[Clang][RISCV] Restrict rvv builtins with zve macros

[eopXD]

Summary

The zve extension specifies the maximum ELEN for both integer and floating
point mode - defined by macro __riscv_v_elen and __riscv_v_elen_fp.
This commit restricts the functions in riscv_vector.h by the zve defined
macro-s.

Change enum RISCVExtension to RISCVPredefinedMacro since now it
contains not only extensions. Also added type alignment to it.

[eopXD]

Rebase.

[eopXD]

This revision is no longer needed as zvamo and zvlsseg will be removed from arch string.

[eopXD]

This was closed by my misunderstanding.
For clang we still need to do some restrictions based on ELEN.
Reopening.

[eopXD]

Update code.

[eopXD]

Update code.

[craig.topper]

clang/utils/TableGen/RISCVVEmitter.cpp

148

Do we need VectorMaxELen32 isn't that the minimum?

800–801

Can D and F go away?

[eopXD]

Rebase and addres comments.
Resolve conflcits due to zvlsseg removal.

clang/utils/TableGen/RISCVVEmitter.cpp

148

Yes you are correct. We don't need it.

800–801

Done.

[eopXD]

Follow clang-format.

[craig.topper]

clang/utils/TableGen/RISCVVEmitter.cpp

144

Drop F and D here?

1317

Drop F and D here

[eopXD]

Cleanup unused enum.

[craig.topper]

LGTM

[frasercrmck]

LGTM too. Though the commit title and message has hyphens in places I wouldn't expect them. macros and builtins is fine.

clang/utils/TableGen/RISCVVEmitter.cpp

798

nit: This still says "extensions"

[eopXD]

In D112986#3261933, @frasercrmck wrote:

LGTM too. Though the commit title and message has hyphens in places I wouldn't expect them. macros and builtins is fine.

Thank you to also drop by and take a look :)

clang/utils/TableGen/RISCVVEmitter.cpp

798

Yeah I thought of not changing the variable name, however as other enums are added in keeping it as "extensions" is a bit strange to me.

clang/utils/TableGen/RISCVVEmitter.cpp

const std::string &getShortStr() {
     if (ShortStr.empty())
       initShortStr();
     return ShortStr;
   }
 
   bool isValid() const { return Valid; }
   bool isScalar() const { return Scale.hasValue() && Scale.getValue() == 0; }
   bool isVector() const { return Scale.hasValue() && Scale.getValue() != 0; }
+  bool isVector(unsigned Width) const {
+    return isVector() && ElementBitwidth == Width;
+  }
   bool isFloat() const { return ScalarType == ScalarTypeKind::Float; }
   bool isSignedInteger() const {
     return ScalarType == ScalarTypeKind::SignedInteger;
   }
   bool isFloatVector(unsigned Width) const {
     return isVector() && isFloat() && ElementBitwidth == Width;
   }
   bool isFloat(unsigned Width) const {
private:
   // Compute and record a type string for used in the header.
   void initTypeStr();
   // Compute and record a short name of a type for C/C++ name suffix.
   void initShortStr();
 };
 
 using RVVTypePtr = RVVType *;
 using RVVTypes = std::vector<RVVTypePtr>;
+using RISCVPredefinedMacroT = uint8_t;
 
-enum RISCVExtension : uint8_t {
+enum RISCVPredefinedMacro : RISCVPredefinedMacroT {
   Basic = 0,
   F = 1 << 1,
   D = 1 << 2,
   Zfh = 1 << 3,
   RV64 = 1 << 4,
+  VectorMaxELen64 = 1 << 5,
+  VectorMaxELenFp32 = 1 << 6,
+  VectorMaxELenFp64 = 1 << 7,
 };
 
 // TODO refactor RVVIntrinsic class design after support all intrinsic
 // combination. This represents an instantiation of an intrinsic with a
 // particular type and prototype
 class RVVIntrinsic {
 
 private:
   std::string BuiltinName; // Builtin name
   std::string Name;        // C intrinsic name.
   std::string MangledName;
   std::string IRName;
   bool IsMask;
   bool HasVL;
   bool HasPolicy;
   bool HasNoMaskedOverloaded;
   bool HasAutoDef; // There is automiatic definition in header
   std::string ManualCodegen;
   RVVTypePtr OutputType; // Builtin output type
   RVVTypes InputTypes;   // Builtin input types
   // The types we use to obtain the specific LLVM intrinsic. They are index of
   // InputTypes. -1 means the return type.
   std::vector<int64_t> IntrinsicTypes;
-  uint8_t RISCVExtensions = 0;
+  RISCVPredefinedMacroT RISCVPredefinedMacros = 0;
   unsigned NF = 1;
 
 public:
   RVVIntrinsic(StringRef Name, StringRef Suffix, StringRef MangledName,
                StringRef MangledSuffix, StringRef IRName, bool IsMask,
                bool HasMaskedOffOperand, bool HasVL, bool HasPolicy,
                bool HasNoMaskedOverloaded, bool HasAutoDef,
                StringRef ManualCodegen, const RVVTypes &Types,
                const std::vector<int64_t> &IntrinsicTypes,
                const std::vector<StringRef> &RequiredExtensions, unsigned NF);
   ~RVVIntrinsic() = default;
 
   StringRef getBuiltinName() const { return BuiltinName; }
   StringRef getName() const { return Name; }
   StringRef getMangledName() const { return MangledName; }
   bool hasVL() const { return HasVL; }
   bool hasPolicy() const { return HasPolicy; }
   bool hasNoMaskedOverloaded() const { return HasNoMaskedOverloaded; }
   bool hasManualCodegen() const { return !ManualCodegen.empty(); }
   bool hasAutoDef() const { return HasAutoDef; }
   bool isMask() const { return IsMask; }
   StringRef getIRName() const { return IRName; }
   StringRef getManualCodegen() const { return ManualCodegen; }
-  uint8_t getRISCVExtensions() const { return RISCVExtensions; }
+  RISCVPredefinedMacroT getRISCVPredefinedMacros() const {
+    return RISCVPredefinedMacros;
+  }
   unsigned getNF() const { return NF; }
   const std::vector<int64_t> &getIntrinsicTypes() const {
     return IntrinsicTypes;
   }
 
   // Return the type string for a BUILTIN() macro in Builtins.def.
   std::string getBuiltinTypeStr() const;
 
private:
   /// Emit Acrh predecessor definitions and body, assume the element of Defs are
   /// sorted by extension.
   void emitArchMacroAndBody(
       std::vector<std::unique_ptr<RVVIntrinsic>> &Defs, raw_ostream &o,
       std::function<void(raw_ostream &, const RVVIntrinsic &)>);
 
   // Emit the architecture preprocessor definitions. Return true when emits
   // non-empty string.
-  bool emitExtDefStr(uint8_t Extensions, raw_ostream &o);
+  bool emitMacroRestrictionStr(RISCVPredefinedMacroT PredefinedMacros, raw_ostream &o);
   // Slice Prototypes string into sub prototype string and process each sub
   // prototype string individually in the Handler.
   void parsePrototypes(StringRef Prototypes,
                        std::function<void(StringRef)> Handler);
 };
 
 } // namespace
 
if (!Suffix.empty())
     Name += "_" + Suffix.str();
   if (!MangledSuffix.empty())
     MangledName += "_" + MangledSuffix.str();
   if (IsMask) {
     BuiltinName += "_m";
     Name += "_m";
   }
 
   // Init RISC-V extensions
   for (const auto &T : OutInTypes) {
     if (T->isFloatVector(16) || T->isFloat(16))
-      RISCVExtensions |= RISCVExtension::Zfh;
-    else if (T->isFloatVector(32) || T->isFloat(32))
-      RISCVExtensions |= RISCVExtension::F;
-    else if (T->isFloatVector(64) || T->isFloat(64))
-      RISCVExtensions |= RISCVExtension::D;
+      RISCVPredefinedMacros |= RISCVPredefinedMacro::Zfh;
+    if (T->isFloatVector(32))
+      RISCVPredefinedMacros |= RISCVPredefinedMacro::VectorMaxELenFp32;
+    if (T->isFloatVector(64))
+      RISCVPredefinedMacros |= RISCVPredefinedMacro::VectorMaxELenFp64;
+    if (T->isVector(64))
+      RISCVPredefinedMacros |= RISCVPredefinedMacro::VectorMaxELen64;
   }
   for (auto Extension : RequiredExtensions) {
     if (Extension == "RV64")
-      RISCVExtensions |= RISCVExtension::RV64;
+      RISCVPredefinedMacros |= RISCVPredefinedMacro::RV64;
   }
 
   // Init OutputType and InputTypes
   OutputType = OutInTypes[0];
   InputTypes.assign(OutInTypes.begin() + 1, OutInTypes.end());
 
   // IntrinsicTypes is nonmasked version index. Need to update it
   // if there is maskedoff operand (It is always in first operand).
for (int Log2LMUL : Log2LMULs) {
     if (T.hasValue())
       printType(T.getValue());
   }
   OS << "#endif\n\n";
 
   // The same extension include in the same arch guard marco.
   llvm::stable_sort(Defs, [](const std::unique_ptr<RVVIntrinsic> &A,
                              const std::unique_ptr<RVVIntrinsic> &B) {
-    return A->getRISCVExtensions() < B->getRISCVExtensions();
+    return A->getRISCVPredefinedMacros() < B->getRISCVPredefinedMacros();
   });
 
   OS << "#define __rvv_ai static __inline__\n";
 
   // Print intrinsic functions with macro
   emitArchMacroAndBody(Defs, OS, [](raw_ostream &OS, const RVVIntrinsic &Inst) {
     OS << "__rvv_ai ";
     Inst.emitIntrinsicFuncDef(OS);
Optional<RVVTypePtr> RVVEmitter::computeType(BasicType BT, int Log2LMUL,
   // Record illegal type index.
   IllegalTypes.insert(Idx);
   return llvm::None;
 }
 
 void RVVEmitter::emitArchMacroAndBody(
     std::vector<std::unique_ptr<RVVIntrinsic>> &Defs, raw_ostream &OS,
     std::function<void(raw_ostream &, const RVVIntrinsic &)> PrintBody) {
-  uint8_t PrevExt = (*Defs.begin())->getRISCVExtensions();
-  bool NeedEndif = emitExtDefStr(PrevExt, OS);
+  RISCVPredefinedMacroT PrevMacros = (*Defs.begin())->getRISCVPredefinedMacros();
+  bool NeedEndif = emitMacroRestrictionStr(PrevMacros, OS);
   for (auto &Def : Defs) {
-    uint8_t CurExt = Def->getRISCVExtensions();
-    if (CurExt != PrevExt) {
+    RISCVPredefinedMacroT CurMacros = Def->getRISCVPredefinedMacros();
+    if (CurMacros != PrevMacros) {
       if (NeedEndif)
         OS << "#endif\n\n";
-      NeedEndif = emitExtDefStr(CurExt, OS);
-      PrevExt = CurExt;
+      NeedEndif = emitMacroRestrictionStr(CurMacros, OS);
+      PrevMacros = CurMacros;
     }
     if (Def->hasAutoDef())
       PrintBody(OS, *Def);
   }
   if (NeedEndif)
     OS << "#endif\n\n";
 }
 
-bool RVVEmitter::emitExtDefStr(uint8_t Extents, raw_ostream &OS) {
-  if (Extents == RISCVExtension::Basic)
+bool RVVEmitter::emitMacroRestrictionStr(RISCVPredefinedMacroT PredefinedMacros,
+                               raw_ostream &OS) {
+  if (PredefinedMacros == RISCVPredefinedMacro::Basic)
     return false;
   OS << "#if ";
   ListSeparator LS(" && ");
-  if (Extents & RISCVExtension::F)
+  if (PredefinedMacros & RISCVPredefinedMacro::F)
     OS << LS << "defined(__riscv_f)";
-  if (Extents & RISCVExtension::D)
+  if (PredefinedMacros & RISCVPredefinedMacro::D)
     OS << LS << "defined(__riscv_d)";
-  if (Extents & RISCVExtension::Zfh)
+  if (PredefinedMacros & RISCVPredefinedMacro::Zfh)
     OS << LS << "defined(__riscv_zfh)";
-  if (Extents & RISCVExtension::RV64)
+  if (PredefinedMacros & RISCVPredefinedMacro::RV64)
     OS << LS << "(__riscv_xlen == 64)";
+  if (PredefinedMacros & RISCVPredefinedMacro::VectorMaxELen64)
+    OS << LS << "(__riscv_v_elen >= 64)";
+  if (PredefinedMacros & RISCVPredefinedMacro::VectorMaxELenFp32)
+    OS << LS << "(__riscv_v_elen_fp >= 32)";
+  if (PredefinedMacros & RISCVPredefinedMacro::VectorMaxELenFp64)
+    OS << LS << "(__riscv_v_elen_fp >= 64)";
   OS << "\n";
   return true;
 }
 
 namespace clang {
 void EmitRVVHeader(RecordKeeper &Records, raw_ostream &OS) {
   RVVEmitter(Records).createHeader(OS);
 }