::performPromotion(Function &F) {
         for (Value::use_iterator UI = AI->use_begin(), E = AI->use_end();
              UI != E; ++UI)
           Insts.push_back(cast<Instruction>(*UI));
-        
-        AllocaPromoter(Insts, SSA).run(AI, Insts);
+
+        DbgDeclareInst *DDI = FindAllocaDbgDeclare(AI);
+        AllocaPromoter(Insts, SSA, DDI, DIB).run(AI, Insts);
         Insts.clear();
       }
     }
@@ -1372,6 +1375,10 @@ bool SROA::performPromotion(Function &F) {
     Changed = true;
   }
 
+  // FIXME: Is there a better way to handle the lazy initialization of DIB
+  // so that there doesn't need to be an explicit delete?
+  delete DIB;
+
   return Changed;
 }
 
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index f5a8adacd5..3bdbaa5c09 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -20,6 +20,7 @@
 #include "llvm/Instructions.h"
 #include "llvm/Intrinsics.h"
 #include "llvm/IntrinsicInst.h"
+#include "llvm/Metadata.h"
 #include "llvm/Operator.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallPtrSet.h"
@@ -877,3 +878,15 @@ bool llvm::LowerDbgDeclare(Function &F) {
   }
   return true;
 }
+
+/// FindAllocaDbgDeclare - Finds the llvm.dbg.declare intrinsic describing the
+/// alloca 'V', if any.
+DbgDeclareInst *llvm::FindAllocaDbgDeclare(Value *V) {
+  if (MDNode *DebugNode = MDNode::getIfExists(V->getContext(), V))
+    for (Value::use_iterator UI = DebugNode->use_begin(),
+         E = DebugNode->use_end(); UI != E; ++UI)
+      if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(*UI))
+        return DDI;
+
+  return 0;
+}
diff --git a/lib/Transforms/Utils/PromoteMemoryToRegister.cpp b/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
index 50c9ae204a..a1736b931f 100644
--- a/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
+++ b/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
@@ -100,18 +100,6 @@ bool llvm::isAllocaPromotable(const AllocaInst *AI) {
   return true;
 }
 
-/// FindAllocaDbgDeclare - Finds the llvm.dbg.declare intrinsic describing the
-/// alloca 'V', if any.
-static DbgDeclareInst *FindAllocaDbgDeclare(Value *V) {
-  if (MDNode *DebugNode = MDNode::getIfExists(V->getContext(), V))
-    for (Value::use_iterator UI = DebugNode->use_begin(),
-         E = DebugNode->use_end(); UI != E; ++UI)
-      if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(*UI))
-        return DDI;
-
-  return 0;
-}
-
 namespace {
   struct AllocaInfo;
 
diff --git a/lib/Transforms/Utils/SSAUpdater.cpp b/lib/Transforms/Utils/SSAUpdater.cpp
index 2860c3e511..09f0a50cb0 100644
--- a/lib/Transforms/Utils/SSAUpdater.cpp
+++ b/lib/Transforms/Utils/SSAUpdater.cpp
@@ -14,7 +14,9 @@
 #define DEBUG_TYPE "ssaupdater"
 #include "llvm/Constants.h"
 #include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/Analysis/DIBuilder.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Support/AlignOf.h"
 #include "llvm/Support/Allocator.h"
@@ -22,6 +24,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/SSAUpdater.h"
 #include "llvm/Transforms/Utils/SSAUpdaterImpl.h"
 
@@ -355,7 +358,8 @@ Value *SSAUpdater::GetValueAtEndOfBlockInternal(BasicBlock *BB) {
 
 LoadAndStorePromoter::
 LoadAndStorePromoter(const SmallVectorImpl<Instruction*> &Insts,
-                     SSAUpdater &S, StringRef BaseName) : SSA(S) {
+                     SSAUpdater &S, DbgDeclareInst *DD, DIBuilder *&DB,
+                     StringRef BaseName) : SSA(S), DDI(DD), DIB(DB) {
   if (Insts.empty()) return;
   
   Value *SomeVal;
@@ -402,9 +406,14 @@ run(const SmallVectorImpl<Instruction*> &Insts) const {
     // single user in it, we can rewrite it trivially.
     if (BlockUses.size() == 1) {
       // If it is a store, it is a trivial def of the value in the block.
-      if (StoreInst *SI = dyn_cast<StoreInst>(User))
+      if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
+        if (DDI) {
+          if (!DIB)
+            DIB = new DIBuilder(*SI->getParent()->getParent()->getParent());
+          ConvertDebugDeclareToDebugValue(DDI, SI, *DIB);
+        }
         SSA.AddAvailableValue(BB, SI->getOperand(0));
-      else 
+      } else 
         // Otherwise it is a load, queue it to rewrite as a live-in load.
         LiveInLoads.push_back(cast<LoadInst>(User));
       BlockUses.clear();
@@ -453,12 +462,18 @@ run(const SmallVectorImpl<Instruction*> &Insts) const {
         continue;
       }
       
-      if (StoreInst *S = dyn_cast<StoreInst>(II)) {
+      if (StoreInst *SI = dyn_cast<StoreInst>(II)) {
         // If this is a store to an unrelated pointer, ignore it.
-        if (!isInstInList(S, Insts)) continue;
-        
+        if (!isInstInList(SI, Insts)) continue;
+
+        if (DDI) {
+          if (!DIB)
+            DIB = new DIBuilder(*SI->getParent()->getParent()->getParent());
+          ConvertDebugDeclareToDebugValue(DDI, SI, *DIB);
+        }
+
         // Remember that this is the active value in the block.
-        StoredValue = S->getOperand(0);
+        StoredValue = SI->getOperand(0);
       }
     }
     
@@ -513,4 +528,7 @@ run(const SmallVectorImpl<Instruction*> &Insts) const {
     instructionDeleted(User);
     User->eraseFromParent();
   }
+
+  if (DDI)
+    DDI->eraseFromParent();
 }
diff --git a/test/Transforms/ScalarRepl/debuginfo-preserved.ll b/test/Transforms/ScalarRepl/debuginfo-preserved.ll
new file mode 100644
index 0000000000..cb116ab9b3
--- /dev/null
+++ b/test/Transforms/ScalarRepl/debuginfo-preserved.ll
@@ -0,0 +1,61 @@
+; RUN: opt < %s -enable-debug-info-probe -debug-only=debuginfoprobe -scalarrepl -S | FileCheck %s
+; RUN: opt < %s -enable-debug-info-probe -debug-only=debuginfoprobe -scalarrepl-ssa -S | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-apple-macosx10.6.0"
+
+; CHECK: f
+; CHECK-NOT: llvm.dbg.declare
+; CHECK: llvm.dbg.value
+; CHECK: llvm.dbg.value
+; CHECK: llvm.dbg.value
+; CHECK: llvm.dbg.value
+; CHECK: llvm.dbg.value
+
+define i32 @f(i32 %a, i32 %b) nounwind ssp {
+entry:
+  %a.addr = alloca i32, align 4
+  %b.addr = alloca i32, align 4
+  %c = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  call void @llvm.dbg.declare(metadata !{i32* %a.addr}, metadata !6), !dbg !7
+  store i32 %b, i32* %b.addr, align 4
+  call void @llvm.dbg.declare(metadata !{i32* %b.addr}, metadata !8), !dbg !9
+  call void @llvm.dbg.declare(metadata !{i32* %c}, metadata !10), !dbg !12
+  %tmp = load i32* %a.addr, align 4, !dbg !13
+  store i32 %tmp, i32* %c, align 4, !dbg !13
+  %tmp1 = load i32* %a.addr, align 4, !dbg !14
+  %tmp2 = load i32* %b.addr, align 4, !dbg !14
+  %add = add nsw i32 %tmp1, %tmp2, !dbg !14
+  store i32 %add, i32* %a.addr, align 4, !dbg !14
+  %tmp3 = load i32* %c, align 4, !dbg !15
+  %tmp4 = load i32* %b.addr, align 4, !dbg !15
+  %sub = sub nsw i32 %tmp3, %tmp4, !dbg !15
+  store i32 %sub, i32* %b.addr, align 4, !dbg !15
+  %tmp5 = load i32* %a.addr, align 4, !dbg !16
+  %tmp6 = load i32* %b.addr, align 4, !dbg !16
+  %add7 = add nsw i32 %tmp5, %tmp6, !dbg !16
+  ret i32 %add7, !dbg !16
+}
+
+declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
+
+!llvm.dbg.cu = !{!0}
+!llvm.dbg.sp = !{!1}
+
+!0 = metadata !{i32 589841, i32 0, i32 12, metadata !"/d/j/debug-test.c", metadata !"/Volumes/Data/b", metadata !"clang version 3.0 (trunk 131941)", i1 true, i1 false, metadata !"", i32 0} ; [ DW_TAG_compile_unit ]
+!1 = metadata !{i32 589870, i32 0, metadata !2, metadata !"f", metadata !"f", metadata !"", metadata !2, i32 1, metadata !3, i1 false, i1 true, i32 0, i32 0, i32 0, i32 256, i1 false, i32 (i32, i32)* @f, null, null} ; [ DW_TAG_subprogram ]
+!2 = metadata !{i32 589865, metadata !"/d/j/debug-test.c", metadata !"/Volumes/Data/b", metadata !0} ; [ DW_TAG_file_type ]
+!3 = metadata !{i32 589845, metadata !2, metadata !"", metadata !2, i32 0, i64 0, i64 0, i32 0, i32 0, i32 0, metadata !4, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 589860, metadata !0, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
+!6 = metadata !{i32 590081, metadata !1, metadata !"a", metadata !2, i32 16777217, metadata !5, i32 0} ; [ DW_TAG_arg_variable ]
+!7 = metadata !{i32 1, i32 11, metadata !1, null}
+!8 = metadata !{i32 590081, metadata !1, metadata !"b", metadata !2, i32 33554433, metadata !5, i32 0} ; [ DW_TAG_arg_variable ]
+!9 = metadata !{i32 1, i32 18, metadata !1, null}
+!10 = metadata !{i32 590080, metadata !11, metadata !"c", metadata !2, i32 2, metadata !5, i32 0} ; [ DW_TAG_auto_variable ]
+!11 = metadata !{i32 589835, metadata !1, i32 1, i32 21, metadata !2, i32 0} ; [ DW_TAG_lexical_block ]
+!12 = metadata !{i32 2, i32 9, metadata !11, null}
+!13 = metadata !{i32 2, i32 14, metadata !11, null}
+!14 = metadata !{i32 3, i32 5, metadata !11, null}
+!15 = metadata !{i32 4, i32 5, metadata !11, null}
+!16 = metadata !{i32 5, i32 5, metadata !11, null}
diff --git a/test/Transforms/ScalarRepl/debuginfo.ll b/test/Transforms/ScalarRepl/debuginfo.ll
index 6b8422cefa..ae2c6cc8f6 100644
--- a/test/Transforms/ScalarRepl/debuginfo.ll
+++ b/test/Transforms/ScalarRepl/debuginfo.ll
@@ -1,4 +1,5 @@
 ; RUN: opt < %s -scalarrepl -S | not grep alloca
+; RUN: opt < %s -scalarrepl-ssa -S | not grep alloca
 target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64"
 	%llvm.dbg.anchor.type = type { i32, i32 }
 	%llvm.dbg.basictype.type = type { i32, { }*, i8*, { }*, i32, i64, i64, i64, i32, i32 }