[clang] [HIP] Support compressing device binary (PR #67162)

[Joseph Huber via cfe-commits]

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@@ -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;
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jhuber6 wrote:

Wouldn't this be easier with a `raw_svector_ostream`?

https://github.com/llvm/llvm-project/pull/67162