llvm-project/llvm/lib/Target/AMDGPU/AMDGPUArgumentUsageInfo.cpp

//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

#include "AMDGPUArgumentUsageInfo.h"
#include "AMDGPU.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "SIRegisterInfo.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/Support/NativeFormatting.h"
#include "llvm/Support/raw_ostream.h"

using namespace llvm;

void ArgDescriptor::print(raw_ostream &OS,
                          const TargetRegisterInfo *TRI) const {
  if (!isSet()) {
    OS << "<not set>\n";
    return;
  }

  if (isRegister())
    OS << "Reg " << printReg(getRegister(), TRI);
  else
    OS << "Stack offset " << getStackOffset();

  if (isMasked()) {
    OS << " & ";
    llvm::write_hex(OS, Mask, llvm::HexPrintStyle::PrefixLower);
  }

  OS << '\n';
}

// Hardcoded registers from fixed function ABI
const AMDGPUFunctionArgInfo AMDGPUFunctionArgInfo::FixedABIFunctionInfo =
    AMDGPUFunctionArgInfo::fixedABILayout();

std::tuple<const ArgDescriptor *, const TargetRegisterClass *, LLT>
AMDGPUFunctionArgInfo::getPreloadedValue(
    AMDGPUFunctionArgInfo::PreloadedValue Value) const {
  switch (Value) {
  case AMDGPUFunctionArgInfo::PRIVATE_SEGMENT_BUFFER: {
    return std::tuple(PrivateSegmentBuffer ? &PrivateSegmentBuffer : nullptr,
                      &AMDGPU::SGPR_128RegClass, LLT::fixed_vector(4, 32));
  }
  case AMDGPUFunctionArgInfo::IMPLICIT_BUFFER_PTR:
    return std::tuple(ImplicitBufferPtr ? &ImplicitBufferPtr : nullptr,
                      &AMDGPU::SGPR_64RegClass,
                      LLT::pointer(AMDGPUAS::CONSTANT_ADDRESS, 64));
  case AMDGPUFunctionArgInfo::WORKGROUP_ID_X:
    return std::tuple(WorkGroupIDX ? &WorkGroupIDX : nullptr,
                      &AMDGPU::SGPR_32RegClass, LLT::scalar(32));
  case AMDGPUFunctionArgInfo::WORKGROUP_ID_Y:
    return std::tuple(WorkGroupIDY ? &WorkGroupIDY : nullptr,
                      &AMDGPU::SGPR_32RegClass, LLT::scalar(32));
  case AMDGPUFunctionArgInfo::WORKGROUP_ID_Z:
    return std::tuple(WorkGroupIDZ ? &WorkGroupIDZ : nullptr,
                      &AMDGPU::SGPR_32RegClass, LLT::scalar(32));
  case AMDGPUFunctionArgInfo::CLUSTER_WORKGROUP_ID_X:
  case AMDGPUFunctionArgInfo::CLUSTER_WORKGROUP_ID_Y:
  case AMDGPUFunctionArgInfo::CLUSTER_WORKGROUP_ID_Z:
  case AMDGPUFunctionArgInfo::CLUSTER_WORKGROUP_MAX_ID_X:
  case AMDGPUFunctionArgInfo::CLUSTER_WORKGROUP_MAX_ID_Y:
  case AMDGPUFunctionArgInfo::CLUSTER_WORKGROUP_MAX_ID_Z:
  case AMDGPUFunctionArgInfo::CLUSTER_WORKGROUP_MAX_FLAT_ID:
    return std::tuple(nullptr, &AMDGPU::SGPR_32RegClass, LLT::scalar(32));
  case AMDGPUFunctionArgInfo::LDS_KERNEL_ID:
    return std::tuple(LDSKernelId ? &LDSKernelId : nullptr,
                      &AMDGPU::SGPR_32RegClass, LLT::scalar(32));
  case AMDGPUFunctionArgInfo::PRIVATE_SEGMENT_WAVE_BYTE_OFFSET:
    return std::tuple(
        PrivateSegmentWaveByteOffset ? &PrivateSegmentWaveByteOffset : nullptr,
        &AMDGPU::SGPR_32RegClass, LLT::scalar(32));
  case AMDGPUFunctionArgInfo::PRIVATE_SEGMENT_SIZE:
    return {PrivateSegmentSize ? &PrivateSegmentSize : nullptr,
            &AMDGPU::SGPR_32RegClass, LLT::scalar(32)};
  case AMDGPUFunctionArgInfo::KERNARG_SEGMENT_PTR:
    return std::tuple(KernargSegmentPtr ? &KernargSegmentPtr : nullptr,
                      &AMDGPU::SGPR_64RegClass,
                      LLT::pointer(AMDGPUAS::CONSTANT_ADDRESS, 64));
  case AMDGPUFunctionArgInfo::IMPLICIT_ARG_PTR:
    return std::tuple(ImplicitArgPtr ? &ImplicitArgPtr : nullptr,
                      &AMDGPU::SGPR_64RegClass,
                      LLT::pointer(AMDGPUAS::CONSTANT_ADDRESS, 64));
  case AMDGPUFunctionArgInfo::DISPATCH_ID:
    return std::tuple(DispatchID ? &DispatchID : nullptr,
                      &AMDGPU::SGPR_64RegClass, LLT::scalar(64));
  case AMDGPUFunctionArgInfo::FLAT_SCRATCH_INIT:
    return std::tuple(FlatScratchInit ? &FlatScratchInit : nullptr,
                      &AMDGPU::SGPR_64RegClass, LLT::scalar(64));
  case AMDGPUFunctionArgInfo::DISPATCH_PTR:
    return std::tuple(DispatchPtr ? &DispatchPtr : nullptr,
                      &AMDGPU::SGPR_64RegClass,
                      LLT::pointer(AMDGPUAS::CONSTANT_ADDRESS, 64));
  case AMDGPUFunctionArgInfo::QUEUE_PTR:
    return std::tuple(QueuePtr ? &QueuePtr : nullptr, &AMDGPU::SGPR_64RegClass,
                      LLT::pointer(AMDGPUAS::CONSTANT_ADDRESS, 64));
  case AMDGPUFunctionArgInfo::WORKITEM_ID_X:
    return std::tuple(WorkItemIDX ? &WorkItemIDX : nullptr,
                      &AMDGPU::VGPR_32RegClass, LLT::scalar(32));
  case AMDGPUFunctionArgInfo::WORKITEM_ID_Y:
    return std::tuple(WorkItemIDY ? &WorkItemIDY : nullptr,
                      &AMDGPU::VGPR_32RegClass, LLT::scalar(32));
  case AMDGPUFunctionArgInfo::WORKITEM_ID_Z:
    return std::tuple(WorkItemIDZ ? &WorkItemIDZ : nullptr,
                      &AMDGPU::VGPR_32RegClass, LLT::scalar(32));
  }
  llvm_unreachable("unexpected preloaded value type");
}

AMDGPUFunctionArgInfo AMDGPUFunctionArgInfo::fixedABILayout() {
  AMDGPUFunctionArgInfo AI;
  AI.PrivateSegmentBuffer
    = ArgDescriptor::createRegister(AMDGPU::SGPR0_SGPR1_SGPR2_SGPR3);
  AI.DispatchPtr = ArgDescriptor::createRegister(AMDGPU::SGPR4_SGPR5);
  AI.QueuePtr = ArgDescriptor::createRegister(AMDGPU::SGPR6_SGPR7);

  // Do not pass kernarg segment pointer, only pass increment version in its
  // place.
  AI.ImplicitArgPtr = ArgDescriptor::createRegister(AMDGPU::SGPR8_SGPR9);
  AI.DispatchID = ArgDescriptor::createRegister(AMDGPU::SGPR10_SGPR11);

  // Skip FlatScratchInit/PrivateSegmentSize
  AI.WorkGroupIDX = ArgDescriptor::createRegister(AMDGPU::SGPR12);
  AI.WorkGroupIDY = ArgDescriptor::createRegister(AMDGPU::SGPR13);
  AI.WorkGroupIDZ = ArgDescriptor::createRegister(AMDGPU::SGPR14);
  AI.LDSKernelId = ArgDescriptor::createRegister(AMDGPU::SGPR15);

  const unsigned Mask = 0x3ff;
  AI.WorkItemIDX = ArgDescriptor::createRegister(AMDGPU::VGPR31, Mask);
  AI.WorkItemIDY = ArgDescriptor::createRegister(AMDGPU::VGPR31, Mask << 10);
  AI.WorkItemIDZ = ArgDescriptor::createRegister(AMDGPU::VGPR31, Mask << 20);
  return AI;
}