NVPTXUtilities.h

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//===-- NVPTXUtilities - Utilities -----------------------------*- C++ -*-====//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains declarations for PTX-specific utility functions.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_LIB_TARGET_NVPTX_NVPTXUTILITIES_H
#define LLVM_LIB_TARGET_NVPTX_NVPTXUTILITIES_H
 
#include "NVPTX.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Alignment.h"
#include "llvm/Support/FormatVariadic.h"
#include <cstdarg>
#include <string>
 
namespace llvm {
 
class DataLayout;
class TargetMachine;
 
Function *getMaybeBitcastedCallee(const CallBase *CB);
 
/// Since function arguments are passed via .param space, we may want to
/// increase their alignment in a way that ensures that we can effectively
/// vectorize their loads & stores. We can increase alignment only if the
/// function has internal or private linkage as for other linkage types callers
/// may already rely on default alignment. To allow using 128-bit vectorized
/// loads/stores, this function ensures that alignment is 16 or greater.
Align getPTXPromotedParamTypeAlign(const Function *F, Type *ArgTy,
                                   const DataLayout &DL);
 
Align getDeviceByValParamAlign(const Function *F, Type *ArgTy,
                               Align InitialAlign, const DataLayout &DL);
 
/// Get the alignment for a function parameter or return value.
/// \p AttrIdx is the AttributeList index (e.g. FirstArgIndex + argNo, or
/// ReturnIndex for return values). Checks for an explicit alignment attribute,
/// then falls back to getPromotedParamTypeAlign, incorporating byval param
/// alignment when applicable.
Align getPTXParamAlign(const Function *F, Type *Ty, unsigned AttrIdx,
                       const DataLayout &DL);
 
/// Get the alignment for a call-site argument or return value. Resolves the
/// callee and delegates to the Function overload of getParamAlign. For
/// indirect calls with no resolvable callee, falls back to
/// getPromotedParamTypeAlign.
Align getPTXParamAlign(const CallBase *CB, Type *Ty, unsigned AttrIdx,
                       const DataLayout &DL);
 
// PTX ABI requires all scalar argument/return values to have
// bit-size as a power of two of at least 32 bits.
inline unsigned promoteScalarArgumentSize(unsigned size) {
  if (size <= 32)
    return 32;
  if (size <= 64)
    return 64;
  if (size <= 128)
    return 128;
  return size;
}
 
bool shouldEmitPTXNoReturn(const Value *V, const TargetMachine &TM);
 
inline bool shouldPassAsArray(Type *Ty) {
  return Ty->isAggregateType() || Ty->isVectorTy() ||
         Ty->getScalarSizeInBits() >= 128 || Ty->isHalfTy() || Ty->isBFloatTy();
}
 
namespace NVPTX {
// Returns a list of vector types that we prefer to fit into a single PTX
// register. NOTE: This must be kept in sync with the register classes
// defined in NVPTXRegisterInfo.td.
inline auto packed_types() {
  static const auto PackedTypes = {MVT::v4i8,  MVT::v2f16, MVT::v2bf16,
                                   MVT::v2i16, MVT::v2f32, MVT::v2i32};
  return PackedTypes;
}
 
// Checks if the type VT can fit into a single register.
inline bool isPackedVectorTy(EVT VT) {
  return any_of(packed_types(), equal_to(VT));
}
 
// Checks if two or more of the type ET can fit into a single register.
inline bool isPackedElementTy(EVT ET) {
  return any_of(packed_types(),
                [ET](EVT OVT) { return OVT.getVectorElementType() == ET; });
}
 
inline std::string getValidPTXIdentifier(StringRef Name) {
  std::string ValidName;
  ValidName.reserve(Name.size() + 4);
  for (char C : Name)
    // While PTX also allows '%' at the start of identifiers, LLVM will throw a
    // fatal error for '%' in symbol names in MCSymbol::print. Exclude for now.
    if (isAlnum(C) || C == '_' || C == '$')
      ValidName.push_back(C);
    else
      ValidName.append({'_', '$', '_'});
 
  return ValidName;
}
 
inline std::string OrderingToString(Ordering Order) {
  switch (Order) {
  case Ordering::NotAtomic:
    return "NotAtomic";
  case Ordering::Relaxed:
    return "Relaxed";
  case Ordering::Acquire:
    return "Acquire";
  case Ordering::Release:
    return "Release";
  case Ordering::AcquireRelease:
    return "AcquireRelease";
  case Ordering::SequentiallyConsistent:
    return "SequentiallyConsistent";
  case Ordering::Volatile:
    return "Volatile";
  case Ordering::RelaxedMMIO:
    return "RelaxedMMIO";
  }
  report_fatal_error(formatv("Unknown NVPTX::Ordering \"{}\".",
                             static_cast<OrderingUnderlyingType>(Order)));
}
 
inline raw_ostream &operator<<(raw_ostream &O, Ordering Order) {
  O << OrderingToString(Order);
  return O;
}
 
inline std::string ScopeToString(Scope S) {
  switch (S) {
  case Scope::Thread:
    return "Thread";
  case Scope::System:
    return "System";
  case Scope::Block:
    return "Block";
  case Scope::Cluster:
    return "Cluster";
  case Scope::Device:
    return "Device";
  case Scope::DefaultDevice:
    return "DefaultDevice";
  }
  report_fatal_error(formatv("Unknown NVPTX::Scope \"{}\".",
                             static_cast<ScopeUnderlyingType>(S)));
}
 
inline raw_ostream &operator<<(raw_ostream &O, Scope S) {
  O << ScopeToString(S);
  return O;
}
 
inline const char *addressSpaceToString(AddressSpace A,
                                        bool UseParamSubqualifiers = false) {
  switch (A) {
  case AddressSpace::Generic:
    return "generic";
  case AddressSpace::Global:
    return "global";
  case AddressSpace::Const:
    return "const";
  case AddressSpace::Shared:
    return "shared";
  case AddressSpace::SharedCluster:
    return "shared::cluster";
  case AddressSpace::EntryParam:
    return UseParamSubqualifiers ? "param::entry" : "param";
  case AddressSpace::DeviceParam:
    return UseParamSubqualifiers ? "param::func" : "param";
  case AddressSpace::Local:
    return "local";
  }
  report_fatal_error(formatv("Unknown NVPTX::AddressSpace \"{}\".",
                             static_cast<AddressSpaceUnderlyingType>(A)));
}
 
inline raw_ostream &operator<<(raw_ostream &O, AddressSpace A) {
  O << addressSpaceToString(A);
  return O;
}
 
} // namespace NVPTX
} // namespace llvm
 
#endif