[ARM] Tidy-up condition-code support functions

[javed.absar]

Summary

Move condition code support functions to Utils and remove code duplication.

[fhahn]

Thanks, LGTM.

This looks like a NFC to me and removes some unnecessary code duplication.

lib/Target/ARM/Utils/ARMBaseInfo.h

51

While you are at it, would it make sense to remove the default case there and add the llvm_unreachable after the switch like in ARMCondCodeToString?

This would give the compiler a better chance to warn about missing patterns, but that's only a minor point, as it's unlikely that CondCodes will change.

[javed.absar]

lib/Target/ARM/Utils/ARMBaseInfo.h

51

Thanks. Will do so.

[javed.absar]

lib/Target/ARM/Utils/ARMBaseInfo.h

51

Looking at it again, that does not seem a good idea. There is no 'OppositCondition' for 'AL' (Always). Taking out the default will just trigger sprurious compilation warning - enumeration value 'AL' not handled in switch

lib/Target/ARM/AsmParser/ARMAsmParser.cpp

 /// parseITCondCode - Try to parse a condition code for an IT instruction.
 OperandMatchResultTy
 ARMAsmParser::parseITCondCode(OperandVector &Operands) {
   MCAsmParser &Parser = getParser();
   SMLoc S = Parser.getTok().getLoc();
   const AsmToken &Tok = Parser.getTok();
   if (!Tok.is(AsmToken::Identifier))
     return MatchOperand_NoMatch;
-  unsigned CC = StringSwitch<unsigned>(Tok.getString().lower())
-    .Case("eq", ARMCC::EQ)
-    .Case("ne", ARMCC::NE)
-    .Case("hs", ARMCC::HS)
-    .Case("cs", ARMCC::HS)
-    .Case("lo", ARMCC::LO)
-    .Case("cc", ARMCC::LO)
-    .Case("mi", ARMCC::MI)
-    .Case("pl", ARMCC::PL)
-    .Case("vs", ARMCC::VS)
-    .Case("vc", ARMCC::VC)
-    .Case("hi", ARMCC::HI)
-    .Case("ls", ARMCC::LS)
-    .Case("ge", ARMCC::GE)
-    .Case("lt", ARMCC::LT)
-    .Case("gt", ARMCC::GT)
-    .Case("le", ARMCC::LE)
-    .Case("al", ARMCC::AL)
-    .Default(~0U);
+  unsigned CC = ARMCondCodeFromString(Tok.getString());
   if (CC == ~0U)
     return MatchOperand_NoMatch;
   Parser.Lex(); // Eat the token.
 
   Operands.push_back(ARMOperand::CreateCondCode(ARMCC::CondCodes(CC), S));
 
   return MatchOperand_Success;
 }
if ((Mnemonic == "movs" && isThumb()) ||
     return Mnemonic;
 
   // First, split out any predication code. Ignore mnemonics we know aren't
   // predicated but do have a carry-set and so weren't caught above.
   if (Mnemonic != "adcs" && Mnemonic != "bics" && Mnemonic != "movs" &&
       Mnemonic != "muls" && Mnemonic != "smlals" && Mnemonic != "smulls" &&
       Mnemonic != "umlals" && Mnemonic != "umulls" && Mnemonic != "lsls" &&
       Mnemonic != "sbcs" && Mnemonic != "rscs") {
-    unsigned CC = StringSwitch<unsigned>(Mnemonic.substr(Mnemonic.size()-2))
-      .Case("eq", ARMCC::EQ)
-      .Case("ne", ARMCC::NE)
-      .Case("hs", ARMCC::HS)
-      .Case("cs", ARMCC::HS)
-      .Case("lo", ARMCC::LO)
-      .Case("cc", ARMCC::LO)
-      .Case("mi", ARMCC::MI)
-      .Case("pl", ARMCC::PL)
-      .Case("vs", ARMCC::VS)
-      .Case("vc", ARMCC::VC)
-      .Case("hi", ARMCC::HI)
-      .Case("ls", ARMCC::LS)
-      .Case("ge", ARMCC::GE)
-      .Case("lt", ARMCC::LT)
-      .Case("gt", ARMCC::GT)
-      .Case("le", ARMCC::LE)
-      .Case("al", ARMCC::AL)
-      .Default(~0U);
+    unsigned CC = ARMCondCodeFromString(Mnemonic.substr(Mnemonic.size()-2));
     if (CC != ~0U) {
       Mnemonic = Mnemonic.slice(0, Mnemonic.size() - 2);
       PredicationCode = CC;
     }
   }
 
   // Next, determine if we have a carry setting bit. We explicitly ignore all
   // the instructions we know end in 's'.

lib/Target/ARM/MCTargetDesc/ARMBaseInfo.h

 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_TARGET_ARM_MCTARGETDESC_ARMBASEINFO_H
 #define LLVM_LIB_TARGET_ARM_MCTARGETDESC_ARMBASEINFO_H
 
 #include "ARMMCTargetDesc.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "Utils/ARMBaseInfo.h"
 
 namespace llvm {
 
-// Enums corresponding to ARM condition codes
-namespace ARMCC {
-  // The CondCodes constants map directly to the 4-bit encoding of the
-  // condition field for predicated instructions.
-  enum CondCodes { // Meaning (integer)          Meaning (floating-point)
-    EQ,            // Equal                      Equal
-    NE,            // Not equal                  Not equal, or unordered
-    HS,            // Carry set                  >, ==, or unordered
-    LO,            // Carry clear                Less than
-    MI,            // Minus, negative            Less than
-    PL,            // Plus, positive or zero     >, ==, or unordered
-    VS,            // Overflow                   Unordered
-    VC,            // No overflow                Not unordered
-    HI,            // Unsigned higher            Greater than, or unordered
-    LS,            // Unsigned lower or same     Less than or equal
-    GE,            // Greater than or equal      Greater than or equal
-    LT,            // Less than                  Less than, or unordered
-    GT,            // Greater than               Greater than
-    LE,            // Less than or equal         <, ==, or unordered
-    AL             // Always (unconditional)     Always (unconditional)
-  };
-
-  inline static CondCodes getOppositeCondition(CondCodes CC) {
-    switch (CC) {
-    default: llvm_unreachable("Unknown condition code");
-    case EQ: return NE;
-    case NE: return EQ;
-    case HS: return LO;
-    case LO: return HS;
-    case MI: return PL;
-    case PL: return MI;
-    case VS: return VC;
-    case VC: return VS;
-    case HI: return LS;
-    case LS: return HI;
-    case GE: return LT;
-    case LT: return GE;
-    case GT: return LE;
-    case LE: return GT;
-    }
-  }
-} // namespace ARMCC
-
-inline static const char *ARMCondCodeToString(ARMCC::CondCodes CC) {
-  switch (CC) {
-  case ARMCC::EQ:  return "eq";
-  case ARMCC::NE:  return "ne";
-  case ARMCC::HS:  return "hs";
-  case ARMCC::LO:  return "lo";
-  case ARMCC::MI:  return "mi";
-  case ARMCC::PL:  return "pl";
-  case ARMCC::VS:  return "vs";
-  case ARMCC::VC:  return "vc";
-  case ARMCC::HI:  return "hi";
-  case ARMCC::LS:  return "ls";
-  case ARMCC::GE:  return "ge";
-  case ARMCC::LT:  return "lt";
-  case ARMCC::GT:  return "gt";
-  case ARMCC::LE:  return "le";
-  case ARMCC::AL:  return "al";
-  }
-  llvm_unreachable("Unknown condition code");
-}
-
 namespace ARM_PROC {
   enum IMod {
     IE = 2,
     ID = 3
   };
 
   enum IFlags {
     F = 1,

lib/Target/ARM/Utils/ARMBaseInfo.h

 
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/MC/SubtargetFeature.h"
 #include "MCTargetDesc/ARMMCTargetDesc.h"
 
 namespace llvm {
 
+// Enums corresponding to ARM condition codes
+namespace ARMCC {
+// The CondCodes constants map directly to the 4-bit encoding of the
+// condition field for predicated instructions.
+enum CondCodes { // Meaning (integer)          Meaning (floating-point)
+  EQ,            // Equal                      Equal
+  NE,            // Not equal                  Not equal, or unordered
+  HS,            // Carry set                  >, ==, or unordered
+  LO,            // Carry clear                Less than
+  MI,            // Minus, negative            Less than
+  PL,            // Plus, positive or zero     >, ==, or unordered
+  VS,            // Overflow                   Unordered
+  VC,            // No overflow                Not unordered
+  HI,            // Unsigned higher            Greater than, or unordered
+  LS,            // Unsigned lower or same     Less than or equal
+  GE,            // Greater than or equal      Greater than or equal
+  LT,            // Less than                  Less than, or unordered
+  GT,            // Greater than               Greater than
+  LE,            // Less than or equal         <, ==, or unordered
+  AL             // Always (unconditional)     Always (unconditional)
+};
+
+inline static CondCodes getOppositeCondition(CondCodes CC) {
+  switch (CC) {
+  default: llvm_unreachable("Unknown condition code");
+  case EQ: return NE;
+  case NE: return EQ;
+  case HS: return LO;
+  case LO: return HS;
+  case MI: return PL;
+  case PL: return MI;
+  case VS: return VC;
+  case VC: return VS;
+  case HI: return LS;
+  case LS: return HI;
+  case GE: return LT;
+  case LT: return GE;
+  case GT: return LE;
+  case LE: return GT;
+  }
+}
+} // end namespace ARMCC
+
+inline static const char *ARMCondCodeToString(ARMCC::CondCodes CC) {
+  switch (CC) {
+  case ARMCC::EQ:  return "eq";
+  case ARMCC::NE:  return "ne";
+  case ARMCC::HS:  return "hs";
+  case ARMCC::LO:  return "lo";
+  case ARMCC::MI:  return "mi";
+  case ARMCC::PL:  return "pl";
+  case ARMCC::VS:  return "vs";
+  case ARMCC::VC:  return "vc";
+  case ARMCC::HI:  return "hi";
+  case ARMCC::LS:  return "ls";
+  case ARMCC::GE:  return "ge";
+  case ARMCC::LT:  return "lt";
+  case ARMCC::GT:  return "gt";
+  case ARMCC::LE:  return "le";
+  case ARMCC::AL:  return "al";
+  }
+  llvm_unreachable("Unknown condition code");
+}
+
+inline static unsigned ARMCondCodeFromString(StringRef CC) {
+  return StringSwitch<unsigned>(CC.lower())
+    .Case("eq", ARMCC::EQ)
+    .Case("ne", ARMCC::NE)
+    .Case("hs", ARMCC::HS)
+    .Case("cs", ARMCC::HS)
+    .Case("lo", ARMCC::LO)
+    .Case("cc", ARMCC::LO)
+    .Case("mi", ARMCC::MI)
+    .Case("pl", ARMCC::PL)
+    .Case("vs", ARMCC::VS)
+    .Case("vc", ARMCC::VC)
+    .Case("hi", ARMCC::HI)
+    .Case("ls", ARMCC::LS)
+    .Case("ge", ARMCC::GE)
+    .Case("lt", ARMCC::LT)
+    .Case("gt", ARMCC::GT)
+    .Case("le", ARMCC::LE)
+    .Case("al", ARMCC::AL)
+    .Default(~0U);
+}
+
 // System Registers
 namespace ARMSysReg {
   struct MClassSysReg {
     const char *Name;
     uint16_t M1Encoding12;
     uint16_t M2M3Encoding8;
     uint16_t Encoding;
     FeatureBitset FeaturesRequired;