[llvm] SPARC: Use RegClassByHwMode instead of PointerLikeRegClass (PR #158271)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm updated https://github.com/llvm/llvm-project/pull/158271

>From 4ed75500d20460594c6fca3d4bcb3442ab2c66bd Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Mon, 8 Sep 2025 14:04:59 +0900
Subject: [PATCH] SPARC: Use RegClassByHwMode instead of PointerLikeRegClass

---
 .../Sparc/Disassembler/SparcDisassembler.cpp  |  8 -------
 llvm/lib/Target/Sparc/SparcInstrInfo.td       | 21 +++++++++++++++++--
 2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp b/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp
index c3d60f3689e1f..e585e5af42d32 100644
--- a/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp
+++ b/llvm/lib/Target/Sparc/Disassembler/SparcDisassembler.cpp
@@ -159,14 +159,6 @@ static DecodeStatus DecodeI64RegsRegisterClass(MCInst &Inst, unsigned RegNo,
   return DecodeIntRegsRegisterClass(Inst, RegNo, Address, Decoder);
 }
 
-// This is used for the type "ptr_rc", which is either IntRegs or I64Regs
-// depending on SparcRegisterInfo::getPointerRegClass.
-static DecodeStatus DecodePointerLikeRegClass0(MCInst &Inst, unsigned RegNo,
-                                               uint64_t Address,
-                                               const MCDisassembler *Decoder) {
-  return DecodeIntRegsRegisterClass(Inst, RegNo, Address, Decoder);
-}
-
 static DecodeStatus DecodeFPRegsRegisterClass(MCInst &Inst, unsigned RegNo,
                                               uint64_t Address,
                                               const MCDisassembler *Decoder) {
diff --git a/llvm/lib/Target/Sparc/SparcInstrInfo.td b/llvm/lib/Target/Sparc/SparcInstrInfo.td
index 53972d6c105a4..97e7fd7769edb 100644
--- a/llvm/lib/Target/Sparc/SparcInstrInfo.td
+++ b/llvm/lib/Target/Sparc/SparcInstrInfo.td
@@ -95,10 +95,27 @@ def HasFSMULD : Predicate<"!Subtarget->hasNoFSMULD()">;
 // will pick deprecated instructions.
 def UseDeprecatedInsts : Predicate<"Subtarget->useV8DeprecatedInsts()">;
 
+//===----------------------------------------------------------------------===//
+// HwModes Pattern Stuff
+//===----------------------------------------------------------------------===//
+
+defvar SPARC32 = DefaultMode;
+def SPARC64 : HwMode<[Is64Bit]>;
+
 //===----------------------------------------------------------------------===//
 // Instruction Pattern Stuff
 //===----------------------------------------------------------------------===//
 
+def sparc_ptr_rc : RegClassByHwMode<
+  [SPARC32, SPARC64],
+  [IntRegs, I64Regs]>;
+
+// Both cases can use the same decoder method, so avoid the dispatch
+// by hwmode by setting an explicit DecoderMethod
+def ptr_op : RegisterOperand<sparc_ptr_rc> {
+  let DecoderMethod = "DecodeIntRegsRegisterClass";
+}
+
 // FIXME these should have AsmOperandClass.
 def uimm3 : PatLeaf<(imm), [{ return isUInt<3>(N->getZExtValue()); }]>;
 
@@ -178,12 +195,12 @@ def simm13Op : Operand<iPTR> {
 
 def MEMrr : Operand<iPTR> {
   let PrintMethod = "printMemOperand";
-  let MIOperandInfo = (ops ptr_rc, ptr_rc);
+  let MIOperandInfo = (ops ptr_op, ptr_op);
   let ParserMatchClass = SparcMEMrrAsmOperand;
 }
 def MEMri : Operand<iPTR> {
   let PrintMethod = "printMemOperand";
-  let MIOperandInfo = (ops ptr_rc, simm13Op);
+  let MIOperandInfo = (ops ptr_op, simm13Op);
   let ParserMatchClass = SparcMEMriAsmOperand;
 }