Revert "[NFC] Make FPClassTest a bitmask enumeration"

This reverts commit 2e416cdd52.

Breaks the GCC build:

In file included from /home/npopov/repos/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:18,
                 from /home/npopov/repos/llvm-project/llvm/include/llvm/ADT/APFloat.h:20,
                 from /home/npopov/repos/llvm-project/llvm/lib/Support/APFloat.cpp:14:
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/BitmaskEnum.h:66:22: error: extra qualification not allowed [-fpermissive]
   66 |   template <> struct llvm::is_bitmask_enum<Enum> : std::true_type {};          \
      |                      ^~~~
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:223:1: note: in expansion of macro ‘LLVM_DECLARE_ENUM_AS_BITMASK’
  223 | LLVM_DECLARE_ENUM_AS_BITMASK(FPClassTest, /* LargestValue */ fcPosInf);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/BitmaskEnum.h:67:22: error: extra qualification not allowed [-fpermissive]
   67 |   template <> struct llvm::largest_bitmask_enum_bit<Enum> {                    \
      |                      ^~~~
/home/npopov/repos/llvm-project/llvm/include/llvm/ADT/FloatingPointMode.h:223:1: note: in expansion of macro ‘LLVM_DECLARE_ENUM_AS_BITMASK’
  223 | LLVM_DECLARE_ENUM_AS_BITMASK(FPClassTest, /* LargestValue */ fcPosInf);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
[43/4396] Building CXX object lib/Supp...iles/LLVMSupport.dir/CommandLine.cpp.o

llvm/include/llvm/ADT/FloatingPointMode.h

@@ -15,7 +15,6 @@
 #ifndef LLVM_ADT_FLOATINGPOINTMODE_H
 #define LLVM_ADT_FLOATINGPOINTMODE_H
 
-#include "llvm/ADT/BitmaskEnum.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/raw_ostream.h"
 
@@ -193,11 +192,11 @@ void DenormalMode::print(raw_ostream &OS) const {
   OS << denormalModeKindName(Output) << ',' << denormalModeKindName(Input);
 }
 
+} // namespace llvm
+
 /// Floating-point class tests, supported by 'is_fpclass' intrinsic. Actual
 /// test may be an OR combination of basic tests.
-enum FPClassTest : unsigned {
-  fcNone = 0,
-
+enum FPClassTest {
   fcSNan = 0x0001,
   fcQNan = 0x0002,
   fcNegInf = 0x0004,
@@ -217,11 +216,7 @@ enum FPClassTest : unsigned {
   fcPosFinite = fcPosNormal | fcPosSubnormal | fcPosZero,
   fcNegFinite = fcNegNormal | fcNegSubnormal | fcNegZero,
   fcFinite = fcPosFinite | fcNegFinite,
-  fcAllFlags = fcNan | fcInf | fcFinite,
+  fcAllFlags = fcNan | fcInf | fcFinite
 };
 
-LLVM_DECLARE_ENUM_AS_BITMASK(FPClassTest, /* LargestValue */ fcPosInf);
-
-} // namespace llvm
-
 #endif // LLVM_ADT_FLOATINGPOINTMODE_H

llvm/include/llvm/CodeGen/CodeGenCommonISel.h

@@ -19,8 +19,6 @@
 namespace llvm {
 
 class BasicBlock;
-enum FPClassTest : unsigned;
-
 /// Encapsulates all of the information needed to generate a stack protector
 /// check, and signals to isel when initialized that one needs to be generated.
 ///
@@ -220,7 +218,7 @@ findSplitPointForStackProtector(MachineBasicBlock *BB,
 /// \param Test The test as specified in 'is_fpclass' intrinsic invocation.
 /// \returns The inverted test, or zero, if inversion does not produce simpler
 /// test.
-FPClassTest getInvertedFPClassTest(FPClassTest Test);
+unsigned getInvertedFPClassTest(unsigned Test);
 
 /// Assuming the instruction \p MI is going to be deleted, attempt to salvage
 /// debug users of \p MI by writing the effect of \p MI in a DIExpression.

llvm/include/llvm/CodeGen/TargetLowering.h

@@ -4956,7 +4956,7 @@ public:
   /// \param Test The test to perform.
   /// \param Flags The optimization flags.
   /// \returns The expansion result or SDValue() if it fails.
-  SDValue expandIS_FPCLASS(EVT ResultVT, SDValue Op, FPClassTest Test,
+  SDValue expandIS_FPCLASS(EVT ResultVT, SDValue Op, unsigned Test,
                            SDNodeFlags Flags, const SDLoc &DL,
                            SelectionDAG &DAG) const;
 

llvm/lib/CodeGen/CodeGenCommonISel.cpp

@@ -173,8 +173,8 @@ llvm::findSplitPointForStackProtector(MachineBasicBlock *BB,
   return SplitPoint;
 }
 
-FPClassTest llvm::getInvertedFPClassTest(FPClassTest Test) {
-  FPClassTest InvertedTest = ~Test & fcAllFlags;
+unsigned llvm::getInvertedFPClassTest(unsigned Test) {
+  unsigned InvertedTest = ~Test & fcAllFlags;
   switch (InvertedTest) {
   default:
     break;
@@ -198,7 +198,7 @@ FPClassTest llvm::getInvertedFPClassTest(FPClassTest Test) {
   case fcNegFinite:
     return InvertedTest;
   }
-  return fcNone;
+  return 0;
 }
 
 static MachineOperand *getSalvageOpsForCopy(const MachineRegisterInfo &MRI,

llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

@@ -6510,8 +6510,7 @@ void SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I,
     const DataLayout DLayout = DAG.getDataLayout();
     EVT DestVT = TLI.getValueType(DLayout, I.getType());
     EVT ArgVT = TLI.getValueType(DLayout, I.getArgOperand(0)->getType());
-    FPClassTest Test = static_cast<FPClassTest>(
-        cast<ConstantInt>(I.getArgOperand(1))->getZExtValue());
+    unsigned Test = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue();
     MachineFunction &MF = DAG.getMachineFunction();
     const Function &F = MF.getFunction();
     SDValue Op = getValue(I.getArgOperand(0));

llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -8004,7 +8004,7 @@ SDValue TargetLowering::expandFMINNUM_FMAXNUM(SDNode *Node,
 }
 
 SDValue TargetLowering::expandIS_FPCLASS(EVT ResultVT, SDValue Op,
-                                         FPClassTest Test, SDNodeFlags Flags,
+                                         unsigned Test, SDNodeFlags Flags,
                                          const SDLoc &DL,
                                          SelectionDAG &DAG) const {
   EVT OperandVT = Op.getValueType();
@@ -8027,7 +8027,7 @@ SDValue TargetLowering::expandIS_FPCLASS(EVT ResultVT, SDValue Op,
   // Some checks may be represented as inversion of simpler check, for example
   // "inf|normal|subnormal|zero" => !"nan".
   bool IsInverted = false;
-  if (FPClassTest InvertedCheck = getInvertedFPClassTest(Test)) {
+  if (unsigned InvertedCheck = getInvertedFPClassTest(Test)) {
     IsInverted = true;
     Test = InvertedCheck;
   }

llvm/lib/IR/Verifier.cpp

@@ -5070,7 +5070,7 @@ void Verifier::visitIntrinsicCall(Intrinsic::ID ID, CallBase &Call) {
   }
   case Intrinsic::is_fpclass: {
     const ConstantInt *TestMask = cast<ConstantInt>(Call.getOperand(1));
-    Check((TestMask->getZExtValue() & ~static_cast<unsigned>(fcAllFlags)) == 0,
+    Check((TestMask->getZExtValue() & ~fcAllFlags) == 0,
           "unsupported bits for llvm.is.fpclass test mask");
     break;
   }