[AMDGPU][NFC] Rename isHi() to isHi16Reg() for clarity. (#103888)

And declare it to take an MCRegister.

Also rename related entities and remove a comment for the function that
depending on its purpose is either irrelevant or misleading.

Author: kosarev

llvm/lib/Target/AMDGPU/AsmParser/AMDGPUAsmParser.cpp

@@ -8546,7 +8546,7 @@ static void cvtVOP3DstOpSelOnly(MCInst &Inst, const MCRegisterInfo &MRI) {
   uint32_t ModVal = Inst.getOperand(ModIdx).getImm();
   if (DstOp.isReg() &&
       MRI.getRegClass(AMDGPU::VGPR_16RegClassID).contains(DstOp.getReg())) {
-    if (AMDGPU::isHi(DstOp.getReg(), MRI))
+    if (AMDGPU::isHi16Reg(DstOp.getReg(), MRI))
       ModVal |= SISrcMods::DST_OP_SEL;
   } else {
     if ((OpSel & (1 << SrcNum)) != 0)
@@ -8826,7 +8826,7 @@ void AMDGPUAsmParser::cvtVOP3P(MCInst &Inst, const OperandVector &Operands,
     if (SrcOp.isReg() && getMRI()
                              ->getRegClass(AMDGPU::VGPR_16RegClassID)
                              .contains(SrcOp.getReg())) {
-      bool VGPRSuffixIsHi = AMDGPU::isHi(SrcOp.getReg(), *getMRI());
+      bool VGPRSuffixIsHi = AMDGPU::isHi16Reg(SrcOp.getReg(), *getMRI());
       if (VGPRSuffixIsHi)
         ModVal |= SISrcMods::OP_SEL_0;
     } else {

llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCCodeEmitter.cpp

@@ -608,7 +608,7 @@ void AMDGPUMCCodeEmitter::getMachineOpValueT16(
         AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::vdst);
     if (VDstMOIdx != -1) {
       auto DstReg = MI.getOperand(VDstMOIdx).getReg();
-      if (AMDGPU::isHi(DstReg, MRI))
+      if (AMDGPU::isHi16Reg(DstReg, MRI))
         Op |= SISrcMods::DST_OP_SEL;
     }
   } else if ((int)OpNo == AMDGPU::getNamedOperandIdx(
@@ -626,7 +626,7 @@ void AMDGPUMCCodeEmitter::getMachineOpValueT16(
   auto SrcReg = SrcMO.getReg();
   if (AMDGPU::isSGPR(SrcReg, &MRI))
     return;
-  if (AMDGPU::isHi(SrcReg, MRI))
+  if (AMDGPU::isHi16Reg(SrcReg, MRI))
     Op |= SISrcMods::OP_SEL_0;
 }
 
@@ -637,7 +637,7 @@ void AMDGPUMCCodeEmitter::getMachineOpValueT16Lo128(
   if (MO.isReg()) {
     uint16_t Encoding = MRI.getEncodingValue(MO.getReg());
     unsigned RegIdx = Encoding & AMDGPU::HWEncoding::REG_IDX_MASK;
-    bool IsHi = Encoding & AMDGPU::HWEncoding::IS_HI;
+    bool IsHi = Encoding & AMDGPU::HWEncoding::IS_HI16;
     bool IsVGPR = Encoding & AMDGPU::HWEncoding::IS_VGPR;
     assert((!IsVGPR || isUInt<7>(RegIdx)) && "VGPR0-VGPR127 expected!");
     Op = (IsVGPR ? 0x100 : 0) | (IsHi ? 0x80 : 0) | RegIdx;

llvm/lib/Target/AMDGPU/SIDefines.h

@@ -371,7 +371,7 @@ enum : unsigned {
   REG_IDX_MASK = 0xff,
   IS_VGPR = 1 << 8,
   IS_AGPR = 1 << 9,
-  IS_HI = 1 << 10, // High 16-bit register.
+  IS_HI16 = 1 << 10,
 };
 } // namespace HWEncoding
 

llvm/lib/Target/AMDGPU/SIInstrInfo.cpp

@@ -954,8 +954,8 @@ void SIInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
     bool IsSGPRSrc = AMDGPU::SReg_LO16RegClass.contains(SrcReg);
     bool IsAGPRDst = AMDGPU::AGPR_LO16RegClass.contains(DestReg);
     bool IsAGPRSrc = AMDGPU::AGPR_LO16RegClass.contains(SrcReg);
-    bool DstLow = !AMDGPU::isHi(DestReg, RI);
-    bool SrcLow = !AMDGPU::isHi(SrcReg, RI);
+    bool DstLow = !AMDGPU::isHi16Reg(DestReg, RI);
+    bool SrcLow = !AMDGPU::isHi16Reg(SrcReg, RI);
     MCRegister NewDestReg = RI.get32BitRegister(DestReg);
     MCRegister NewSrcReg = RI.get32BitRegister(SrcReg);
 

llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp

@@ -332,7 +332,7 @@ SIRegisterInfo::SIRegisterInfo(const GCNSubtarget &ST)
   RegPressureIgnoredUnits.resize(getNumRegUnits());
   RegPressureIgnoredUnits.set(*regunits(MCRegister::from(AMDGPU::M0)).begin());
   for (auto Reg : AMDGPU::VGPR_16RegClass) {
-    if (AMDGPU::isHi(Reg, *this))
+    if (AMDGPU::isHi16Reg(Reg, *this))
       RegPressureIgnoredUnits.set(*regunits(Reg).begin());
   }
 

llvm/lib/Target/AMDGPU/SIRegisterInfo.td

@@ -123,7 +123,7 @@ class SIRegisterTuples<list<SubRegIndex> Indices, RegisterClass RC,
 //  Declarations that describe the SI registers
 //===----------------------------------------------------------------------===//
 class SIReg <string n, bits<8> regIdx = 0, bit isVGPR = 0,
-             bit isAGPR = 0, bit isHi = 0> : Register<n> {
+             bit isAGPR = 0, bit isHi16 = 0> : Register<n> {
   let Namespace = "AMDGPU";
 
   // These are generic helper values we use to form actual register
@@ -132,7 +132,7 @@ class SIReg <string n, bits<8> regIdx = 0, bit isVGPR = 0,
   let HWEncoding{7-0} = regIdx;
   let HWEncoding{8} = isVGPR;
   let HWEncoding{9} = isAGPR;
-  let HWEncoding{10} = isHi;
+  let HWEncoding{10} = isHi16;
 
   int Index = !cast<int>(regIdx);
 }
@@ -161,7 +161,7 @@ multiclass SIRegLoHi16 <string n, bits<8> regIdx, bit ArtificialHigh = 1,
                         bit isVGPR = 0, bit isAGPR = 0> {
   def _LO16 : SIReg<n#".l", regIdx, isVGPR, isAGPR>;
   def _HI16 : SIReg<!if(ArtificialHigh, "", n#".h"), regIdx, isVGPR, isAGPR,
-                    /* isHi */ 1> {
+                    /* isHi16 */ 1> {
     let isArtificial = ArtificialHigh;
   }
   def "" : RegisterWithSubRegs<n, [!cast<Register>(NAME#"_LO16"),

llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp

@@ -2237,8 +2237,8 @@ bool isSGPR(unsigned Reg, const MCRegisterInfo* TRI) {
     Reg == AMDGPU::SCC;
 }
 
-bool isHi(unsigned Reg, const MCRegisterInfo &MRI) {
-  return MRI.getEncodingValue(Reg) & AMDGPU::HWEncoding::IS_HI;
+bool isHi16Reg(MCRegister Reg, const MCRegisterInfo &MRI) {
+  return MRI.getEncodingValue(Reg) & AMDGPU::HWEncoding::IS_HI16;
 }
 
 #define MAP_REG2REG \

llvm/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h

@@ -1314,8 +1314,7 @@ bool hasSMRDSignedImmOffset(const MCSubtargetInfo &ST);
 bool isSGPR(unsigned Reg, const MCRegisterInfo* TRI);
 
 /// \returns if \p Reg occupies the high 16-bits of a 32-bit register.
-/// The bit indicating isHi is the LSB of the encoding.
-bool isHi(unsigned Reg, const MCRegisterInfo &MRI);
+bool isHi16Reg(MCRegister Reg, const MCRegisterInfo &MRI);
 
 /// If \p Reg is a pseudo reg, return the correct hardware register given
 /// \p STI otherwise return \p Reg.