[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
Bill Wendling
isanbard at gmail.com
Tue Oct 5 18:22:43 PDT 2010
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);
+
/// 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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