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mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-25 04:02:41 +01:00
llvm-mirror/lib/Support
Rui Ueyama 82b6d2e64d Support: Improve performance of FileOutputBuffer on Windows
We extend an underlying file before mmap'ing it, but it's not needed
on Windows. Extending file is slow on Windows, so we should avoid doing that.
The difference gets larger as the size of an output file gets larger.
It shove off 2 seconds out of 25 seconds when linking chrome.dll with LLD,
for example.

llvm-svn: 231452
2015-03-06 06:07:32 +00:00
..
Unix Replace PrintStackTrace(FILE*) with PrintStackTrace(raw_ostream&) 2015-03-05 19:10:52 +00:00
Windows Replace PrintStackTrace(FILE*) with PrintStackTrace(raw_ostream&) 2015-03-05 19:10:52 +00:00
Allocator.cpp
APFloat.cpp [APFloat][ADT] Fix sign handling logic for FMA results that truncate to zero. 2015-01-04 01:20:55 +00:00
APInt.cpp MathExtras: Bring Count(Trailing|Leading)Ones and CountPopulation in line with countTrailingZeros 2015-02-12 15:35:40 +00:00
APSInt.cpp
ARMBuildAttrs.cpp
ARMWinEH.cpp
Atomic.cpp
BlockFrequency.cpp
BranchProbability.cpp
circular_raw_ostream.cpp
CMakeLists.txt Use ADDITIONAL_HEADER_DIRS in all LLVM CMake projects. 2015-02-11 03:28:02 +00:00
CommandLine.cpp Prefer SmallVector::append/insert over push_back loops. 2015-02-17 15:29:18 +00:00
Compression.cpp [msan] Annotate zlib functions for MemorySanitizer. 2014-11-25 15:24:07 +00:00
ConvertUTF.c
ConvertUTFWrapper.cpp Make UTF8->UTF16 conversion null terminate output on empty input. 2015-02-08 18:08:51 +00:00
COPYRIGHT.regex
CrashRecoveryContext.cpp For CrashRecoveryContext::RunSafelyOnThread, propagate Darwin's PRIO_DARWIN_BG to the new thread if it is 2014-06-25 23:54:50 +00:00
DAGDeltaAlgorithm.cpp
DataExtractor.cpp
DataStream.cpp Merge StreamableMemoryObject into MemoryObject. 2014-11-12 03:55:46 +00:00
Debug.cpp Provide the same ABI regardless of NDEBUG 2015-02-19 05:30:16 +00:00
DeltaAlgorithm.cpp
Dwarf.cpp Support: Add dwarf::getOperationEncoding() 2015-02-13 01:05:00 +00:00
DynamicLibrary.cpp Revert "Limit the symbol search in DynamicLibrary to the module that was opened." 2014-08-27 17:51:43 +00:00
Errno.cpp Silence warning: variable 'buffer' set but not used. 2014-12-04 21:36:38 +00:00
ErrorHandling.cpp [cleanup] Re-sort all the #include lines in LLVM using 2015-01-14 11:23:27 +00:00
FileOutputBuffer.cpp Support: Improve performance of FileOutputBuffer on Windows 2015-03-06 06:07:32 +00:00
FileUtilities.cpp Remove some calls to std::move. 2014-08-01 14:31:55 +00:00
FoldingSet.cpp
FormattedStream.cpp
GraphWriter.cpp Fix style. 2014-11-07 21:30:36 +00:00
Hashing.cpp
Host.cpp We require MSVC 1800 as our minimum, so these checks can safely go away; NFC. 2015-02-16 18:23:00 +00:00
IntEqClasses.cpp
IntervalMap.cpp
IntrusiveRefCntPtr.cpp
IsInf.cpp
IsNAN.cpp
LEB128.cpp
LineIterator.cpp Add CRLF support to LineIterator. 2014-11-03 14:09:47 +00:00
LLVMBuild.txt
Locale.cpp
LockFileManager.cpp [Support] Increase timeout for the LockFileManager back to 5 mins. 2015-03-04 22:54:38 +00:00
Makefile
ManagedStatic.cpp Revert 220932. 2014-11-05 04:44:31 +00:00
MathExtras.cpp Fix llvm::huge_valf multiple initializations with Visual C++. 2014-09-27 14:41:29 +00:00
MD5.cpp Make the MD5 result name consistent between functions, header and source. 2014-10-06 13:48:07 +00:00
Memory.cpp
MemoryBuffer.cpp Pass EC by reference to MemoryBufferMMapFile to return error code. 2014-12-12 22:27:53 +00:00
MemoryObject.cpp Make readBytes pure virtual. Every real implementation has it. 2014-11-12 02:30:38 +00:00
Mutex.cpp
Options.cpp Defining a new API for debug options that doesn't rely on static global cl::opts. 2014-10-15 21:54:35 +00:00
Path.cpp Use read{16,32,64}{le,be}() instead of *reinterpret_cast<u{little,big}{16,32,64}_t>(). 2015-03-02 21:19:12 +00:00
PluginLoader.cpp
PrettyStackTrace.cpp Fix the preprocessor checks used to determine if backtraces have been enabled. 2015-01-29 07:53:13 +00:00
Process.cpp Remove dead code. NFC. 2014-12-04 16:59:36 +00:00
Program.cpp
RandomNumberGenerator.cpp Random Number Generator Refactoring (removing from Module) 2014-12-17 18:12:10 +00:00
raw_os_ostream.cpp
raw_ostream.cpp Format: Modernize using variadic templates. 2015-02-15 22:15:41 +00:00
README.txt.system
regcclass.h
regcname.h
regcomp.c Use wider type for overflow check on LLP64 platforms like Win64, found by clang-cl -Wtautological 2015-02-26 21:07:30 +00:00
regengine.inc
regerror.c
regex2.h
regex_impl.h
Regex.cpp
regexec.c
regfree.c
regstrlcpy.c
regutils.h
RWMutex.cpp
ScaledNumber.cpp [cleanup] Re-sort all the #include lines in LLVM using 2015-01-14 11:23:27 +00:00
SearchForAddressOfSpecialSymbol.cpp
Signals.cpp
SmallPtrSet.cpp Sync the __builtin_expects for our 3 quadratically probed hash table implementations. 2015-02-23 16:41:36 +00:00
SmallVector.cpp
SourceMgr.cpp Remove unnecessary .c_str() when implicitly converting to Twine 2014-11-06 01:13:27 +00:00
SpecialCaseList.cpp SpecialCaseList: Add support for parsing multiple input files. 2015-02-04 17:39:48 +00:00
Statistic.cpp
StreamingMemoryObject.cpp Removing LLVM_DELETED_FUNCTION, as MSVC 2012 was the last reason for requiring the macro. NFC; LLVM edition. 2015-02-15 22:54:22 +00:00
StringExtras.cpp
StringMap.cpp Sync the __builtin_expects for our 3 quadratically probed hash table implementations. 2015-02-23 16:41:36 +00:00
StringPool.cpp
StringRef.cpp Simplify creation of a bunch of ArrayRefs by using None, makeArrayRef or just letting them be implicitly created. 2014-08-27 05:25:25 +00:00
SystemUtils.cpp
TargetRegistry.cpp Remove obsolete function TargetRegistry::getClosestTargetForJIT() 2014-07-01 10:47:13 +00:00
Threading.cpp Revert 220932. 2014-11-05 04:44:31 +00:00
ThreadLocal.cpp ThreadLocal: Move Unix-specific code out of Support/ThreadLocal.cpp 2014-12-15 01:19:53 +00:00
Timer.cpp Modernize raw_fd_ostream's constructor a bit. 2014-08-25 18:16:47 +00:00
TimeValue.cpp Cleaning up static initializers in TimeValue. 2014-08-29 01:05:12 +00:00
ToolOutputFile.cpp Modernize raw_fd_ostream's constructor a bit. 2014-08-25 18:16:47 +00:00
Triple.cpp Make Triple::getOSVersion make sense for Android. 2015-03-03 18:23:51 +00:00
Twine.cpp
Unicode.cpp
Valgrind.cpp Provide the same ABI regardless of NDEBUG 2015-02-19 05:30:16 +00:00
Watchdog.cpp
YAMLParser.cpp Demote vectors to arrays. No functionality change. 2015-02-19 15:26:17 +00:00
YAMLTraits.cpp Detect malformed YAML sequence in yaml::Input::beginSequence() 2015-03-02 17:26:43 +00:00

Design Of lib/System
====================

The software in this directory is designed to completely shield LLVM from any
and all operating system specific functionality. It is not intended to be a
complete operating system wrapper (such as ACE), but only to provide the
functionality necessary to support LLVM.

The software located here, of necessity, has very specific and stringent design
rules. Violation of these rules means that cracks in the shield could form and
the primary goal of the library is defeated. By consistently using this library,
LLVM becomes more easily ported to new platforms since the only thing requiring
porting is this library.

Complete documentation for the library can be found in the file:
  llvm/docs/SystemLibrary.html
or at this URL:
  http://llvm.org/docs/SystemLibrary.html

While we recommend that you read the more detailed documentation, for the
impatient, here's a high level summary of the library's requirements.

 1. No system header files are to be exposed through the interface.
 2. Std C++ and Std C header files are okay to be exposed through the interface.
 3. No exposed system-specific functions.
 4. No exposed system-specific data.
 5. Data in lib/System classes must use only simple C++ intrinsic types.
 6. Errors are handled by returning "true" and setting an optional std::string
 7. Library must not throw any exceptions, period.
 8. Interface functions must not have throw() specifications.
 9. No duplicate function impementations are permitted within an operating
    system class.

To accomplish these requirements, the library has numerous design criteria that
must be satisfied. Here's a high level summary of the library's design criteria:

 1. No unused functionality (only what LLVM needs)
 2. High-Level Interfaces
 3. Use Opaque Classes
 4. Common Implementations
 5. Multiple Implementations
 6. Minimize Memory Allocation
 7. No Virtual Methods