[PATCH] D136927: [AMDGPU] Fix GCNDownwardRPTracker::advanceBeforeNext at the end of MBB

[Valery Pykhtin via Phabricator via llvm-commits]

vpykhtin updated this revision to Diff 472263.
vpykhtin added a comment.

restored bool return value for advanceBeforeNext, added debug instr skipping


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D136927/new/

https://reviews.llvm.org/D136927

Files:
  llvm/lib/Target/AMDGPU/GCNRegPressure.cpp
  llvm/lib/Target/AMDGPU/GCNRegPressure.h
  llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp


Index: llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp
+++ llvm/lib/Target/AMDGPU/GCNSchedStrategy.cpp
@@ -538,7 +538,6 @@
       RPTracker.advanceToNext();
       RPTracker.advance(MBB->end());
     }
-    RPTracker.reset(*OnlySucc->begin(), &RPTracker.getLiveRegs());
     RPTracker.advanceBeforeNext();
     MBBLiveIns[OnlySucc] = RPTracker.moveLiveRegs();
   }
Index: llvm/lib/Target/AMDGPU/GCNRegPressure.h
===================================================================
--- llvm/lib/Target/AMDGPU/GCNRegPressure.h
+++ llvm/lib/Target/AMDGPU/GCNRegPressure.h
@@ -172,8 +172,8 @@
   // Returns false if block is empty except debug values.
   bool reset(const MachineInstr &MI, const LiveRegSet *LiveRegs = nullptr);
 
-  // Move to the state right before the next MI. Returns false if reached
-  // end of the block.
+  // Move to the state right before the next MI or after the end of MBB.
+  // Returns false if reached end of the block.
   bool advanceBeforeNext();
 
   // Move to the state at the MI, advanceBeforeNext has to be called first.
Index: llvm/lib/Target/AMDGPU/GCNRegPressure.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/GCNRegPressure.cpp
+++ llvm/lib/Target/AMDGPU/GCNRegPressure.cpp
@@ -325,12 +325,12 @@
 
 bool GCNDownwardRPTracker::advanceBeforeNext() {
   assert(MRI && "call reset first");
+  if (!LastTrackedMI)
+    return NextMI == MBBEnd;
 
-  NextMI = skipDebugInstructionsForward(NextMI, MBBEnd);
-  if (NextMI == MBBEnd)
-    return false;
-
-  SlotIndex SI = LIS.getInstructionIndex(*NextMI).getBaseIndex();
+  SlotIndex SI = NextMI == MBBEnd
+                     ? LIS.getInstructionIndex(*LastTrackedMI).getDeadSlot()
+                     : LIS.getInstructionIndex(*NextMI).getBaseIndex();
   assert(SI.isValid());
 
   // Remove dead registers or mask bits.
@@ -355,7 +355,9 @@
 
   MaxPressure = max(MaxPressure, CurPressure);
 
-  return true;
+  LastTrackedMI = nullptr;
+
+  return NextMI == MBBEnd;
 }
 
 void GCNDownwardRPTracker::advanceToNext() {
@@ -379,9 +381,9 @@
 }
 
 bool GCNDownwardRPTracker::advance() {
-  // If we have just called reset live set is actual.
-  if ((NextMI == MBBEnd) || (LastTrackedMI && !advanceBeforeNext()))
+  if (NextMI == MBBEnd)
     return false;
+  advanceBeforeNext();
   advanceToNext();
   return true;
 }


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