[PATCH] D23687: AMDGPU/SI: Use a better method for determining the largest pressure sets

[Matt Arsenault via llvm-commits]

arsenm added inline comments.

================
Comment at: lib/Target/AMDGPU/SIRegisterInfo.cpp:100
@@ -105,1 +99,3 @@
+  VGPRSetID = NumRegPressureSets;
+  std::map<unsigned, unsigned> PressureSetRegUnits;
 
----------------
DenseMap?

================
Comment at: lib/Target/AMDGPU/SIRegisterInfo.cpp:118
@@ +117,3 @@
+  for (unsigned i = 0; i < NumRegPressureSets; ++i) {
+    //dbgs() << getRegPressureSetName(i) << " has " << PressureSetRegUnits[i] << " units.\n";
+    if (isVGPRPressureSet(i) && PressureSetRegUnits[i] > VGPRMax) {
----------------
Leftevor debug printing

================
Comment at: lib/Target/AMDGPU/SIRegisterInfo.cpp:981
@@ +980,3 @@
+SIRegisterInfo::getRegPressureSetLimits(const MachineFunction &MF) const {
+  std::pair<unsigned, unsigned> Limits = std::make_pair(0, 0);
+
----------------
Can use the constructor parameters instead of make_pair, but this is also the default

================
Comment at: lib/Target/AMDGPU/SIRegisterInfo.cpp:987-991
@@ +986,7 @@
+
+    if (!isSGPRSet && !isVGPRSet)
+      continue;
+
+    if (isSGPRSet && isVGPRSet)
+      continue;
+
----------------
This is the same as isSGPRSet == isVGPRSet

================
Comment at: lib/Target/AMDGPU/SIRegisterInfo.cpp:1006
@@ +1005,3 @@
+SIRegisterInfo::getMaxRegPressure(ArrayRef<unsigned> SetPressure) const {
+  std::pair<unsigned, unsigned> MaxPressure = std::make_pair(0, 0);
+
----------------
Ditto

================
Comment at: lib/Target/AMDGPU/SIRegisterInfo.cpp:1008
@@ +1007,3 @@
+
+  for (unsigned i = 0; i < SetPressure.size(); i++) {
+    bool isSGPRSet = SGPRPressureSets.test(i);
----------------
Save size

================
Comment at: lib/Target/AMDGPU/SIRegisterInfo.cpp:1012-1017
@@ +1011,8 @@
+
+    if (!isSGPRSet && !isVGPRSet)
+      continue;
+
+    // Ignore the sets that contain sgprs and vgprs.
+    if (isSGPRSet && isVGPRSet)
+      continue;
+
----------------
This is the same as isSGPRSet == isVGPRSet


https://reviews.llvm.org/D23687