lib/ArgKind.h

// Copyright 2017 The Clspv Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef CLSPV_LIB_ARGKIND_H_
#define CLSPV_LIB_ARGKIND_H_

#include "llvm/IR/Function.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/ADT/DenseMap.h"

namespace clspv {

enum class ArgKind : int {
  Buffer,
  Local,
  Pod,
  ReadOnlyImage,
  WriteOnlyImage,
  Sampler,
};

// Maps an LLVM type for a kernel argument to an argument kind.
ArgKind GetArgKindForType(llvm::Type *type);

// Converts an ArgKind to its string name.
const char* GetArgKindName(ArgKind);

// Maps an LLVM type for a kernel argument to an argument
// kind suitable for a descriptor map.  The result is one of:
//   buffer   - storage buffer
//   local    - array in Workgroup storage, number of elements given by
//              a specialization constant
//   pod      - plain-old-data
//   ro_image - read-only image
//   wo_image - write-only image
//   sampler  - sampler
inline const char *GetArgKindNameForType(llvm::Type *type) {
  return GetArgKindName(GetArgKindForType(type));
}

// Returns true if the given type is a pointer-to-local type.
bool IsLocalPtr(llvm::Type* type);

// Returns true if the given type is a sampler type.  If it is, then the
// struct type is sent back through the ptr argument.
bool IsSamplerType(llvm::Type *type, llvm::Type **struct_type_ptr = nullptr);

// Returns true if the given type is a image type.  If it is, then the
// struct type is sent back through the ptr argument.
bool IsImageType(llvm::Type *type, llvm::Type **struct_type_ptr = nullptr);

using ArgIdMapType = llvm::DenseMap<const llvm::Argument*, int>;

// Returns a mapping from pointer-to-local Argument to a specialization constant
// ID for that argument's array size.  The lowest value allocated is 3.
//
// The mapping is as follows:
// - The first index used is 3.
// - There are no gaps in the list of used indices.
// - Arguments from earlier kernel bodies have lower indices than arguments from
//   later kernel bodies.
// - Lower-numbered arguments have lower indices than higher-numbered arguments
//   in the same function.
// Note that this mapping is stable as long as the order of kernel bodies is
// retained, and the number and order of pointer-to-local arguments is retained.
ArgIdMapType AllocateArgSpecIds(llvm::Module &M);

} // namespace clspv

#endif