[llvm] 1cf9092 - [MISched] Small debug improvements (#125072)

[via llvm-commits]

Author: Cullen Rhodes
Date: 2025-02-05T09:14:51Z
New Revision: 1cf909208e509aedbd63edb5af0b96f85d5ae28b

URL: https://github.com/llvm/llvm-project/commit/1cf909208e509aedbd63edb5af0b96f85d5ae28b
DIFF: https://github.com/llvm/llvm-project/commit/1cf909208e509aedbd63edb5af0b96f85d5ae28b.diff

LOG: [MISched] Small debug improvements (#125072)

Changes:
1. Fix inconsistencies in register pressure set printing. "Max Pressure"
   printing is inconsistent with "Bottom Pressure" and "Top Pressure".
   For the former, register class begins on the same line vs newline for
   latter. Also for the former, the first register class is on the same
   line, but subsequent register classes are newline separated. That's
   removed so all are on the same line.

   Before:
     Max Pressure: FPR8=1
     GPR32=14
     Top Pressure:
     GPR32=2
     Bottom Pressure:
     FPR8=7
     GPR32=17

   After:
     Max Pressure: FPR8=1 GPR32=14
     Top Pressure: GPR32=2
     Bottom Pressure: FPR8=7 GPR32=17

2. After scheduling an instruction, don't print pressure diff if there
   isn't one. Also s/UpdateRegP/UpdateRegPressure. E.g.,

   Before:
     UpdateRegP: SU(3) %0:gpr64common = ADDXrr %58:gpr64common, gpr64
                 to
     UpdateRegP: SU(4) %393:gpr64sp = ADDXri %58:gpr64common, 390, 12
                 to GPR32 -1

   After:
     UpdateRegPressure: SU(4) %393:gpr64sp = ADDXri %58:gpr64common, 12
                        to GPR32 -1
3. Don't print excess pressure sets if there are none.

Added: 
    

Modified: 
    llvm/lib/CodeGen/MachineScheduler.cpp
    llvm/lib/CodeGen/RegisterPressure.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index de771452254147..df90077b15f331 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -1414,9 +1414,9 @@ void ScheduleDAGMILive::initRegPressure() {
     updatePressureDiffs(LiveUses);
   }
 
-  LLVM_DEBUG(dbgs() << "Top Pressure:\n";
+  LLVM_DEBUG(dbgs() << "Top Pressure: ";
              dumpRegSetPressure(TopRPTracker.getRegSetPressureAtPos(), TRI);
-             dbgs() << "Bottom Pressure:\n";
+             dbgs() << "Bottom Pressure: ";
              dumpRegSetPressure(BotRPTracker.getRegSetPressureAtPos(), TRI););
 
   assert((BotRPTracker.getPos() == RegionEnd ||
@@ -1437,11 +1437,14 @@ void ScheduleDAGMILive::initRegPressure() {
       RegionCriticalPSets.push_back(PressureChange(i));
     }
   }
-  LLVM_DEBUG(dbgs() << "Excess PSets: ";
-             for (const PressureChange &RCPS
-                  : RegionCriticalPSets) dbgs()
-             << TRI->getRegPressureSetName(RCPS.getPSet()) << " ";
-             dbgs() << "\n");
+  LLVM_DEBUG({
+    if (RegionCriticalPSets.size() > 0) {
+      dbgs() << "Excess PSets: ";
+      for (const PressureChange &RCPS : RegionCriticalPSets)
+        dbgs() << TRI->getRegPressureSetName(RCPS.getPSet()) << " ";
+      dbgs() << "\n";
+    }
+  });
 }
 
 void ScheduleDAGMILive::
@@ -1495,10 +1498,14 @@ void ScheduleDAGMILive::updatePressureDiffs(ArrayRef<VRegMaskOrUnit> LiveUses) {
 
         PressureDiff &PDiff = getPressureDiff(&SU);
         PDiff.addPressureChange(Reg, Decrement, &MRI);
-        LLVM_DEBUG(dbgs() << "  UpdateRegP: SU(" << SU.NodeNum << ") "
-                          << printReg(Reg, TRI) << ':'
-                          << PrintLaneMask(P.LaneMask) << ' ' << *SU.getInstr();
-                   dbgs() << "              to "; PDiff.dump(*TRI););
+        if (llvm::any_of(PDiff, [](const PressureChange &Change) {
+              return Change.isValid();
+            }))
+          LLVM_DEBUG(dbgs()
+                         << "  UpdateRegPressure: SU(" << SU.NodeNum << ") "
+                         << printReg(Reg, TRI) << ':'
+                         << PrintLaneMask(P.LaneMask) << ' ' << *SU.getInstr();
+                     dbgs() << "                     to "; PDiff.dump(*TRI););
       }
     } else {
       assert(P.LaneMask.any());
@@ -1530,9 +1537,13 @@ void ScheduleDAGMILive::updatePressureDiffs(ArrayRef<VRegMaskOrUnit> LiveUses) {
           if (LRQ.valueIn() == VNI) {
             PressureDiff &PDiff = getPressureDiff(SU);
             PDiff.addPressureChange(Reg, true, &MRI);
-            LLVM_DEBUG(dbgs() << "  UpdateRegP: SU(" << SU->NodeNum << ") "
-                              << *SU->getInstr();
-                       dbgs() << "              to "; PDiff.dump(*TRI););
+            if (llvm::any_of(PDiff, [](const PressureChange &Change) {
+                  return Change.isValid();
+                }))
+              LLVM_DEBUG(dbgs() << "  UpdateRegPressure: SU(" << SU->NodeNum
+                                << ") " << *SU->getInstr();
+                         dbgs() << "                     to ";
+                         PDiff.dump(*TRI););
           }
         }
       }
@@ -1792,7 +1803,7 @@ void ScheduleDAGMILive::scheduleMI(SUnit *SU, bool IsTopNode) {
 
       TopRPTracker.advance(RegOpers);
       assert(TopRPTracker.getPos() == CurrentTop && "out of sync");
-      LLVM_DEBUG(dbgs() << "Top Pressure:\n"; dumpRegSetPressure(
+      LLVM_DEBUG(dbgs() << "Top Pressure: "; dumpRegSetPressure(
                      TopRPTracker.getRegSetPressureAtPos(), TRI););
 
       updateScheduledPressure(SU, TopRPTracker.getPressure().MaxSetPressure);
@@ -1830,7 +1841,7 @@ void ScheduleDAGMILive::scheduleMI(SUnit *SU, bool IsTopNode) {
       SmallVector<VRegMaskOrUnit, 8> LiveUses;
       BotRPTracker.recede(RegOpers, &LiveUses);
       assert(BotRPTracker.getPos() == CurrentBottom && "out of sync");
-      LLVM_DEBUG(dbgs() << "Bottom Pressure:\n"; dumpRegSetPressure(
+      LLVM_DEBUG(dbgs() << "Bottom Pressure: "; dumpRegSetPressure(
                      BotRPTracker.getRegSetPressureAtPos(), TRI););
 
       updateScheduledPressure(SU, BotRPTracker.getPressure().MaxSetPressure);

diff  --git a/llvm/lib/CodeGen/RegisterPressure.cpp b/llvm/lib/CodeGen/RegisterPressure.cpp
index e8e6db1e3b3bd1..ca51b670b46cce 100644
--- a/llvm/lib/CodeGen/RegisterPressure.cpp
+++ b/llvm/lib/CodeGen/RegisterPressure.cpp
@@ -79,15 +79,12 @@ static void decreaseSetPressure(std::vector<unsigned> &CurrSetPressure,
 LLVM_DUMP_METHOD
 void llvm::dumpRegSetPressure(ArrayRef<unsigned> SetPressure,
                               const TargetRegisterInfo *TRI) {
-  bool Empty = true;
   for (unsigned i = 0, e = SetPressure.size(); i < e; ++i) {
     if (SetPressure[i] != 0) {
-      dbgs() << TRI->getRegPressureSetName(i) << "=" << SetPressure[i] << '\n';
-      Empty = false;
+      dbgs() << TRI->getRegPressureSetName(i) << "=" << SetPressure[i] << ' ';
     }
   }
-  if (Empty)
-    dbgs() << "\n";
+  dbgs() << "\n";
 }
 
 LLVM_DUMP_METHOD