[clang] [HIP] Support compressing device binary (PR #67162)
via cfe-commits
cfe-commits at lists.llvm.org
Fri Sep 22 09:31:30 PDT 2023
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang-driver
<details>
<summary>Changes</summary>
Add option -f[no-]offload-compress to clang to enable/disable compression of device binary for HIP. By default it is disabled.
Add option -compress to clang-offload-bundler to enable compression of offload bundle. By default it is disabled.
When enabled, zstd or zlib is used for compression when available.
When disabled, it is NFC compared to previous behavior. The same offload bundle format is used as before.
Clang-offload-bundler automatically detects whether the input file to be unbundled is compressed and the compression method and decompress if necessary.
---
Patch is 36.32 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/67162.diff
8 Files Affected:
- (modified) clang/docs/ClangOffloadBundler.rst (+27)
- (modified) clang/include/clang/Driver/OffloadBundler.h (+37)
- (modified) clang/include/clang/Driver/Options.td (+4)
- (modified) clang/lib/Driver/OffloadBundler.cpp (+293-44)
- (modified) clang/lib/Driver/ToolChains/Clang.cpp (+7)
- (added) clang/test/Driver/clang-offload-bundler-zlib.c (+75)
- (added) clang/test/Driver/clang-offload-bundler-zstd.c (+72)
- (modified) clang/tools/clang-offload-bundler/ClangOffloadBundler.cpp (+10)
``````````diff
diff --git a/clang/docs/ClangOffloadBundler.rst b/clang/docs/ClangOffloadBundler.rst
index d08bf4b97781fa4..1e21d3e7264d5c3 100644
--- a/clang/docs/ClangOffloadBundler.rst
+++ b/clang/docs/ClangOffloadBundler.rst
@@ -309,3 +309,30 @@ target by comparing bundle ID's. Two bundle ID's are considered compatible if:
* Their offload kind are the same
* Their target triple are the same
* Their GPUArch are the same
+
+Compression and Decompression
+=============================
+
+``clang-offload-bundler`` provides features to compress and decompress the full
+bundle, leveraging inherent redundancies within the bundle entries. Use the
+`-compress` command-line option to enable this compression capability.
+
+The compressed offload bundle begins with a header followed by the compressed binary data:
+
+- **Magic Number (4 bytes)**:
+ This is a unique identifier to distinguish compressed offload bundles. The value is the string 'CCOB' (Compressed Clang Offload Bundle).
+
+- **Version Number (16-bit unsigned int)**:
+ This denotes the version of the compressed offload bundle format. The current version is `1`.
+
+- **Compression Method (16-bit unsigned int)**:
+ This field indicates the compression method used. The value corresponds to either `zlib` or `zstd`, represented as a 16-bit unsigned integer cast from the LLVM compression enumeration.
+
+- **Uncompressed Binary Size (32-bit unsigned int)**:
+ This is the size (in bytes) of the binary data before it was compressed.
+
+- **Hash (64-bit unsigned int)**:
+ This is a 64-bit truncated MD5 hash of the uncompressed binary data. It serves for verification and caching purposes.
+
+- **Compressed Data**:
+ The actual compressed binary data follows the header. Its size can be inferred from the total size of the file minus the header size.
diff --git a/clang/include/clang/Driver/OffloadBundler.h b/clang/include/clang/Driver/OffloadBundler.h
index 28473c53662de2c..17df31d31071d99 100644
--- a/clang/include/clang/Driver/OffloadBundler.h
+++ b/clang/include/clang/Driver/OffloadBundler.h
@@ -19,6 +19,7 @@
#include "llvm/Support/Error.h"
#include "llvm/TargetParser/Triple.h"
+#include <llvm/Support/MemoryBuffer.h>
#include <string>
#include <vector>
@@ -26,11 +27,15 @@ namespace clang {
class OffloadBundlerConfig {
public:
+ OffloadBundlerConfig();
+
bool AllowNoHost = false;
bool AllowMissingBundles = false;
bool CheckInputArchive = false;
bool PrintExternalCommands = false;
bool HipOpenmpCompatible = false;
+ bool Compress = false;
+ bool Verbose = false;
unsigned BundleAlignment = 1;
unsigned HostInputIndex = ~0u;
@@ -84,6 +89,38 @@ struct OffloadTargetInfo {
std::string str() const;
};
+// CompressedOffloadBundle represents the format for the compressed offload
+// bundles.
+//
+// The format is as follows:
+// - Magic Number (4 bytes) - A constant "CCOB".
+// - Version (2 bytes)
+// - Compression Method (2 bytes) - Uses the values from
+// llvm::compression::Format.
+// - Uncompressed Size (4 bytes).
+// - Truncated MD5 Hash (8 bytes).
+// - Compressed Data (variable length).
+
+class CompressedOffloadBundle {
+private:
+ static inline const size_t MagicSize = 4;
+ static inline const size_t VersionFieldSize = sizeof(uint16_t);
+ static inline const size_t MethodFieldSize = sizeof(uint16_t);
+ static inline const size_t SizeFieldSize = sizeof(uint32_t);
+ static inline const size_t HashFieldSize = 8;
+ static inline const size_t HeaderSize = MagicSize + VersionFieldSize +
+ MethodFieldSize + SizeFieldSize +
+ HashFieldSize;
+ static inline const llvm::StringRef MagicNumber = "CCOB";
+ static inline const uint16_t Version = 1;
+
+public:
+ static llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
+ compress(const llvm::MemoryBuffer &Input, bool Verbose = false);
+ static llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
+ decompress(const llvm::MemoryBuffer &Input, bool Verbose = false);
+};
+
} // namespace clang
#endif // LLVM_CLANG_DRIVER_OFFLOADBUNDLER_H
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 0f93479170d73bc..b8295fa47327157 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1183,6 +1183,10 @@ def fgpu_inline_threshold_EQ : Joined<["-"], "fgpu-inline-threshold=">,
def fgpu_sanitize : Flag<["-"], "fgpu-sanitize">, Group<f_Group>,
HelpText<"Enable sanitizer for supported offloading devices">;
def fno_gpu_sanitize : Flag<["-"], "fno-gpu-sanitize">, Group<f_Group>;
+
+def foffload_compress : Flag<["-"], "foffload-compress">,
+ HelpText<"Compress offload device binaries (HIP only)">;
+def fno_offload_compress : Flag<["-"], "fno-offload-compress">;
}
// CUDA options
diff --git a/clang/lib/Driver/OffloadBundler.cpp b/clang/lib/Driver/OffloadBundler.cpp
index d11c41605bf39ee..7737c71485f5bf3 100644
--- a/clang/lib/Driver/OffloadBundler.cpp
+++ b/clang/lib/Driver/OffloadBundler.cpp
@@ -21,6 +21,7 @@
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Object/Archive.h"
@@ -28,17 +29,20 @@
#include "llvm/Object/Binary.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/Casting.h"
+#include "llvm/Support/Compression.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/EndianStream.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorOr.h"
#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MD5.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/Program.h"
#include "llvm/Support/Signals.h"
#include "llvm/Support/StringSaver.h"
+#include "llvm/Support/Timer.h"
#include "llvm/Support/WithColor.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TargetParser/Host.h"
@@ -48,6 +52,7 @@
#include <cstddef>
#include <cstdint>
#include <forward_list>
+#include <llvm/Support/Process.h>
#include <memory>
#include <set>
#include <string>
@@ -58,6 +63,10 @@ using namespace llvm;
using namespace llvm::object;
using namespace clang;
+static llvm::TimerGroup
+ ClangOffloadBundlerTimerGroup("Clang Offload Bundler Timer Group",
+ "Timer group for clang offload bundler");
+
/// Magic string that marks the existence of offloading data.
#define OFFLOAD_BUNDLER_MAGIC_STR "__CLANG_OFFLOAD_BUNDLE__"
@@ -224,20 +233,22 @@ class FileHandler {
/// Write the header of the bundled file to \a OS based on the information
/// gathered from \a Inputs.
- virtual Error WriteHeader(raw_fd_ostream &OS,
+ virtual Error WriteHeader(raw_ostream &OS,
ArrayRef<std::unique_ptr<MemoryBuffer>> Inputs) = 0;
/// Write the marker that initiates a bundle for the triple \a TargetTriple to
/// \a OS.
- virtual Error WriteBundleStart(raw_fd_ostream &OS,
- StringRef TargetTriple) = 0;
+ virtual Error WriteBundleStart(raw_ostream &OS, StringRef TargetTriple) = 0;
/// Write the marker that closes a bundle for the triple \a TargetTriple to \a
/// OS.
- virtual Error WriteBundleEnd(raw_fd_ostream &OS, StringRef TargetTriple) = 0;
+ virtual Error WriteBundleEnd(raw_ostream &OS, StringRef TargetTriple) = 0;
/// Write the bundle from \a Input into \a OS.
- virtual Error WriteBundle(raw_fd_ostream &OS, MemoryBuffer &Input) = 0;
+ virtual Error WriteBundle(raw_ostream &OS, MemoryBuffer &Input) = 0;
+
+ /// Finalize output file.
+ virtual Error finalizeOutputFile() { return Error::success(); }
/// List bundle IDs in \a Input.
virtual Error listBundleIDs(MemoryBuffer &Input) {
@@ -311,7 +322,7 @@ static uint64_t Read8byteIntegerFromBuffer(StringRef Buffer, size_t pos) {
}
/// Write 8-byte integers to a buffer in little-endian format.
-static void Write8byteIntegerToBuffer(raw_fd_ostream &OS, uint64_t Val) {
+static void Write8byteIntegerToBuffer(raw_ostream &OS, uint64_t Val) {
llvm::support::endian::write(OS, Val, llvm::support::little);
}
@@ -435,7 +446,7 @@ class BinaryFileHandler final : public FileHandler {
return Error::success();
}
- Error WriteHeader(raw_fd_ostream &OS,
+ Error WriteHeader(raw_ostream &OS,
ArrayRef<std::unique_ptr<MemoryBuffer>> Inputs) final {
// Compute size of the header.
@@ -472,19 +483,27 @@ class BinaryFileHandler final : public FileHandler {
return Error::success();
}
- Error WriteBundleStart(raw_fd_ostream &OS, StringRef TargetTriple) final {
+ Error WriteBundleStart(raw_ostream &OS, StringRef TargetTriple) final {
CurWriteBundleTarget = TargetTriple.str();
return Error::success();
}
- Error WriteBundleEnd(raw_fd_ostream &OS, StringRef TargetTriple) final {
+ Error WriteBundleEnd(raw_ostream &OS, StringRef TargetTriple) final {
return Error::success();
}
- Error WriteBundle(raw_fd_ostream &OS, MemoryBuffer &Input) final {
+ Error WriteBundle(raw_ostream &OS, MemoryBuffer &Input) final {
auto BI = BundlesInfo[CurWriteBundleTarget];
- OS.seek(BI.Offset);
+
+ // Pad with 0 to reach specified offset.
+ size_t CurrentPos = OS.tell();
+ size_t PaddingSize = BI.Offset > CurrentPos ? BI.Offset - CurrentPos : 0;
+ for (size_t I = 0; I < PaddingSize; ++I)
+ OS.write('\0');
+ assert(OS.tell() == BI.Offset);
+
OS.write(Input.getBufferStart(), Input.getBufferSize());
+
return Error::success();
}
};
@@ -607,7 +626,7 @@ class ObjectFileHandler final : public FileHandler {
return Error::success();
}
- Error WriteHeader(raw_fd_ostream &OS,
+ Error WriteHeader(raw_ostream &OS,
ArrayRef<std::unique_ptr<MemoryBuffer>> Inputs) final {
assert(BundlerConfig.HostInputIndex != ~0u &&
"Host input index not defined.");
@@ -617,12 +636,16 @@ class ObjectFileHandler final : public FileHandler {
return Error::success();
}
- Error WriteBundleStart(raw_fd_ostream &OS, StringRef TargetTriple) final {
+ Error WriteBundleStart(raw_ostream &OS, StringRef TargetTriple) final {
++NumberOfProcessedInputs;
return Error::success();
}
- Error WriteBundleEnd(raw_fd_ostream &OS, StringRef TargetTriple) final {
+ Error WriteBundleEnd(raw_ostream &OS, StringRef TargetTriple) final {
+ return Error::success();
+ }
+
+ Error finalizeOutputFile() final {
assert(NumberOfProcessedInputs <= NumberOfInputs &&
"Processing more inputs that actually exist!");
assert(BundlerConfig.HostInputIndex != ~0u &&
@@ -640,10 +663,6 @@ class ObjectFileHandler final : public FileHandler {
assert(BundlerConfig.ObjcopyPath != "" &&
"llvm-objcopy path not specified");
- // We write to the output file directly. So, we close it and use the name
- // to pass down to llvm-objcopy.
- OS.close();
-
// Temporary files that need to be removed.
TempFileHandlerRAII TempFiles;
@@ -684,7 +703,7 @@ class ObjectFileHandler final : public FileHandler {
return Error::success();
}
- Error WriteBundle(raw_fd_ostream &OS, MemoryBuffer &Input) final {
+ Error WriteBundle(raw_ostream &OS, MemoryBuffer &Input) final {
return Error::success();
}
@@ -781,22 +800,22 @@ class TextFileHandler final : public FileHandler {
return Error::success();
}
- Error WriteHeader(raw_fd_ostream &OS,
+ Error WriteHeader(raw_ostream &OS,
ArrayRef<std::unique_ptr<MemoryBuffer>> Inputs) final {
return Error::success();
}
- Error WriteBundleStart(raw_fd_ostream &OS, StringRef TargetTriple) final {
+ Error WriteBundleStart(raw_ostream &OS, StringRef TargetTriple) final {
OS << BundleStartString << TargetTriple << "\n";
return Error::success();
}
- Error WriteBundleEnd(raw_fd_ostream &OS, StringRef TargetTriple) final {
+ Error WriteBundleEnd(raw_ostream &OS, StringRef TargetTriple) final {
OS << BundleEndString << TargetTriple << "\n";
return Error::success();
}
- Error WriteBundle(raw_fd_ostream &OS, MemoryBuffer &Input) final {
+ Error WriteBundle(raw_ostream &OS, MemoryBuffer &Input) final {
OS << Input.getBuffer();
return Error::success();
}
@@ -881,6 +900,184 @@ CreateFileHandler(MemoryBuffer &FirstInput,
"'" + FilesType + "': invalid file type specified");
}
+OffloadBundlerConfig::OffloadBundlerConfig() {
+ auto IgnoreEnvVarOpt =
+ llvm::sys::Process::GetEnv("OFFLOAD_BUNDLER_IGNORE_ENV_VAR");
+ if (IgnoreEnvVarOpt.has_value() && IgnoreEnvVarOpt.value() == "1")
+ return;
+
+ auto VerboseEnvVarOpt = llvm::sys::Process::GetEnv("OFFLOAD_BUNDLER_VERBOSE");
+ if (VerboseEnvVarOpt.has_value())
+ Verbose = VerboseEnvVarOpt.value() == "1";
+
+ auto CompressEnvVarOpt =
+ llvm::sys::Process::GetEnv("OFFLOAD_BUNDLER_COMPRESS");
+ if (CompressEnvVarOpt.has_value())
+ Compress = CompressEnvVarOpt.value() == "1";
+}
+
+llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
+CompressedOffloadBundle::compress(const llvm::MemoryBuffer &Input,
+ bool Verbose) {
+ llvm::Timer HashTimer("Hash Calculation Timer", "Hash calculation time",
+ ClangOffloadBundlerTimerGroup);
+ if (Verbose)
+ HashTimer.startTimer();
+ llvm::MD5 Hash;
+ llvm::MD5::MD5Result Result;
+ Hash.update(Input.getBuffer());
+ Hash.final(Result);
+ uint64_t TruncatedHash = Result.low();
+ if (Verbose)
+ HashTimer.stopTimer();
+
+ SmallVector<uint8_t, 0> CompressedBuffer;
+ auto BufferUint8 = llvm::ArrayRef<uint8_t>(
+ reinterpret_cast<const uint8_t *>(Input.getBuffer().data()),
+ Input.getBuffer().size());
+
+ llvm::compression::Format CompressionFormat;
+
+ if (llvm::compression::zstd::isAvailable())
+ CompressionFormat = llvm::compression::Format::Zstd;
+ else if (llvm::compression::zlib::isAvailable())
+ CompressionFormat = llvm::compression::Format::Zlib;
+ else
+ return createStringError(llvm::inconvertibleErrorCode(),
+ "Compression not supported");
+
+ llvm::Timer CompressTimer("Compression Timer", "Compression time",
+ ClangOffloadBundlerTimerGroup);
+ if (Verbose)
+ CompressTimer.startTimer();
+ llvm::compression::compress(CompressionFormat, BufferUint8, CompressedBuffer);
+ if (Verbose)
+ CompressTimer.stopTimer();
+
+ uint16_t CompressionMethod = static_cast<uint16_t>(CompressionFormat);
+ uint32_t UncompressedSize = Input.getBuffer().size();
+
+ SmallVector<char, 0> FinalBuffer;
+ FinalBuffer.append(MagicNumber.begin(), MagicNumber.end());
+ FinalBuffer.append(reinterpret_cast<const char *>(&Version),
+ reinterpret_cast<const char *>(&Version) +
+ sizeof(Version));
+ FinalBuffer.append(reinterpret_cast<char *>(&CompressionMethod),
+ reinterpret_cast<char *>(&CompressionMethod) +
+ sizeof(CompressionMethod));
+ FinalBuffer.append(reinterpret_cast<char *>(&UncompressedSize),
+ reinterpret_cast<char *>(&UncompressedSize) +
+ sizeof(UncompressedSize));
+ FinalBuffer.append(reinterpret_cast<char *>(&TruncatedHash),
+ reinterpret_cast<char *>(&TruncatedHash) +
+ sizeof(TruncatedHash));
+ FinalBuffer.append(CompressedBuffer.begin(), CompressedBuffer.end());
+
+ if (Verbose) {
+ auto MethodUsed =
+ CompressionFormat == llvm::compression::Format::Zstd ? "zstd" : "zlib";
+ llvm::errs() << "Compressed bundle format version: " << Version << "\n"
+ << "Compression method used: " << MethodUsed << "\n"
+ << "Binary size before compression: " << UncompressedSize
+ << " bytes\n"
+ << "Binary size after compression: " << CompressedBuffer.size()
+ << " bytes\n"
+ << "Truncated MD5 hash: "
+ << llvm::format_hex(TruncatedHash, 16) << "\n";
+ }
+
+ return llvm::MemoryBuffer::getMemBufferCopy(
+ llvm::StringRef(FinalBuffer.data(), FinalBuffer.size()));
+}
+
+llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
+CompressedOffloadBundle::decompress(const llvm::MemoryBuffer &Input,
+ bool Verbose) {
+
+ StringRef Blob = Input.getBuffer();
+
+ if (Blob.size() < HeaderSize) {
+ return llvm::MemoryBuffer::getMemBufferCopy(Blob);
+ }
+ StringRef Magic = Blob.substr(0, MagicSize);
+ if (Magic != MagicNumber) {
+ if (Verbose)
+ llvm::errs() << "Uncompressed bundle.\n";
+ return llvm::MemoryBuffer::getMemBufferCopy(Blob);
+ }
+
+ uint16_t ThisVersion = *reinterpret_cast<const uint16_t *>(
+ Input.getBuffer().data() + MagicNumber.size());
+ uint16_t CompressionMethod = *reinterpret_cast<const uint16_t *>(
+ Blob.data() + MagicSize + VersionFieldSize);
+ uint32_t UncompressedSize = *reinterpret_cast<const uint32_t *>(
+ Blob.data() + MagicSize + VersionFieldSize + MethodFieldSize);
+ uint64_t StoredHash = *reinterpret_cast<const uint64_t *>(
+ Blob.data() + MagicSize + VersionFieldSize + MethodFieldSize +
+ SizeFieldSize);
+
+ llvm::compression::Format CompressionFormat;
+ if (CompressionMethod ==
+ static_cast<uint16_t>(llvm::compression::Format::Zlib))
+ CompressionFormat = llvm::compression::Format::Zlib;
+ else if (CompressionMethod ==
+ static_cast<uint16_t>(llvm::compression::Format::Zstd))
+ CompressionFormat = llvm::compression::Format::Zstd;
+ else
+ return createStringError(inconvertibleErrorCode(),
+ "Unknown compressing method");
+
+ llvm::Timer DecompressTimer("Decompression Timer", "Decompression time",
+ ClangOffloadBundlerTimerGroup);
+ if (Verbose)
+ DecompressTimer.startTimer();
+
+ SmallVector<uint8_t, 0> DecompressedData;
+ StringRef CompressedData = Blob.substr(HeaderSize);
+ if (llvm::Error DecompressionError = llvm::compression::decompress(
+ CompressionFormat, llvm::arrayRefFromStringRef(CompressedData),
+ DecompressedData, UncompressedSize))
+ return createStringError(inconvertibleErrorCode(),
+ "Could not decompress embedded file contents: " +
+ llvm::toString(std::move(DecompressionError)));
+
+ if (Verbose) {
+ DecompressTimer.stopTimer();
+
+ // Recalculate MD5 hash
+ llvm::Timer HashRecalcTimer("Hash Recalculation Timer",
+ "Hash recalculation time",
+ ClangOffloadBundlerTimerGroup);
+ HashRecalcTimer.startTimer();
+ llvm::MD5 Hash;
+ llvm::MD5::MD5Result Result;
+ Hash.update(llvm::ArrayRef<uint8_t>(DecompressedData.data(),
+ DecompressedData.size()));
+ Hash.final(Result);
+ uint64_t RecalculatedHash = Result.low();
+ HashRecalcTimer.stopTimer();
+ bool HashMatch = (StoredHash == RecalculatedHash);
+
+ llvm::errs() << "Compressed bundle format version: " << ThisVersion << "\n"
+ << "Decompression method: "
+ << (CompressionFormat == llvm::compression::Format::Zlib
+ ? "zlib"
+ : "zstd")
+ << "\n"
+ << "Size before decompression: " << CompressedData.size()
+ << " bytes\n"
+ << "Size after decompression: " << UncompressedSize
+ << " bytes\n"
+ << "Stored hash: " << llvm::format_hex(StoredHash, 16) << "\n"
+ << "Recalculated hash: "
+ << llvm::format_hex(RecalculatedHash, 16) << "\n"
+ << "Hashes match: " << (HashMatch ? "Yes" : "No") << "\n";
+ }
+
+ return llvm::MemoryBuffer::getMemBufferCopy(
+ llvm::toStringRef(DecompressedData));
+}
+
// List bundle IDs. Return true if an error was found.
Error OffloadBundler::ListBundleIDsInFile(
StringRef InputFileName, const OffloadBundlerConfig &BundlerConfig) {
@@ -890,28 +1087,35 @@ Error OffloadBundler::ListBundleIDsInFile(
if (std::error_cod...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/67162
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