llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-21 16:31:16 +00:00

History

Cameron Zwarich 8d7285d0e5 The signed version of our "magic number" computation for the integer approximation of a constant had a minor typo introduced when copying it from the book, which caused it to favor negative approximations over positive approximations in many cases. Positive approximations require fewer operations beyond the multiplication. In the case of division by 3, we still generate code that is a single instruction larger than GCC's code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126097 91177308-0d34-0410-b5e6-96231b3b80d8		2011-02-21 00:22:02 +00:00
..
Unix	improve support for OpenBSD, patch by Amit Kulkarni!	2011-02-18 17:04:56 +00:00
Windows	Windows/Windows.h: Redefine _WIN32_WINNT here. mingw-w64 tends to define it as 0x0502 in its headers.	2011-02-09 04:18:30 +00:00
Allocator.cpp
APFloat.cpp	Enhance constant folding of bitcast operations on vectors of floats.	2011-02-17 21:22:27 +00:00
APInt.cpp	The signed version of our "magic number" computation for the integer approximation	2011-02-21 00:22:02 +00:00
APSInt.cpp
Atomic.cpp
circular_raw_ostream.cpp
CMakeLists.txt	Add ADT/IntEqClasses.h as a light-weight implementation of EquivalenceClasses.h.	2010-12-21 00:04:46 +00:00
CommandLine.cpp	Support/CommandLine: Fix LookupNearestOption to also search extra option names.	2011-01-24 17:27:17 +00:00
ConstantRange.cpp
COPYRIGHT.regex
CrashRecoveryContext.cpp
DAGDeltaAlgorithm.cpp
Debug.cpp
DeltaAlgorithm.cpp
Disassembler.cpp
Dwarf.cpp	Provide tag strings for llvm specific tags.	2011-02-18 23:06:29 +00:00
DynamicLibrary.cpp
Errno.cpp	lib/Support/Errno.cpp: Check strerror_s() with HAVE_DECL_STRERROR_S in config.h.*.	2011-02-09 04:18:48 +00:00
ErrorHandling.cpp
FileUtilities.cpp	MemoryBuffer now return an error_code and returns a OwningPtr<MemoryBuffer> via an out parm.	2010-12-16 03:29:14 +00:00
FoldingSet.cpp
FormattedStream.cpp	Add missing standard headers. Patch by Joerg Sonnenberger!	2010-12-19 20:43:38 +00:00
GraphWriter.cpp
Host.cpp
IncludeFile.cpp
IntEqClasses.cpp	Use IntEqClasses to compute connected components of live intervals.	2010-12-21 00:48:17 +00:00
IntervalMap.cpp
IsInf.cpp
IsNAN.cpp
Makefile
ManagedStatic.cpp
Memory.cpp
MemoryBuffer.cpp	Don't open the file again in the gold plugin. To be able to do this, update	2011-02-08 22:40:47 +00:00
MemoryObject.cpp
Mutex.cpp	Check the errorcode.	2011-02-18 00:47:07 +00:00
Path.cpp	Support/PathV2: Add identify_magic.	2011-01-15 20:39:36 +00:00
PathV2.cpp	Implement a function from PathV2 whose definition is missing.	2011-02-15 17:51:19 +00:00
PluginLoader.cpp
PrettyStackTrace.cpp	Change all self assignments X=X to (void)X, so that we can turn on a	2010-12-23 00:58:24 +00:00
Process.cpp
Program.cpp
raw_os_ostream.cpp
raw_ostream.cpp	raw_fd_ostream: Add a SetUseAtomicWrites() method (uses writev).	2011-02-03 03:32:32 +00:00
README.txt.system
regcclass.h
regcname.h
regcomp.c
regengine.inc
regerror.c
regex2.h
regex_impl.h
Regex.cpp
regexec.c
regfree.c
regstrlcpy.c
regutils.h
RWMutex.cpp
SearchForAddressOfSpecialSymbol.cpp
Signals.cpp
SmallPtrSet.cpp
SmallVector.cpp
SourceMgr.cpp	MemoryBuffer now return an error_code and returns a OwningPtr<MemoryBuffer> via an out parm.	2010-12-16 03:29:14 +00:00
Statistic.cpp
StringExtras.cpp
StringMap.cpp	Change all self assignments X=X to (void)X, so that we can turn on a	2010-12-23 00:58:24 +00:00
StringPool.cpp
StringRef.cpp
system_error.cpp
SystemUtils.cpp
TargetRegistry.cpp
Threading.cpp
ThreadLocal.cpp
Timer.cpp
TimeValue.cpp
ToolOutputFile.cpp
Triple.cpp	Triple::MinGW64 is deprecated and removed. We can use Triple::MinGW32 generally.	2011-02-17 12:24:17 +00:00
Twine.cpp
Valgrind.cpp

README.txt.system

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