[AMDGPU] Calculate RegWidth in bits in AsmParser

[Joe_Nash]

Summary

NFC. Switch from calculations based on dwords to bits, to be more
flexible.

[rampitec]

LGTM

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

2261–2280

I like it more condensed, with return on the same line as case, but this is a matter of taste I guess.

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

 #include "llvm/MC/MCParser/MCParsedAsmOperand.h"
 #include "llvm/MC/MCParser/MCTargetAsmParser.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Support/AMDGPUMetadata.h"
 #include "llvm/Support/AMDHSAKernelDescriptor.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/MachineValueType.h"
+#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/TargetParser.h"
 
 using namespace llvm;
 using namespace llvm::AMDGPU;
 using namespace llvm::amdhsa;
 
 namespace {
 
void initialize(MCContext &Context) {
 
     usesSgprAt(SgprIndexUnusedMin = -1);
     usesVgprAt(VgprIndexUnusedMin = -1);
     if (hasMAIInsts(*MSTI)) {
       usesAgprAt(AgprIndexUnusedMin = -1);
     }
   }
 
-  void usesRegister(RegisterKind RegKind, unsigned DwordRegIndex, unsigned RegWidth) {
+  void usesRegister(RegisterKind RegKind, unsigned DwordRegIndex,
+                    unsigned RegWidth) {
     switch (RegKind) {
-      case IS_SGPR: usesSgprAt(DwordRegIndex + RegWidth - 1); break;
-      case IS_AGPR: usesAgprAt(DwordRegIndex + RegWidth - 1); break;
-      case IS_VGPR: usesVgprAt(DwordRegIndex + RegWidth - 1); break;
-      default: break;
+    case IS_SGPR:
+      usesSgprAt(DwordRegIndex + divideCeil(RegWidth, 32) - 1);
+      break;
+    case IS_AGPR:
+      usesAgprAt(DwordRegIndex + divideCeil(RegWidth, 32) - 1);
+      break;
+    case IS_VGPR:
+      usesVgprAt(DwordRegIndex + divideCeil(RegWidth, 32) - 1);
+      break;
+    default:
+      break;
     }
   }
 };
 
 class AMDGPUAsmParser : public MCTargetAsmParser {
   MCAsmParser &Parser;
 
   // Number of extra operands parsed after the first optional operand.

 //===----------------------------------------------------------------------===//
 // AsmParser
 //===----------------------------------------------------------------------===//
 
 static int getRegClass(RegisterKind Is, unsigned RegWidth) {
   if (Is == IS_VGPR) {
     switch (RegWidth) {
       default: return -1;
-      case 1: return AMDGPU::VGPR_32RegClassID;
-      case 2: return AMDGPU::VReg_64RegClassID;
-      case 3: return AMDGPU::VReg_96RegClassID;
-      case 4: return AMDGPU::VReg_128RegClassID;
-      case 5: return AMDGPU::VReg_160RegClassID;
-      case 6: return AMDGPU::VReg_192RegClassID;
-      case 7: return AMDGPU::VReg_224RegClassID;
-      case 8: return AMDGPU::VReg_256RegClassID;
-      case 16: return AMDGPU::VReg_512RegClassID;
-      case 32: return AMDGPU::VReg_1024RegClassID;
+      case 32:
+        return AMDGPU::VGPR_32RegClassID;
+      case 64:
+        return AMDGPU::VReg_64RegClassID;
+      case 96:
+        return AMDGPU::VReg_96RegClassID;
+      case 128:
+        return AMDGPU::VReg_128RegClassID;
+      case 160:
+        return AMDGPU::VReg_160RegClassID;
+      case 192:
+        return AMDGPU::VReg_192RegClassID;
+      case 224:
+        return AMDGPU::VReg_224RegClassID;
+      case 256:
+        return AMDGPU::VReg_256RegClassID;
+      case 512:
+        return AMDGPU::VReg_512RegClassID;
+      case 1024:
+        return AMDGPU::VReg_1024RegClassID;
     }
   } else if (Is == IS_TTMP) {
     switch (RegWidth) {
       default: return -1;
-      case 1: return AMDGPU::TTMP_32RegClassID;
-      case 2: return AMDGPU::TTMP_64RegClassID;
-      case 4: return AMDGPU::TTMP_128RegClassID;
-      case 8: return AMDGPU::TTMP_256RegClassID;
-      case 16: return AMDGPU::TTMP_512RegClassID;
+      case 32:
+        return AMDGPU::TTMP_32RegClassID;
+      case 64:
+        return AMDGPU::TTMP_64RegClassID;
+      case 128:
+        return AMDGPU::TTMP_128RegClassID;
+      case 256:
+        return AMDGPU::TTMP_256RegClassID;
+      case 512:
+        return AMDGPU::TTMP_512RegClassID;
     }
   } else if (Is == IS_SGPR) {
     switch (RegWidth) {
       default: return -1;
-      case 1: return AMDGPU::SGPR_32RegClassID;
-      case 2: return AMDGPU::SGPR_64RegClassID;
-      case 3: return AMDGPU::SGPR_96RegClassID;
-      case 4: return AMDGPU::SGPR_128RegClassID;
-      case 5: return AMDGPU::SGPR_160RegClassID;
-      case 6: return AMDGPU::SGPR_192RegClassID;
-      case 7: return AMDGPU::SGPR_224RegClassID;
-      case 8: return AMDGPU::SGPR_256RegClassID;
-      case 16: return AMDGPU::SGPR_512RegClassID;
+      case 32:
+        return AMDGPU::SGPR_32RegClassID;
+      case 64:
+        return AMDGPU::SGPR_64RegClassID;
+      case 96:
+        return AMDGPU::SGPR_96RegClassID;
+      case 128:
+        return AMDGPU::SGPR_128RegClassID;
+      case 160:
+        return AMDGPU::SGPR_160RegClassID;
+      case 192:
+        return AMDGPU::SGPR_192RegClassID;
+      case 224:
+        return AMDGPU::SGPR_224RegClassID;
+      case 256:
+        return AMDGPU::SGPR_256RegClassID;
+      case 512:
+        return AMDGPU::SGPR_512RegClassID;
     }
   } else if (Is == IS_AGPR) {
     switch (RegWidth) {
       default: return -1;
-      case 1: return AMDGPU::AGPR_32RegClassID;
-      case 2: return AMDGPU::AReg_64RegClassID;
-      case 3: return AMDGPU::AReg_96RegClassID;
-      case 4: return AMDGPU::AReg_128RegClassID;
-      case 5: return AMDGPU::AReg_160RegClassID;
-      case 6: return AMDGPU::AReg_192RegClassID;
-      case 7: return AMDGPU::AReg_224RegClassID;
-      case 8: return AMDGPU::AReg_256RegClassID;
-      case 16: return AMDGPU::AReg_512RegClassID;
-      case 32: return AMDGPU::AReg_1024RegClassID;
+      case 32:
+        return AMDGPU::AGPR_32RegClassID;
+      case 64:
+        return AMDGPU::AReg_64RegClassID;
+      case 96:
+        return AMDGPU::AReg_96RegClassID;
+      case 128:
+        return AMDGPU::AReg_128RegClassID;
+      case 160:
+        return AMDGPU::AReg_160RegClassID;
+      case 192:
+        return AMDGPU::AReg_192RegClassID;
+      case 224:
+        return AMDGPU::AReg_224RegClassID;
+      case 256:
+        return AMDGPU::AReg_256RegClassID;
+      case 512:
+        return AMDGPU::AReg_512RegClassID;
+      case 1024:
+        return AMDGPU::AReg_1024RegClassID;
     }
   }
   return -1;
 }
 
 static unsigned getSpecialRegForName(StringRef RegName) {
   return StringSwitch<unsigned>(RegName)
     .Case("exec", AMDGPU::EXEC)

 
 bool AMDGPUAsmParser::AddNextRegisterToList(unsigned &Reg, unsigned &RegWidth,
                                             RegisterKind RegKind, unsigned Reg1,
                                             SMLoc Loc) {
   switch (RegKind) {
   case IS_SPECIAL:
     if (Reg == AMDGPU::EXEC_LO && Reg1 == AMDGPU::EXEC_HI) {
       Reg = AMDGPU::EXEC;
-      RegWidth = 2;
+      RegWidth = 64;
       return true;
     }
     if (Reg == AMDGPU::FLAT_SCR_LO && Reg1 == AMDGPU::FLAT_SCR_HI) {
       Reg = AMDGPU::FLAT_SCR;
-      RegWidth = 2;
+      RegWidth = 64;
       return true;
     }
     if (Reg == AMDGPU::XNACK_MASK_LO && Reg1 == AMDGPU::XNACK_MASK_HI) {
       Reg = AMDGPU::XNACK_MASK;
-      RegWidth = 2;
+      RegWidth = 64;
       return true;
     }
     if (Reg == AMDGPU::VCC_LO && Reg1 == AMDGPU::VCC_HI) {
       Reg = AMDGPU::VCC;
-      RegWidth = 2;
+      RegWidth = 64;
       return true;
     }
     if (Reg == AMDGPU::TBA_LO && Reg1 == AMDGPU::TBA_HI) {
       Reg = AMDGPU::TBA;
-      RegWidth = 2;
+      RegWidth = 64;
       return true;
     }
     if (Reg == AMDGPU::TMA_LO && Reg1 == AMDGPU::TMA_HI) {
       Reg = AMDGPU::TMA;
-      RegWidth = 2;
+      RegWidth = 64;
       return true;
     }
     Error(Loc, "register does not fit in the list");
     return false;
   case IS_VGPR:
   case IS_SGPR:
   case IS_AGPR:
   case IS_TTMP:
-    if (Reg1 != Reg + RegWidth) {
+    if (Reg1 != Reg + RegWidth / 32) {
       Error(Loc, "registers in a list must have consecutive indices");
       return false;
     }
-    RegWidth++;
+    RegWidth += 32;
     return true;
   default:
     llvm_unreachable("unexpected register kind");
   }
 }
 
 struct RegInfo {
   StringLiteral Name;
AMDGPUAsmParser::getRegularReg(RegisterKind RegKind,
                                SMLoc Loc) {
 
   assert(isRegularReg(RegKind));
 
   unsigned AlignSize = 1;
   if (RegKind == IS_SGPR || RegKind == IS_TTMP) {
     // SGPR and TTMP registers must be aligned.
     // Max required alignment is 4 dwords.
-    AlignSize = std::min(RegWidth, 4u);
+    AlignSize = std::min(RegWidth / 32, 4u);
   }
 
   if (RegNum % AlignSize != 0) {
     Error(Loc, "invalid register alignment");
     return AMDGPU::NoRegister;
   }
 
   unsigned RegIdx = RegNum / AlignSize;
   int RCID = getRegClass(RegKind, RegWidth);
   if (RCID == -1) {
     Error(Loc, "invalid or unsupported register size");
     return AMDGPU::NoRegister;
   }
 
   const MCRegisterInfo *TRI = getContext().getRegisterInfo();
   const MCRegisterClass RC = TRI->getRegClass(RCID);
   if (RegIdx >= RC.getNumRegs()) {
     Error(Loc, "register index is out of range");
     return AMDGPU::NoRegister;
   }
 
   return RC.getRegister(RegIdx);
 }
 
-bool
-AMDGPUAsmParser::ParseRegRange(unsigned& Num, unsigned& Width) {
+bool AMDGPUAsmParser::ParseRegRange(unsigned &Num, unsigned &RegWidth) {
   int64_t RegLo, RegHi;
   if (!skipToken(AsmToken::LBrac, "missing register index"))
     return false;
 
   SMLoc FirstIdxLoc = getLoc();
   SMLoc SecondIdxLoc;
 
   if (!parseExpr(RegLo))
bool AMDGPUAsmParser::ParseRegRange(unsigned &Num, unsigned &RegWidth) {
   }
 
   if (RegLo > RegHi) {
     Error(FirstIdxLoc, "first register index should not exceed second index");
     return false;
   }
 
   Num = static_cast<unsigned>(RegLo);
-  Width = (RegHi - RegLo) + 1;
+  RegWidth = 32 * ((RegHi - RegLo) + 1);
   return true;
 }
 
 unsigned AMDGPUAsmParser::ParseSpecialReg(RegisterKind &RegKind,
                                           unsigned &RegNum, unsigned &RegWidth,
                                           SmallVectorImpl<AsmToken> &Tokens) {
   assert(isToken(AsmToken::Identifier));
   unsigned Reg = getSpecialRegForName(getTokenStr());
   if (Reg) {
     RegNum = 0;
-    RegWidth = 1;
+    RegWidth = 32;
     RegKind = IS_SPECIAL;
     Tokens.push_back(getToken());
     lex(); // skip register name
   }
   return Reg;
 }
 
 unsigned AMDGPUAsmParser::ParseRegularReg(RegisterKind &RegKind,
unsigned AMDGPUAsmParser::ParseRegularReg(RegisterKind &RegKind,
   RegKind = RI->Kind;
   StringRef RegSuffix = RegName.substr(RI->Name.size());
   if (!RegSuffix.empty()) {
     // Single 32-bit register: vXX.
     if (!getRegNum(RegSuffix, RegNum)) {
       Error(Loc, "invalid register index");
       return AMDGPU::NoRegister;
     }
-    RegWidth = 1;
+    RegWidth = 32;
   } else {
     // Range of registers: v[XX:YY]. ":YY" is optional.
     if (!ParseRegRange(RegNum, RegWidth))
       return AMDGPU::NoRegister;
   }
 
   return getRegularReg(RegKind, RegNum, RegWidth, Loc);
 }
if (!skipToken(AsmToken::LBrac,
     return AMDGPU::NoRegister;
   }
 
   // List of consecutive registers, e.g.: [s0,s1,s2,s3]
 
   auto Loc = getLoc();
   if (!ParseAMDGPURegister(RegKind, Reg, RegNum, RegWidth))
     return AMDGPU::NoRegister;
-  if (RegWidth != 1) {
+  if (RegWidth != 32) {
     Error(Loc, "expected a single 32-bit register");
     return AMDGPU::NoRegister;
   }
 
   for (; trySkipToken(AsmToken::Comma); ) {
     RegisterKind NextRegKind;
     unsigned NextReg, NextRegNum, NextRegWidth;
     Loc = getLoc();
 
     if (!ParseAMDGPURegister(NextRegKind, NextReg,
                              NextRegNum, NextRegWidth,
                              Tokens)) {
       return AMDGPU::NoRegister;
     }
-    if (NextRegWidth != 1) {
+    if (NextRegWidth != 32) {
       Error(Loc, "expected a single 32-bit register");
       return AMDGPU::NoRegister;
     }
     if (NextRegKind != RegKind) {
       Error(Loc, "registers in a list must be of the same kind");
       return AMDGPU::NoRegister;
     }
     if (!AddNextRegisterToList(Reg, RegWidth, RegKind, NextReg, Loc))
bool AMDGPUAsmParser::updateGprCountSymbols(RegisterKind RegKind,
   if (AMDGPU::getIsaVersion(getSTI().getCPU()).Major < 6)
     return true;
 
   auto SymbolName = getGprCountSymbolName(RegKind);
   if (!SymbolName)
     return true;
   MCSymbol *Sym = getContext().getOrCreateSymbol(*SymbolName);
 
-  int64_t NewMax = DwordRegIndex + RegWidth - 1;
+  int64_t NewMax = DwordRegIndex + divideCeil(RegWidth, 32) - 1;
   int64_t OldCount;
 
   if (!Sym->isVariable())
     return !Error(getLoc(),
                   ".amdgcn.next_free_{v,s}gpr symbols must be variable");
   if (!Sym->getVariableValue(false)->evaluateAsAbsolute(OldCount))
     return !Error(
         getLoc(),