[llvm] [TableGen] Add some -time-phases support in CodeGenRegisters (PR #149309)

[Jay Foad via llvm-commits]

https://github.com/jayfoad created https://github.com/llvm/llvm-project/pull/149309

None

>From 524ba5d33e17c193cea3d055b7b15a4830f01e80 Mon Sep 17 00:00:00 2001
From: Jay Foad <jay.foad at amd.com>
Date: Wed, 16 Jul 2025 16:07:35 +0100
Subject: [PATCH] [TableGen] Add some -time-phases support in CodeGenRegisters

---
 llvm/utils/TableGen/Common/CodeGenRegisters.cpp | 11 ++++++++++-
 llvm/utils/TableGen/Common/CodeGenRegisters.h   |  2 ++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/llvm/utils/TableGen/Common/CodeGenRegisters.cpp b/llvm/utils/TableGen/Common/CodeGenRegisters.cpp
index 28b542f09e8c0..1730139ec0712 100644
--- a/llvm/utils/TableGen/Common/CodeGenRegisters.cpp
+++ b/llvm/utils/TableGen/Common/CodeGenRegisters.cpp
@@ -30,6 +30,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
+#include "llvm/TableGen/TGTimer.h"
 #include <algorithm>
 #include <cassert>
 #include <cstdint>
@@ -1130,7 +1131,7 @@ CodeGenRegisterCategory::CodeGenRegisterCategory(CodeGenRegBank &RegBank,
 
 CodeGenRegBank::CodeGenRegBank(const RecordKeeper &Records,
                                const CodeGenHwModes &Modes)
-    : CGH(Modes) {
+    : Records(Records), CGH(Modes) {
   // Configure register Sets to understand register classes and tuples.
   Sets.addFieldExpander("RegisterClass", "MemberList");
   Sets.addFieldExpander("CalleeSavedRegs", "SaveList");
@@ -2202,7 +2203,9 @@ void CodeGenRegBank::computeDerivedInfo() {
 
   // Compute a weight for each register unit created during getSubRegs.
   // This may create adopted register units (with unit # >= NumNativeRegUnits).
+  Records.getTimer().startTimer("Compute reg unit weights");
   computeRegUnitWeights();
+  Records.getTimer().stopTimer();
 
   // Compute a unique set of RegUnitSets. One for each RegClass and inferred
   // supersets for the union of overlapping sets.
@@ -2450,6 +2453,8 @@ void CodeGenRegBank::computeInferredRegisterClasses() {
   // added.
   auto FirstNewRC = std::prev(RegClasses.end());
 
+  Records.getTimer().startTimer("Compute inferred register classes");
+
   // Visit all register classes, including the ones being added by the loop.
   // Watch out for iterator invalidation here.
   for (auto I = RegClasses.begin(), E = RegClasses.end(); I != E; ++I) {
@@ -2481,6 +2486,8 @@ void CodeGenRegBank::computeInferredRegisterClasses() {
     }
   }
 
+  Records.getTimer().startTimer("Extend super-register classes");
+
   // Compute the transitive closure for super-register classes.
   //
   // By iterating over sub-register indices in topological order, we only ever
@@ -2491,6 +2498,8 @@ void CodeGenRegBank::computeInferredRegisterClasses() {
     for (CodeGenRegisterClass &SubRC : RegClasses)
       SubRC.extendSuperRegClasses(SubIdx);
   }
+
+  Records.getTimer().stopTimer();
 }
 
 /// getRegisterClassForRegister - Find the register class that contains the
diff --git a/llvm/utils/TableGen/Common/CodeGenRegisters.h b/llvm/utils/TableGen/Common/CodeGenRegisters.h
index 5e6fff0f775ea..81aa663b8f11e 100644
--- a/llvm/utils/TableGen/Common/CodeGenRegisters.h
+++ b/llvm/utils/TableGen/Common/CodeGenRegisters.h
@@ -607,6 +607,8 @@ typedef SmallVector<unsigned, 16> TopoSigId;
 // CodeGenRegBank - Represent a target's registers and the relations between
 // them.
 class CodeGenRegBank {
+  const RecordKeeper &Records;
+
   SetTheory Sets;
 
   const CodeGenHwModes &CGH;