[NFC] Make AMDGPUCombinerHelper methods const

[paulhuggett]

(This replaces #121740. Sorry for wasting your time.)

This is a follow-up to a previous commit (ee7ca0d) which eliminated several "TODO: make CombinerHelper methods const" remarks. As promised in that ealier commit, this change completes the set by also making the methods of AMDGPUCombinerHelper const so that the Helper member of AMDGPUPreLegalizerCombinerImpl can be const rather than explicitly mutable.

[llvmbot]

@llvm/pr-subscribers-backend-amdgpu

Author: Paul Bowen-Huggett (paulhuggett)

Changes

(This replaces #121740. Sorry for wasting your time.)

This is a follow-up to a previous commit (ee7ca0d) which eliminated several "TODO: make CombinerHelper methods const" remarks. As promised in that ealier commit, this change completes the set by also making the methods of AMDGPUCombinerHelper const so that the Helper member of AMDGPUPreLegalizerCombinerImpl can be const rather than explicitly mutable.

---

Full diff: https://github.com/llvm/llvm-project/pull/121903.diff

2 Files Affected:

• (modified) llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.cpp (+5-5)
• (modified) llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.h (+5-5)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.cpp b/llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.cpp
index f6f9f4bc0fb1bb..46194ab46ff6a7 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.cpp
@@ -197,7 +197,7 @@ static unsigned inverseMinMax(unsigned Opc) {
 }
 
 bool AMDGPUCombinerHelper::matchFoldableFneg(MachineInstr &MI,
-                                             MachineInstr *&MatchInfo) {
+                                             MachineInstr *&MatchInfo) const {
   Register Src = MI.getOperand(1).getReg();
   MatchInfo = MRI.getVRegDef(Src);
 
@@ -266,7 +266,7 @@ bool AMDGPUCombinerHelper::matchFoldableFneg(MachineInstr &MI,
 }
 
 void AMDGPUCombinerHelper::applyFoldableFneg(MachineInstr &MI,
-                                             MachineInstr *&MatchInfo) {
+                                             MachineInstr *&MatchInfo) const {
   // Transform:
   // %A = inst %Op1, ...
   // %B = fneg %A
@@ -425,7 +425,7 @@ static bool isFPExtFromF16OrConst(const MachineRegisterInfo &MRI,
 bool AMDGPUCombinerHelper::matchExpandPromotedF16FMed3(MachineInstr &MI,
                                                        Register Src0,
                                                        Register Src1,
-                                                       Register Src2) {
+                                                       Register Src2) const {
   assert(MI.getOpcode() == TargetOpcode::G_FPTRUNC);
   Register SrcReg = MI.getOperand(1).getReg();
   if (!MRI.hasOneNonDBGUse(SrcReg) || MRI.getType(SrcReg) != LLT::scalar(32))
@@ -438,7 +438,7 @@ bool AMDGPUCombinerHelper::matchExpandPromotedF16FMed3(MachineInstr &MI,
 void AMDGPUCombinerHelper::applyExpandPromotedF16FMed3(MachineInstr &MI,
                                                        Register Src0,
                                                        Register Src1,
-                                                       Register Src2) {
+                                                       Register Src2) const {
   // We expect fptrunc (fpext x) to fold out, and to constant fold any constant
   // sources.
   Src0 = Builder.buildFPTrunc(LLT::scalar(16), Src0).getReg(0);
@@ -455,7 +455,7 @@ void AMDGPUCombinerHelper::applyExpandPromotedF16FMed3(MachineInstr &MI,
 
 bool AMDGPUCombinerHelper::matchCombineFmulWithSelectToFldexp(
     MachineInstr &MI, MachineInstr &Sel,
-    std::function<void(MachineIRBuilder &)> &MatchInfo) {
+    std::function<void(MachineIRBuilder &)> &MatchInfo) const {
   assert(MI.getOpcode() == TargetOpcode::G_FMUL);
   assert(Sel.getOpcode() == TargetOpcode::G_SELECT);
   assert(MI.getOperand(2).getReg() == Sel.getOperand(0).getReg());
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.h b/llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.h
index 893b3f5415f8c7..bc3d9daef87c5f 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPUCombinerHelper.h
@@ -32,17 +32,17 @@ class AMDGPUCombinerHelper : public CombinerHelper {
                        MachineDominatorTree *MDT, const LegalizerInfo *LI,
                        const GCNSubtarget &STI);
 
-  bool matchFoldableFneg(MachineInstr &MI, MachineInstr *&MatchInfo);
-  void applyFoldableFneg(MachineInstr &MI, MachineInstr *&MatchInfo);
+  bool matchFoldableFneg(MachineInstr &MI, MachineInstr *&MatchInfo) const;
+  void applyFoldableFneg(MachineInstr &MI, MachineInstr *&MatchInfo) const;
 
   bool matchExpandPromotedF16FMed3(MachineInstr &MI, Register Src0,
-                                   Register Src1, Register Src2);
+                                   Register Src1, Register Src2) const;
   void applyExpandPromotedF16FMed3(MachineInstr &MI, Register Src0,
-                                   Register Src1, Register Src2);
+                                   Register Src1, Register Src2) const;
 
   bool matchCombineFmulWithSelectToFldexp(
       MachineInstr &MI, MachineInstr &Sel,
-      std::function<void(MachineIRBuilder &)> &MatchInfo);
+      std::function<void(MachineIRBuilder &)> &MatchInfo) const;
 };
 
 } // namespace llvm

[paulhuggett]

Thanks @arsenm. I pushed an extra commit after you approved merge to actually eliminate the "TODO" that was my goal! Hope that's okay…

I don’t have commit access; if you're happy, can you merge this PR for me (or invite any extra reviewers)?