[llvm] [AMDGPU][Scheduler] Scoring system for rematerialization candidates (PR #153092)

[Matt Arsenault via llvm-commits]

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@@ -1089,33 +1102,224 @@ bool ClusteredLowOccStage::initGCNSchedStage() {
 #define REMAT_PREFIX "[PreRARemat] "
 #define REMAT_DEBUG(X) LLVM_DEBUG(dbgs() << REMAT_PREFIX; X;)
 
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void PreRARematStage::printTargetRegions(bool PrintAll) const {
+  if (PrintAll) {
+    for (auto [I, Target] : enumerate(RPTargets))
+      REMAT_DEBUG(dbgs() << "  [" << I << "] " << Target << '\n');
+    return;
+  }
+  if (TargetRegions.none()) {
+    REMAT_DEBUG(dbgs() << "No target regions\n");
+    return;
+  }
+  REMAT_DEBUG(dbgs() << "Target regions:\n");
+  for (unsigned I : TargetRegions.set_bits())
+    REMAT_DEBUG(dbgs() << "  [" << I << "] " << RPTargets[I] << '\n');
+}
+
+void PreRARematStage::RematReg::print(
+    const DenseMap<MachineInstr *, unsigned> &MIRegion) const {
+  REMAT_DEBUG(dbgs() << "  [" << MIRegion.at(DefMI) << "] " << *DefMI);
+  REMAT_DEBUG(dbgs() << "    -> used in [" << UseRegion << "] " << *UseMI);
+  const unsigned NumRegions = Live.size();
+  REMAT_DEBUG(dbgs() << "    Guaranteed RP reduction in:");
+  for (unsigned I = 0; I < NumRegions; ++I) {
+    if (isBeneficialRegion(I))
+      dbgs() << " [" << I << "]";
+  }
+  dbgs() << '\n';
+  REMAT_DEBUG(dbgs() << "    Possible RP reduction in:");
+  for (unsigned I = 0; I < NumRegions; ++I) {
+    if (isMaybeBeneficialRegion(I))
+      dbgs() << " [" << I << "]";
+  }
+  dbgs() << '\n';
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arsenm wrote:

Ditto, REMAT_DEBUG redundant with the ones at the use points 

https://github.com/llvm/llvm-project/pull/153092