SDAG: Give SDDbgValues their own allocator (and reset it)

Previously `SDDbgValue`s used the general allocator that lives for all
of `SelectionDAG`.  Instead, give them their own allocator, and reset it
whenever `SDDbgInfo::clear()` is called, plugging a spiritual leak.

This drops `SelectionDAGBuilder::visitIntrinsicCall()` off of my heap
profile (was at around 2% of `llc` for codegen of `-flto -g`).  Thanks
to Pete Cooper for spotting the problem and suggesting the fix.

llvm-svn: 237998

2 files changed, 8 insertions, 3 deletions

diff --git a/llvm/include/llvm/CodeGen/SelectionDAG.h b/llvm/include/llvm/CodeGen/SelectionDAG.h
index a76843200be..89f9005b8b2 100644
--- a/llvm/include/llvm/CodeGen/SelectionDAG.h
+++ b/llvm/include/llvm/CodeGen/SelectionDAG.h
@@ -112,6 +112,7 @@ private:
 /// motion, and debug info for them is potentially useful even if the parameter
 /// is unused.  Right now only byval parameters are handled separately.
 class SDDbgInfo {
+  BumpPtrAllocator Alloc;
   SmallVector<SDDbgValue*, 32> DbgValues;
   SmallVector<SDDbgValue*, 32> ByvalParmDbgValues;
   typedef DenseMap<const SDNode*, SmallVector<SDDbgValue*, 2> > DbgValMapType;
@@ -138,8 +139,11 @@ public:
     DbgValMap.clear();
     DbgValues.clear();
     ByvalParmDbgValues.clear();
+    Alloc.Reset();
   }
 
+  BumpPtrAllocator &getAlloc() { return Alloc; }
+
   bool empty() const {
     return DbgValues.empty() && ByvalParmDbgValues.empty();
   }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index eaba9ca14eb..efd4bd9a4d8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -6055,7 +6055,8 @@ SDDbgValue *SelectionDAG::getDbgValue(MDNode *Var, MDNode *Expr, SDNode *N,
                                       DebugLoc DL, unsigned O) {
   assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) &&
          "Expected inlined-at fields to agree");
-  return new (Allocator) SDDbgValue(Var, Expr, N, R, IsIndirect, Off, DL, O);
+  return new (DbgInfo->getAlloc())
+      SDDbgValue(Var, Expr, N, R, IsIndirect, Off, DL, O);
 }
 
 /// Constant
@@ -6064,7 +6065,7 @@ SDDbgValue *SelectionDAG::getConstantDbgValue(MDNode *Var, MDNode *Expr,
                                               DebugLoc DL, unsigned O) {
   assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) &&
          "Expected inlined-at fields to agree");
-  return new (Allocator) SDDbgValue(Var, Expr, C, Off, DL, O);
+  return new (DbgInfo->getAlloc()) SDDbgValue(Var, Expr, C, Off, DL, O);
 }
 
 /// FrameIndex
@@ -6073,7 +6074,7 @@ SDDbgValue *SelectionDAG::getFrameIndexDbgValue(MDNode *Var, MDNode *Expr,
                                                 DebugLoc DL, unsigned O) {
   assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) &&
          "Expected inlined-at fields to agree");
-  return new (Allocator) SDDbgValue(Var, Expr, FI, Off, DL, O);
+  return new (DbgInfo->getAlloc()) SDDbgValue(Var, Expr, FI, Off, DL, O);
 }
 
 namespace {