Use std::bitset for SubtargetFeatures.

Previously, subtarget features were a bitfield with the underlying type being uint64_t. 
Since several targets (X86 and ARM, in particular) have hit or were very close to hitting this bound, switching the features to use a bitset.
No functional change.

The first several times this was committed (e.g. r229831, r233055), it caused several buildbot failures.
Apparently the reason for most failures was both clang and gcc's inability to deal with large numbers (> 10K) of bitset constructor calls in tablegen-generated initializers of instruction info tables. 
This should now be fixed.

llvm-svn: 238192

5 files changed, 31 insertions, 31 deletions

diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmInstrumentation.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmInstrumentation.cpp
index 6a206bb76f4..a21f8c72350 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmInstrumentation.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmInstrumentation.cpp
@@ -261,13 +261,13 @@ protected:
                                               MCContext &Ctx, int64_t *Residue);
 
   bool is64BitMode() const {
-    return (STI.getFeatureBits() & X86::Mode64Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode64Bit];
   }
   bool is32BitMode() const {
-    return (STI.getFeatureBits() & X86::Mode32Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode32Bit];
   }
   bool is16BitMode() const {
-    return (STI.getFeatureBits() & X86::Mode16Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode16Bit];
   }
 
   unsigned getPointerWidth() {
@@ -1072,9 +1072,9 @@ CreateX86AsmInstrumentation(const MCTargetOptions &MCOptions,
   const bool hasCompilerRTSupport = T.isOSLinux();
   if (ClAsanInstrumentAssembly && hasCompilerRTSupport &&
       MCOptions.SanitizeAddress) {
-    if ((STI.getFeatureBits() & X86::Mode32Bit) != 0)
+    if (STI.getFeatureBits()[X86::Mode32Bit] != 0)
       return new X86AddressSanitizer32(STI);
-    if ((STI.getFeatureBits() & X86::Mode64Bit) != 0)
+    if (STI.getFeatureBits()[X86::Mode64Bit] != 0)
       return new X86AddressSanitizer64(STI);
   }
   return new X86AsmInstrumentation(STI);
diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
index 6c384ffc60d..3047fd1078a 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -729,23 +729,24 @@ private:
 
   bool is64BitMode() const {
     // FIXME: Can tablegen auto-generate this?
-    return (STI.getFeatureBits() & X86::Mode64Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode64Bit];
   }
   bool is32BitMode() const {
     // FIXME: Can tablegen auto-generate this?
-    return (STI.getFeatureBits() & X86::Mode32Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode32Bit];
   }
   bool is16BitMode() const {
     // FIXME: Can tablegen auto-generate this?
-    return (STI.getFeatureBits() & X86::Mode16Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode16Bit];
   }
-  void SwitchMode(uint64_t mode) {
-    uint64_t oldMode = STI.getFeatureBits() &
-        (X86::Mode64Bit | X86::Mode32Bit | X86::Mode16Bit);
-    unsigned FB = ComputeAvailableFeatures(STI.ToggleFeature(oldMode | mode));
+  void SwitchMode(unsigned mode) {
+    FeatureBitset AllModes({X86::Mode64Bit, X86::Mode32Bit, X86::Mode16Bit});
+    FeatureBitset OldMode = STI.getFeatureBits() & AllModes;
+    unsigned FB = ComputeAvailableFeatures(
+      STI.ToggleFeature(OldMode.flip(mode)));
     setAvailableFeatures(FB);
-    assert(mode == (STI.getFeatureBits() &
-                    (X86::Mode64Bit | X86::Mode32Bit | X86::Mode16Bit)));
+    
+    assert(FeatureBitset({mode}) == (STI.getFeatureBits() & AllModes));
   }
 
   unsigned getPointerWidth() {
@@ -1696,7 +1697,7 @@ std::unique_ptr<X86Operand> X86AsmParser::ParseIntelOperand() {
   }
 
   // rounding mode token
-  if (STI.getFeatureBits() & X86::FeatureAVX512 &&
+  if (STI.getFeatureBits()[X86::FeatureAVX512] &&
       getLexer().is(AsmToken::LCurly))
     return ParseRoundingModeOp(Start, End);
 
@@ -1754,7 +1755,7 @@ std::unique_ptr<X86Operand> X86AsmParser::ParseATTOperand() {
   }
   case AsmToken::LCurly:{
     SMLoc Start = Parser.getTok().getLoc(), End;
-    if (STI.getFeatureBits() & X86::FeatureAVX512)
+    if (STI.getFeatureBits()[X86::FeatureAVX512])
       return ParseRoundingModeOp(Start, End);
     return ErrorOperand(Start, "unknown token in expression");
   }
@@ -1764,7 +1765,7 @@ std::unique_ptr<X86Operand> X86AsmParser::ParseATTOperand() {
 bool X86AsmParser::HandleAVX512Operand(OperandVector &Operands,
                                        const MCParsedAsmOperand &Op) {
   MCAsmParser &Parser = getParser();
-  if(STI.getFeatureBits() & X86::FeatureAVX512) {
+  if(STI.getFeatureBits()[X86::FeatureAVX512]) {
     if (getLexer().is(AsmToken::LCurly)) {
       // Eat "{" and mark the current place.
       const SMLoc consumedToken = consumeToken();
diff --git a/llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp b/llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp
index 772294cc360..3469d19f4fd 100644
--- a/llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp
+++ b/llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp
@@ -80,20 +80,19 @@ X86GenericDisassembler::X86GenericDisassembler(
                                          MCContext &Ctx,
                                          std::unique_ptr<const MCInstrInfo> MII)
   : MCDisassembler(STI, Ctx), MII(std::move(MII)) {
-  switch (STI.getFeatureBits() &
-          (X86::Mode16Bit | X86::Mode32Bit | X86::Mode64Bit)) {
-  case X86::Mode16Bit:
+  const FeatureBitset &FB = STI.getFeatureBits();
+  if (FB[X86::Mode16Bit]) {
     fMode = MODE_16BIT;
-    break;
-  case X86::Mode32Bit:
+    return;
+  } else if (FB[X86::Mode32Bit]) {
     fMode = MODE_32BIT;
-    break;
-  case X86::Mode64Bit:
+    return;
+  } else if (FB[X86::Mode64Bit]) {
     fMode = MODE_64BIT;
-    break;
-  default:
-    llvm_unreachable("Invalid CPU mode");
+    return;
   }
+
+  llvm_unreachable("Invalid CPU mode");
 }
 
 struct Region {
diff --git a/llvm/lib/Target/X86/InstPrinter/X86ATTInstPrinter.cpp b/llvm/lib/Target/X86/InstPrinter/X86ATTInstPrinter.cpp
index f265f1dee9d..e0b6c50415b 100644
--- a/llvm/lib/Target/X86/InstPrinter/X86ATTInstPrinter.cpp
+++ b/llvm/lib/Target/X86/InstPrinter/X86ATTInstPrinter.cpp
@@ -57,7 +57,7 @@ void X86ATTInstPrinter::printInst(const MCInst *MI, raw_ostream &OS,
   // InstrInfo.td as soon as Requires clause is supported properly
   // for InstAlias.
   if (MI->getOpcode() == X86::CALLpcrel32 &&
-      (STI.getFeatureBits() & X86::Mode64Bit) != 0) {
+      (STI.getFeatureBits()[X86::Mode64Bit])) {
     OS << "\tcallq\t";
     printPCRelImm(MI, 0, OS);
   }
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
index 3affef0a50c..8aed7a4d9eb 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
@@ -42,15 +42,15 @@ public:
   ~X86MCCodeEmitter() override {}
 
   bool is64BitMode(const MCSubtargetInfo &STI) const {
-    return (STI.getFeatureBits() & X86::Mode64Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode64Bit];
   }
 
   bool is32BitMode(const MCSubtargetInfo &STI) const {
-    return (STI.getFeatureBits() & X86::Mode32Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode32Bit];
   }
 
   bool is16BitMode(const MCSubtargetInfo &STI) const {
-    return (STI.getFeatureBits() & X86::Mode16Bit) != 0;
+    return STI.getFeatureBits()[X86::Mode16Bit];
   }
 
   /// Is16BitMemOperand - Return true if the specified instruction has