Files
clang-p2996/llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.h
Jon Chesterfield 3a20597776 [amdgpu] Implement lds kernel id intrinsic
Implement an intrinsic for use lowering LDS variables to different
addresses from different kernels. This will allow kernels that cannot
reach an LDS variable to avoid wasting space for it.

There are a number of implicit arguments accessed by intrinsic already
so this implementation closely follows the existing handling. It is slightly
novel in that this SGPR is written by the kernel prologue.

It is necessary in the general case to put variables at different addresses
such that they can be compactly allocated and thus necessary for an
indirect function call to have some means of determining where a
given variable was allocated. Claiming an arbitrary SGPR into which
an integer can be written by the kernel, in this implementation based
on metadata associated with that kernel, which is then passed on to
indirect call sites is sufficient to determine the variable address.

The intent is to emit a __const array of LDS addresses and index into it.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D125060
2022-07-19 17:46:19 +01:00

117 lines
3.3 KiB
C++

//===-- AMDGPUMachineFunctionInfo.h -------------------------------*- 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
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_AMDGPU_AMDGPUMACHINEFUNCTION_H
#define LLVM_LIB_TARGET_AMDGPU_AMDGPUMACHINEFUNCTION_H
#include "Utils/AMDGPUBaseInfo.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/Optional.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
namespace llvm {
class AMDGPUMachineFunction : public MachineFunctionInfo {
/// A map to keep track of local memory objects and their offsets within the
/// local memory space.
SmallDenseMap<const GlobalValue *, unsigned, 4> LocalMemoryObjects;
protected:
uint64_t ExplicitKernArgSize = 0; // Cache for this.
Align MaxKernArgAlign; // Cache for this.
/// Number of bytes in the LDS that are being used.
uint32_t LDSSize = 0;
uint32_t GDSSize = 0;
/// Number of bytes in the LDS allocated statically. This field is only used
/// in the instruction selector and not part of the machine function info.
uint32_t StaticLDSSize = 0;
uint32_t StaticGDSSize = 0;
/// Align for dynamic shared memory if any. Dynamic shared memory is
/// allocated directly after the static one, i.e., LDSSize. Need to pad
/// LDSSize to ensure that dynamic one is aligned accordingly.
/// The maximal alignment is updated during IR translation or lowering
/// stages.
Align DynLDSAlign;
// State of MODE register, assumed FP mode.
AMDGPU::SIModeRegisterDefaults Mode;
// Kernels + shaders. i.e. functions called by the hardware and not called
// by other functions.
bool IsEntryFunction = false;
// Entry points called by other functions instead of directly by the hardware.
bool IsModuleEntryFunction = false;
bool NoSignedZerosFPMath = false;
// Function may be memory bound.
bool MemoryBound = false;
// Kernel may need limited waves per EU for better performance.
bool WaveLimiter = false;
public:
AMDGPUMachineFunction(const MachineFunction &MF);
uint64_t getExplicitKernArgSize() const {
return ExplicitKernArgSize;
}
Align getMaxKernArgAlign() const { return MaxKernArgAlign; }
uint32_t getLDSSize() const {
return LDSSize;
}
uint32_t getGDSSize() const {
return GDSSize;
}
AMDGPU::SIModeRegisterDefaults getMode() const {
return Mode;
}
bool isEntryFunction() const {
return IsEntryFunction;
}
bool isModuleEntryFunction() const { return IsModuleEntryFunction; }
bool hasNoSignedZerosFPMath() const {
return NoSignedZerosFPMath;
}
bool isMemoryBound() const {
return MemoryBound;
}
bool needsWaveLimiter() const {
return WaveLimiter;
}
unsigned allocateLDSGlobal(const DataLayout &DL, const GlobalVariable &GV);
void allocateModuleLDSGlobal(const Function &F);
static Optional<uint32_t> getLDSKernelIdMetadata(const Function &F);
Align getDynLDSAlign() const { return DynLDSAlign; }
void setDynLDSAlign(const DataLayout &DL, const GlobalVariable &GV);
};
}
#endif