llvm-project/llvm/lib/Target/AMDGPU/AMDGPUHSAMetadataStreamer.h
Matt Arsenault 0d2c55cb96
AMDGPU: Move enqueued block handling into clang (#128519)
The previous implementation wasn't maintaining a faithful IR
representation of how this really works. The value returned by
createEnqueuedBlockKernel wasn't actually used as a function, and
hacked up later to be a pointer to the runtime handle global
variable. In reality, the enqueued block is a struct where the first
field is a pointer to the kernel descriptor, not the kernel itself. We
were also relying on passing around a reference to a global using a
string attribute containing its name. It's better to base this on a
proper IR symbol reference during final emission.

This now avoids using a function attribute on kernels and avoids using
the additional "runtime-handle" attribute to populate the final
metadata. Instead, associate the runtime handle reference to the
kernel with the !associated global metadata. We can then get a final,
correctly mangled name at the end.

I couldn't figure out how to get rename-with-external-symbol behavior
using a combination of comdats and aliases, so leaves an IR pass to
externalize the runtime handles for codegen. If anything breaks, it's
most likely this, so leave avoiding this for a later step. Use a
special section name to enable this behavior. This also means it's
possible to declare enqueuable kernels in source without going through
the dedicated block syntax or other dedicated compiler support.

We could move towards initializing the runtime handle in the
compiler/linker. I have a working patch where the linker sets up the
first field of the handle, avoiding the need to export the block
kernel symbol for the runtime. We would need new relocations to get
the private and group sizes, but that would avoid the runtime's
special case handling that requires the device_enqueue_symbol metadata
field.

https://reviews.llvm.org/D141700
2025-03-10 19:54:04 +07:00

174 lines
5.4 KiB
C++

//===--- AMDGPUHSAMetadataStreamer.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
//
//===----------------------------------------------------------------------===//
//
/// \file
/// AMDGPU HSA Metadata Streamer.
///
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_AMDGPU_MCTARGETDESC_AMDGPUHSAMETADATASTREAMER_H
#define LLVM_LIB_TARGET_AMDGPU_MCTARGETDESC_AMDGPUHSAMETADATASTREAMER_H
#include "Utils/AMDGPUDelayedMCExpr.h"
#include "llvm/BinaryFormat/MsgPackDocument.h"
#include "llvm/Support/AMDGPUMetadata.h"
#include "llvm/Support/Alignment.h"
#include "llvm/Support/Compiler.h"
namespace llvm {
class AMDGPUTargetMachine;
class AMDGPUTargetStreamer;
class Argument;
class DataLayout;
class Function;
class MachineFunction;
class MDNode;
class Module;
struct SIProgramInfo;
class Type;
namespace AMDGPU {
namespace IsaInfo {
class AMDGPUTargetID;
}
namespace HSAMD {
class MetadataStreamer {
public:
virtual ~MetadataStreamer() = default;
virtual bool emitTo(AMDGPUTargetStreamer &TargetStreamer) = 0;
virtual void begin(const Module &Mod,
const IsaInfo::AMDGPUTargetID &TargetID) = 0;
virtual void end() = 0;
virtual void emitKernel(const MachineFunction &MF,
const SIProgramInfo &ProgramInfo) = 0;
protected:
virtual void emitVersion() = 0;
virtual void emitHiddenKernelArgs(const MachineFunction &MF, unsigned &Offset,
msgpack::ArrayDocNode Args) = 0;
virtual void emitKernelAttrs(const AMDGPUTargetMachine &TM,
const Function &Func,
msgpack::MapDocNode Kern) = 0;
};
class LLVM_EXTERNAL_VISIBILITY MetadataStreamerMsgPackV4
: public MetadataStreamer {
protected:
std::unique_ptr<DelayedMCExprs> DelayedExprs =
std::make_unique<DelayedMCExprs>();
std::unique_ptr<msgpack::Document> HSAMetadataDoc =
std::make_unique<msgpack::Document>();
void dump(StringRef HSAMetadataString) const;
void verify(StringRef HSAMetadataString) const;
std::optional<StringRef> getAccessQualifier(StringRef AccQual) const;
std::optional<StringRef>
getAddressSpaceQualifier(unsigned AddressSpace) const;
StringRef getValueKind(Type *Ty, StringRef TypeQual,
StringRef BaseTypeName) const;
std::string getTypeName(Type *Ty, bool Signed) const;
msgpack::ArrayDocNode getWorkGroupDimensions(MDNode *Node) const;
msgpack::MapDocNode getHSAKernelProps(const MachineFunction &MF,
const SIProgramInfo &ProgramInfo,
unsigned CodeObjectVersion) const;
void emitVersion() override;
void emitTargetID(const IsaInfo::AMDGPUTargetID &TargetID);
void emitPrintf(const Module &Mod);
void emitKernelLanguage(const Function &Func, msgpack::MapDocNode Kern);
void emitKernelAttrs(const AMDGPUTargetMachine &TM, const Function &Func,
msgpack::MapDocNode Kern) override;
void emitKernelArgs(const MachineFunction &MF, msgpack::MapDocNode Kern);
void emitKernelArg(const Argument &Arg, unsigned &Offset,
msgpack::ArrayDocNode Args);
void emitKernelArg(const DataLayout &DL, Type *Ty, Align Alignment,
StringRef ValueKind, unsigned &Offset,
msgpack::ArrayDocNode Args,
MaybeAlign PointeeAlign = std::nullopt,
StringRef Name = "", StringRef TypeName = "",
StringRef BaseTypeName = "", StringRef ActAccQual = "",
StringRef AccQual = "", StringRef TypeQual = "");
void emitHiddenKernelArgs(const MachineFunction &MF, unsigned &Offset,
msgpack::ArrayDocNode Args) override;
msgpack::DocNode &getRootMetadata(StringRef Key) {
return HSAMetadataDoc->getRoot().getMap(/*Convert=*/true)[Key];
}
msgpack::DocNode &getHSAMetadataRoot() {
return HSAMetadataDoc->getRoot();
}
public:
MetadataStreamerMsgPackV4() = default;
~MetadataStreamerMsgPackV4() = default;
bool emitTo(AMDGPUTargetStreamer &TargetStreamer) override;
void begin(const Module &Mod,
const IsaInfo::AMDGPUTargetID &TargetID) override;
void end() override;
void emitKernel(const MachineFunction &MF,
const SIProgramInfo &ProgramInfo) override;
};
class MetadataStreamerMsgPackV5 : public MetadataStreamerMsgPackV4 {
protected:
void emitVersion() override;
void emitHiddenKernelArgs(const MachineFunction &MF, unsigned &Offset,
msgpack::ArrayDocNode Args) override;
void emitKernelAttrs(const AMDGPUTargetMachine &TM, const Function &Func,
msgpack::MapDocNode Kern) override;
public:
MetadataStreamerMsgPackV5() = default;
~MetadataStreamerMsgPackV5() = default;
};
class MetadataStreamerMsgPackV6 final : public MetadataStreamerMsgPackV5 {
protected:
void emitVersion() override;
public:
MetadataStreamerMsgPackV6() = default;
~MetadataStreamerMsgPackV6() = default;
};
} // end namespace HSAMD
} // end namespace AMDGPU
} // end namespace llvm
#endif // LLVM_LIB_TARGET_AMDGPU_MCTARGETDESC_AMDGPUHSAMETADATASTREAMER_H