[SelectionDAG] Consolidate (t|T)ransferDbgValues methods, NFC (reapply)

TransferDbgValues (capital 'T') is wired into ReplaceAllUsesWith, and
transferDbgValues (lowercase 't') is used elsewhere (e.g in Legalize).

Both functions should be doing the exact same thing. This patch
consolidates the logic into one place.

This was reverted in r318455 because some newly introduced asserts,
which I thought were NFC, were firing. I filed PR35338. For now I've
weakened the asserts.

Testing: check-llvm, check-clang, and a stage2 Rel+Deb build of clang

Differential Revision: https://reviews.llvm.org/D40104

llvm-svn: 318498

diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h
index bb806c0..ba3511d 100644 (file)
--- a/llvm/include/llvm/CodeGen/SelectionDAG.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAG.h
@@ -1195,9 +1195,10 @@ public:
                                     unsigned O);
 
   /// Transfer debug values from one node to another, while optionally
-  /// generating fragment expressions for split-up values.
+  /// generating fragment expressions for split-up values. If \p InvalidateDbg
+  /// is set, debug values are invalidated after they are transferred.
   void transferDbgValues(SDValue From, SDValue To, unsigned OffsetInBits = 0,
-                         unsigned SizeInBits = 0);
+                         unsigned SizeInBits = 0, bool InvalidateDbg = true);
 
   /// Remove the specified node from the system. If any of its
   /// operands then becomes dead, remove them as well. Inform UpdateListener
@@ -1279,10 +1280,6 @@ public:
     return DbgInfo->getSDDbgValues(SD);
   }
 
-private:
-  /// Transfer SDDbgValues. Called via ReplaceAllUses{OfValue}?With
-  void TransferDbgValues(SDValue From, SDValue To);
-
 public:
   /// Return true if there are any SDDbgValue nodes associated
   /// with this SelectionDAG.

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
index 053d562..73e2996 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
@@ -845,13 +845,14 @@ void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo,
   AnalyzeNewValue(Lo);
   AnalyzeNewValue(Hi);
 
-  // Transfer debug values.
+  // Transfer debug values. Don't invalidate the source debug value until it's
+  // been transferred to the high and low bits.
   if (DAG.getDataLayout().isBigEndian()) {
-    DAG.transferDbgValues(Op, Hi, 0, Hi.getValueSizeInBits());
+    DAG.transferDbgValues(Op, Hi, 0, Hi.getValueSizeInBits(), false);
     DAG.transferDbgValues(Op, Lo, Hi.getValueSizeInBits(),
                           Lo.getValueSizeInBits());
   } else {
-    DAG.transferDbgValues(Op, Lo, 0, Lo.getValueSizeInBits());
+    DAG.transferDbgValues(Op, Lo, 0, Lo.getValueSizeInBits(), false);
     DAG.transferDbgValues(Op, Hi, Lo.getValueSizeInBits(),
                           Hi.getValueSizeInBits());
   }

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index fe5a156..805732c 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -7027,16 +7027,31 @@ SDDbgValue *SelectionDAG::getFrameIndexDbgValue(DIVariable *Var,
 }
 
 void SelectionDAG::transferDbgValues(SDValue From, SDValue To,
-                                     unsigned OffsetInBits,
-                                     unsigned SizeInBits) {
+                                     unsigned OffsetInBits, unsigned SizeInBits,
+                                     bool InvalidateDbg) {
   SDNode *FromNode = From.getNode();
   SDNode *ToNode = To.getNode();
-  assert(FromNode != ToNode);
+  assert(FromNode && ToNode && "Can't modify dbg values");
+
+  // PR35338
+  // TODO: assert(From != To && "Redundant dbg value transfer");
+  // TODO: assert(FromNode != ToNode && "Intranode dbg value transfer");
+  if (From == To || FromNode == ToNode)
+    return;
+
+  if (!FromNode->getHasDebugValue())
+    return;
 
   SmallVector<SDDbgValue *, 2> ClonedDVs;
   for (SDDbgValue *Dbg : GetDbgValues(FromNode)) {
-    if (Dbg->getKind() != SDDbgValue::SDNODE)
-      break;
+    if (Dbg->getKind() != SDDbgValue::SDNODE || Dbg->isInvalidated())
+      continue;
+
+    // TODO: assert(!Dbg->isInvalidated() && "Transfer of invalid dbg value");
+
+    // Just transfer the dbg value attached to From.
+    if (Dbg->getResNo() != From.getResNo())
+      continue;
 
     DIVariable *Var = Dbg->getVariable();
     auto *Expr = Dbg->getExpression();
@@ -7059,7 +7074,9 @@ void SelectionDAG::transferDbgValues(SDValue From, SDValue To,
         getDbgValue(Var, Expr, ToNode, To.getResNo(), Dbg->isIndirect(),
                     Dbg->getDebugLoc(), Dbg->getOrder());
     ClonedDVs.push_back(Clone);
-    Dbg->setIsInvalidated();
+
+    if (InvalidateDbg)
+      Dbg->setIsInvalidated();
   }
 
   for (SDDbgValue *Dbg : ClonedDVs)
@@ -7137,7 +7154,7 @@ void SelectionDAG::ReplaceAllUsesWith(SDValue FromN, SDValue To) {
   assert(From != To.getNode() && "Cannot replace uses of with self");
 
   // Preserve Debug Values
-  TransferDbgValues(FromN, To);
+  transferDbgValues(FromN, To);
 
   // Iterate over all the existing uses of From. New uses will be added
   // to the beginning of the use list, which we avoid visiting.
@@ -7196,7 +7213,7 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From, SDNode *To) {
   for (unsigned i = 0, e = From->getNumValues(); i != e; ++i)
     if (From->hasAnyUseOfValue(i)) {
       assert((i < To->getNumValues()) && "Invalid To location");
-      TransferDbgValues(SDValue(From, i), SDValue(To, i));
+      transferDbgValues(SDValue(From, i), SDValue(To, i));
     }
 
   // Iterate over just the existing users of From. See the comments in
@@ -7240,7 +7257,7 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From, const SDValue *To) {
 
   // Preserve Debug Info.
   for (unsigned i = 0, e = From->getNumValues(); i != e; ++i)
-    TransferDbgValues(SDValue(From, i), *To);
+    transferDbgValues(SDValue(From, i), *To);
 
   // Iterate over just the existing users of From. See the comments in
   // the ReplaceAllUsesWith above.
@@ -7287,7 +7304,7 @@ void SelectionDAG::ReplaceAllUsesOfValueWith(SDValue From, SDValue To){
   }
 
   // Preserve Debug Info.
-  TransferDbgValues(From, To);
+  transferDbgValues(From, To);
 
   // Iterate over just the existing users of From. See the comments in
   // the ReplaceAllUsesWith above.
@@ -7365,7 +7382,7 @@ void SelectionDAG::ReplaceAllUsesOfValuesWith(const SDValue *From,
   if (Num == 1)
     return ReplaceAllUsesOfValueWith(*From, *To);
 
-  TransferDbgValues(*From, *To);
+  transferDbgValues(*From, *To);
 
   // Read up all the uses and make records of them. This helps
   // processing new uses that are introduced during the
@@ -7514,31 +7531,6 @@ void SelectionDAG::AddDbgValue(SDDbgValue *DB, SDNode *SD, bool isParameter) {
   DbgInfo->add(DB, SD, isParameter);
 }
 
-/// Transfer SDDbgValues. Called in replace nodes.
-void SelectionDAG::TransferDbgValues(SDValue From, SDValue To) {
-  if (From == To || !From.getNode()->getHasDebugValue())
-    return;
-  SDNode *FromNode = From.getNode();
-  SDNode *ToNode = To.getNode();
-  SmallVector<SDDbgValue *, 2> ClonedDVs;
-  for (auto *Dbg : GetDbgValues(FromNode)) {
-    // Only add Dbgvalues attached to same ResNo.
-    if (Dbg->getKind() == SDDbgValue::SDNODE &&
-        Dbg->getSDNode() == From.getNode() &&
-        Dbg->getResNo() == From.getResNo() && !Dbg->isInvalidated()) {
-      assert(FromNode != ToNode &&
-             "Should not transfer Debug Values intranode");
-      SDDbgValue *Clone = getDbgValue(Dbg->getVariable(), Dbg->getExpression(),
-                                      ToNode, To.getResNo(), Dbg->isIndirect(),
-                                      Dbg->getDebugLoc(), Dbg->getOrder());
-      ClonedDVs.push_back(Clone);
-      Dbg->setIsInvalidated();
-    }
-  }
-  for (SDDbgValue *I : ClonedDVs)
-    AddDbgValue(I, ToNode, false);
-}
-
 SDValue SelectionDAG::makeEquivalentMemoryOrdering(LoadSDNode *OldLoad,
                                                    SDValue NewMemOp) {
   assert(isa<MemSDNode>(NewMemOp.getNode()) && "Expected a memop node");