[PATCH] D111799: [DebugInfo][InstrRef] Improve compile-time performance by handling a single variable at a time

[Orlando Cazalet-Hyams via Phabricator via llvm-commits]

Orlando accepted this revision.
Orlando added a comment.
This revision is now accepted and ready to land.

LGTM!



================
Comment at: llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp:2044
       return None;
-
-    auto It = LiveOutMap->second->find(Var);
-    if (It == LiveOutMap->second->end())
-      // There's no value recorded for this variable in this predecessor,
-      // leave an empty set of locations.
-      return None;
-
-    const DbgValue &OutVal = It->second;
+    DbgValue &OutVal = *OutValIt->second;
 
----------------
Can this no longer be const?


================
Comment at: llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp:2183
+  // here, or b) we eliminated the PHI that was here. If so, we can just
+  // propagate in the first parents incoming value.
+  if (LiveIn.Kind != DbgValue::VPHI || LiveIn.BlockNo != MBB.getNumber()) {
----------------
nit: `parents` -> `parent's`, while you're nearby.


================
Comment at: llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.cpp:2441
+
+        // If this blocks live-in value is a VPHI, try to pick a machine-value
+        // for it. This makes the machine-value available and propagated
----------------
nit: blocks -> block's


================
Comment at: llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.h:649-650
 
   /// Live in/out structure for the variable values: a per-block map of
   /// variables to their values. XXX, better name?
+  using LiveIdxT = DenseMap<const MachineBasicBlock *, DbgValue *>;
----------------
The part of the comment after the colon seems redundant now?


================
Comment at: llvm/lib/CodeGen/LiveDebugValues/InstrRefBasedImpl.h:874
   ///          or PHI elimination.
   bool vlocJoin(MachineBasicBlock &MBB, LiveIdxT &VLOCOutLocs,
                 SmallPtrSet<const MachineBasicBlock *, 8> &InScopeBlocks,
----------------
Doc-comment is out of date.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D111799/new/

https://reviews.llvm.org/D111799