[llvm-commits] [llvm] r115728 - in /llvm/trunk: include/llvm/Bitcode/ReaderWriter.h lib/Bitcode/Reader/BitcodeReader.cpp lib/Bitcode/Reader/BitcodeReader.h tools/lto/LTOModule.cpp
Nick Lewycky
nicholas at mxc.ca
Wed Oct 6 00:16:53 PDT 2010
Bill Wendling wrote:
> Author: void
> Date: Tue Oct 5 20:22:42 2010
> New Revision: 115728
>
> URL: http://llvm.org/viewvc/llvm-project?rev=115728&view=rev
> Log:
> Provide a fast "get me the target triple from the module" API. This can
> drastically reduce the linking time during LTO.
>
> Patch by Shantonu Sen!
>
> Modified:
> llvm/trunk/include/llvm/Bitcode/ReaderWriter.h
> llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp
> llvm/trunk/lib/Bitcode/Reader/BitcodeReader.h
> llvm/trunk/tools/lto/LTOModule.cpp
>
> Modified: llvm/trunk/include/llvm/Bitcode/ReaderWriter.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Bitcode/ReaderWriter.h?rev=115728&r1=115727&r2=115728&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/Bitcode/ReaderWriter.h (original)
> +++ llvm/trunk/include/llvm/Bitcode/ReaderWriter.h Tue Oct 5 20:22:42 2010
> @@ -33,6 +33,15 @@
> LLVMContext& Context,
> std::string *ErrMsg = 0);
>
> + /// getBitcodeTargetTriple - Read the header of the specified bitcode
> + /// buffer and extract just the triple information. If successful,
> + /// this returns a string and *does not* take ownership
> + /// of 'buffer'. On error, this returns "", and fills in *ErrMsg
> + /// if ErrMsg is non-null.
> + std::string getBitcodeTargetTriple(MemoryBuffer *Buffer,
> + LLVMContext& Context,
> + std::string *ErrMsg = 0);
Tabs!
Nick
> +
> /// ParseBitcodeFile - Read the specified bitcode file, returning the module.
> /// If an error occurs, this returns null and fills in *ErrMsg if it is
> /// non-null. This method *never* takes ownership of Buffer.
>
> Modified: llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp?rev=115728&r1=115727&r2=115728&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp (original)
> +++ llvm/trunk/lib/Bitcode/Reader/BitcodeReader.cpp Tue Oct 5 20:22:42 2010
> @@ -1600,6 +1600,112 @@
> return false;
> }
>
> +bool BitcodeReader::ParseModuleTriple(std::string&Triple) {
> + if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
> + return Error("Malformed block record");
> +
> + SmallVector<uint64_t, 64> Record;
> +
> + // Read all the records for this module.
> + while (!Stream.AtEndOfStream()) {
> + unsigned Code = Stream.ReadCode();
> + if (Code == bitc::END_BLOCK) {
> + if (Stream.ReadBlockEnd())
> + return Error("Error at end of module block");
> +
> + return false;
> + }
> +
> + if (Code == bitc::ENTER_SUBBLOCK) {
> + switch (Stream.ReadSubBlockID()) {
> + default: // Skip unknown content.
> + if (Stream.SkipBlock())
> + return Error("Malformed block record");
> + break;
> + }
> + continue;
> + }
> +
> + if (Code == bitc::DEFINE_ABBREV) {
> + Stream.ReadAbbrevRecord();
> + continue;
> + }
> +
> + // Read a record.
> + switch (Stream.ReadRecord(Code, Record)) {
> + default: break; // Default behavior, ignore unknown content.
> + case bitc::MODULE_CODE_VERSION: // VERSION: [version#]
> + if (Record.size()< 1)
> + return Error("Malformed MODULE_CODE_VERSION");
> + // Only version #0 is supported so far.
> + if (Record[0] != 0)
> + return Error("Unknown bitstream version!");
> + break;
> + case bitc::MODULE_CODE_TRIPLE: { // TRIPLE: [strchr x N]
> + std::string S;
> + if (ConvertToString(Record, 0, S))
> + return Error("Invalid MODULE_CODE_TRIPLE record");
> + Triple = S;
> + break;
> + }
> + }
> + Record.clear();
> + }
> +
> + return Error("Premature end of bitstream");
> +}
> +
> +bool BitcodeReader::ParseTriple(std::string&Triple) {
> + if (Buffer->getBufferSize()& 3)
> + return Error("Bitcode stream should be a multiple of 4 bytes in length");
> +
> + unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
> + unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
> +
> + // If we have a wrapper header, parse it and ignore the non-bc file contents.
> + // The magic number is 0x0B17C0DE stored in little endian.
> + if (isBitcodeWrapper(BufPtr, BufEnd))
> + if (SkipBitcodeWrapperHeader(BufPtr, BufEnd))
> + return Error("Invalid bitcode wrapper header");
> +
> + StreamFile.init(BufPtr, BufEnd);
> + Stream.init(StreamFile);
> +
> + // Sniff for the signature.
> + if (Stream.Read(8) != 'B' ||
> + Stream.Read(8) != 'C' ||
> + Stream.Read(4) != 0x0 ||
> + Stream.Read(4) != 0xC ||
> + Stream.Read(4) != 0xE ||
> + Stream.Read(4) != 0xD)
> + return Error("Invalid bitcode signature");
> +
> + // We expect a number of well-defined blocks, though we don't necessarily
> + // need to understand them all.
> + while (!Stream.AtEndOfStream()) {
> + unsigned Code = Stream.ReadCode();
> +
> + if (Code != bitc::ENTER_SUBBLOCK)
> + return Error("Invalid record at top-level");
> +
> + unsigned BlockID = Stream.ReadSubBlockID();
> +
> + // We only know the MODULE subblock ID.
> + switch (BlockID) {
> + case bitc::MODULE_BLOCK_ID:
> + if (ParseModuleTriple(Triple))
> + return true;
> + break;
> + default:
> + if (Stream.SkipBlock())
> + return Error("Malformed block record");
> + break;
> + }
> + }
> +
> + return false;
> +}
> +
> /// ParseMetadataAttachment - Parse metadata attachments.
> bool BitcodeReader::ParseMetadataAttachment() {
> if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
> @@ -2537,7 +2643,24 @@
> // Read in the entire module, and destroy the BitcodeReader.
> if (M->MaterializeAllPermanently(ErrMsg)) {
> delete M;
> - return NULL;
> + return 0;
> }
> +
> return M;
> }
> +
> +std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
> + LLVMContext& Context,
> + std::string *ErrMsg) {
> + BitcodeReader *R = new BitcodeReader(Buffer, Context);
> + // Don't let the BitcodeReader dtor delete 'Buffer'.
> + R->setBufferOwned(false);
> +
> + std::string Triple("");
> + if (R->ParseTriple(Triple))
> + if (ErrMsg)
> + *ErrMsg = R->getErrorString();
> +
> + delete R;
> + return Triple;
> +}
>
> Modified: llvm/trunk/lib/Bitcode/Reader/BitcodeReader.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Reader/BitcodeReader.h?rev=115728&r1=115727&r2=115728&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Bitcode/Reader/BitcodeReader.h (original)
> +++ llvm/trunk/lib/Bitcode/Reader/BitcodeReader.h Tue Oct 5 20:22:42 2010
> @@ -212,6 +212,10 @@
> /// @brief Main interface to parsing a bitcode buffer.
> /// @returns true if an error occurred.
> bool ParseBitcodeInto(Module *M);
> +
> + /// @brief Cheap mechanism to just extract module triple
> + /// @returns true if an error occurred.
> + bool ParseTriple(std::string&Triple);
> private:
> const Type *getTypeByID(unsigned ID, bool isTypeTable = false);
> Value *getFnValueByID(unsigned ID, const Type *Ty) {
> @@ -270,6 +274,7 @@
> bool ResolveGlobalAndAliasInits();
> bool ParseMetadata();
> bool ParseMetadataAttachment();
> + bool ParseModuleTriple(std::string&Triple);
> };
>
> } // End llvm namespace
>
> Modified: llvm/trunk/tools/lto/LTOModule.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/lto/LTOModule.cpp?rev=115728&r1=115727&r2=115728&view=diff
> ==============================================================================
> --- llvm/trunk/tools/lto/LTOModule.cpp (original)
> +++ llvm/trunk/tools/lto/LTOModule.cpp Tue Oct 5 20:22:42 2010
> @@ -64,15 +64,10 @@
>
> // Takes ownership of buffer.
> bool LTOModule::isTargetMatch(MemoryBuffer *buffer, const char *triplePrefix) {
> - OwningPtr<Module> m(getLazyBitcodeModule(buffer, getGlobalContext()));
> - // On success, m owns buffer and both are deleted at end of this method.
> - if (!m) {
> - delete buffer;
> - return false;
> - }
> - std::string actualTarget = m->getTargetTriple();
> - return (strncmp(actualTarget.c_str(), triplePrefix,
> - strlen(triplePrefix)) == 0);
> + std::string Triple = getBitcodeTargetTriple(buffer, getGlobalContext());
> + delete buffer;
> + return (strncmp(Triple.c_str(), triplePrefix,
> + strlen(triplePrefix)) == 0);
> }
>
>
>
>
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