SPIRVToOCL.h

//===- SPIRVToOCL.h - Converts SPIR-V to LLVM ------------------*- C++ -*-===//
//
//                     The LLVM/SPIR-V Translator
//
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// License. See LICENSE.TXT for details.
//
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//===----------------------------------------------------------------------===//
/// \file
///
/// This file contains declaration of SPIRVToOCL class which implements
/// common transform of SPIR-V builtins to OCL builtins.
///
//===----------------------------------------------------------------------===//

#include "OCLUtil.h"
#include "SPIRVInternal.h"
#include "llvm/IR/InstVisitor.h"
#include "llvm/Pass.h"

#include <string>

namespace SPIRV {
class SPIRVToOCL : public ModulePass, public InstVisitor<SPIRVToOCL> {
protected:
  SPIRVToOCL(char &ID) : ModulePass(ID), M(nullptr), Ctx(nullptr) {}

public:
  virtual bool runOnModule(Module &M) = 0;

  void visitCallInst(CallInst &CI);

  // SPIR-V reader should translate vector casts into OCL built-ins because
  // such conversions are not defined neither by OpenCL C/C++ nor
  // by SPIR 1.2/2.0 standards. So, it is safer to convert such casts into
  // appropriate calls to conversion built-ins defined by the standards.
  void visitCastInst(CastInst &CI);

  /// Transform __spirv_ImageQuerySize[Lod] into vector of the same length
  /// containing {[get_image_width | get_image_dim], get_image_array_size}
  /// for all images except image1d_t which is always converted into
  /// get_image_width returning scalar result.
  void visitCallSPRIVImageQuerySize(CallInst *CI);

  /// Transform __spirv_(NonUniform)Group* to {work_group|sub_group}_*.
  ///
  /// Special handling of work_group_broadcast.
  ///   __spirv_GroupBroadcast(a, vec3(x, y, z))
  ///     =>
  ///   work_group_broadcast(a, x, y, z)
  ///
  /// Special handling of sub_group_all, sub_group_any,
  /// sub_group_non_uniform_all, sub_group_non_uniform_any, sub_group_ballot,
  /// sub_group_clustered_logical_[and/or/xor].
  ///   retTy func(i1 arg)
  ///     =>
  ///   retTy func(i32 arg)
  ///
  /// Special handling of sub_group_all, sub_group_any,
  /// sub_group_non_uniform_all,
  /// sub_group_non_uniform_any, sub_group_non_uniform_all_equal.
  ///   i1 func
  ///     =>
  ///   i32 func
  void visitCallSPIRVGroupBuiltin(CallInst *CI, Op OC);

  /// Transform __spirv_{PipeOpName} to OCL pipe builtin functions.
  void visitCallSPIRVPipeBuiltin(CallInst *CI, Op OC);

  /// Transform __spirv_OpOpSubgroupImageMediaBlockReadINTEL =>
  ///  intel_sub_group_media_block_read
  ///           __spirv_OpSubgroupImageMediaBlockWriteINTEL =>
  ///  intel_sub_group_media_block_write
  void visitCallSPIRVImageMediaBlockBuiltin(CallInst *CI, Op OC);

  /// Transform __spirv_* builtins to OCL 2.0 builtins.
  /// No change with arguments.
  void visitCallSPIRVBuiltin(CallInst *CI, Op OC);

  /// Get prefix work_/sub_ for OCL group builtin functions.
  /// Assuming the first argument of \param CI is a constant integer for
  /// workgroup/subgroup scope enums.
  std::string getGroupBuiltinPrefix(CallInst *CI);

  /// Transform __spirv_OpAtomicCompareExchange and
  /// __spirv_OpAtomicCompareExchangeWeak
  virtual Instruction *visitCallSPIRVAtomicCmpExchg(CallInst *CI, Op OC) = 0;

  /// Transform __spirv_OpAtomicIIncrement/OpAtomicIDecrement to:
  /// - OCL2.0: atomic_fetch_add_explicit/atomic_fetch_sub_explicit
  /// - OCL1.2: atomic_inc/atomic_dec
  virtual Instruction *visitCallSPIRVAtomicIncDec(CallInst *CI, Op OC) = 0;

  /// Transform __spirv_Atomic* to atomic_*.
  ///   __spirv_Atomic*(atomic_op, scope, sema, ops, ...) =>
  ///      atomic_*(atomic_op, ops, ..., order(sema), map(scope))
  virtual Instruction *visitCallSPIRVAtomicBuiltin(CallInst *CI, Op OC) = 0;

  /// Transform __spirv_MemoryBarrier to:
  /// - OCL2.0: atomic_work_item_fence.__spirv_MemoryBarrier(scope, sema) =>
  ///       atomic_work_item_fence(flag(sema), order(sema), map(scope))
  /// - OCL1.2: mem_fence
  virtual void visitCallSPIRVMemoryBarrier(CallInst *CI) = 0;

  /// Transform __spirv_ControlBarrier to:
  /// - OCL2.0: work_group_barrier or sub_group barrier
  /// - OCL1.2: barrier
  virtual void visitCallSPIRVControlBarrier(CallInst *CI) = 0;

  /// Conduct generic mutations for all atomic builtins
  virtual CallInst *mutateCommonAtomicArguments(CallInst *CI, Op OC) = 0;

  /// Transform __spirv_Opcode to ocl-version specific builtin name
  /// using separate maps for OpenCL 1.2 and OpenCL 2.0
  virtual Instruction *mutateAtomicName(CallInst *CI, Op OC) = 0;

private:
  /// Transform uniform group opcode to corresponding OpenCL function name,
  /// example: GroupIAdd(Reduce) => group_iadd => work_group_reduce_add |
  /// sub_group_reduce_add
  std::string getUniformArithmeticBuiltinName(CallInst *CI, Op OC);
  /// Transform non-uniform group opcode to corresponding OpenCL function name,
  /// example: GroupNonUniformIAdd(Reduce) => group_non_uniform_iadd =>
  /// sub_group_non_uniform_reduce_add
  std::string getNonUniformArithmeticBuiltinName(CallInst *CI, Op OC);
  /// Transform ballot bit count opcode to corresponding OpenCL function name,
  /// example: GroupNonUniformBallotBitCount(Reduce) =>
  /// group_ballot_bit_count_iadd => sub_​group_​ballot_​bit_​count
  std::string getBallotBuiltinName(CallInst *CI, Op OC);
  /// Transform group opcode to corresponding OpenCL function name
  std::string groupOCToOCLBuiltinName(CallInst *CI, Op OC);

protected:
  Module *M;
  LLVMContext *Ctx;
};
} // namespace SPIRV