pkgsrc/lang/llvm/DESCR
tnn b861e8f85b Update to clang-3.8.0. Split out llvm tools to lang/llvm.
Packaged in pkgsrc-wip by myself and Kamil.
Remove stale pkgsrc/SunOS bread crumbs that were difficult to merge
following the build framework switch. Needs to be redone. (Sorry!)

Summary of significant changes in LLVM:
- switch build framework from autoconf to CMake
- llvm-ar now supports thin archives.
- llvm doesn t produce .data.rel.ro.local or .data.rel sections anymore.
- opional support for linking clang and the LLVM tools with a single
  libLLVM shared library

  pkgsrc note: we have this library in lang/libLLVM, but we don't currently
  use it. We may do so in the future if/when the API matures.

- The optimization to move the prologue and epilogue of functions in colder
  code path (shrink-wrapping) is now enabled by default
- new target-independent gcc-compatible emulated Thread Local Storage mode
- various target specific optimizations

Summary of significant changes in Clang:

- new compiler flags for tuning what DWARF information is included
- better strict alignment handling
- better support for __builtin_object_size
2016-03-10 15:01:52 +00:00

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Low Level Virtual Machine (LLVM) is:
A compilation strategy designed to enable effective program optimization across
the entire lifetime of a program. LLVM supports effective optimization at
compile time, link-time (particularly interprocedural), run-time and offline
(i.e., after software is installed), while remaining transparent to developers
and maintaining compatibility with existing build scripts.
A virtual instruction set - LLVM is a low-level object code representation that
uses simple RISC-like instructions, but provides rich, language-independent,
type information and dataflow (SSA) information about operands. This combination
enables sophisticated transformations on object code, while remaining
light-weight enough to be attached to the executable. This combination is key to
allowing link-time, run-time, and offline transformations.
A compiler infrastructure - LLVM is also a collection of source code that
implements the language and compilation strategy. The primary components of the
LLVM infrastructure are a GCC-based C & C++ front-end, a link-time optimization
framework with a growing set of global and interprocedural analyses and
transformations, static back-ends for the X86, X86-64, PowerPC 32/64, ARM,
Thumb, IA-64, Alpha and SPARC architectures, a back-end which emits portable C
code, and a Just-In-Time compiler for X86, X86-64, PowerPC 32/64 processors.