add README.md

I took the information from the old website, merged it with INSTALL and
converted it to a markdown-compatible readme that can be rendered by
github.

This replaces INSTALL.

Author: vks

INSTALL

@@ -1,27 +1 @@
-Build Requirements
-==================
-
-cmake >= 2.8.3
-
-C++11 Compiler:
- * GCC >= 4.6
- * clang >= 3.2
- * ICC >= 13
- * Visual Studio >= 2012
-
-Building and Installing Vc
-==========================
-
-* Create a build directory:
-
-$ mkdir build
-$ cd build
-
-* Call cmake with the relevant options:
-
-$ cmake -DCMAKE_INSTALL_PREFIX=/opt/Vc -DBUILD_TESTING=OFF <srcdir>
-
-* Build and install:
-
-$ make -j16
-$ make install
+See README.md.

README.md

@@ -0,0 +1,86 @@
+# Vc: portable, zero-overhead SIMD library for C++
+
+The use of SIMD is becoming increasingly important with modern CPUs. The SIMD
+instruction sets are being improved: new instructions are added as well as
+performance improvements relative to the scalar instructions. The next
+generations of CPUs will double the vector width. Neglecting SIMD in
+high-performance code thus becomes more expensive, compared to the theoretical
+performance of CPUs.
+
+The use of SIMD instructions is not easy. C/C++ compilers support some
+extensions to ease development for SSE and AVX. Commonly intrinsics are the
+available extension of choice. Intrinsics basically map every SIMD instruction
+to a C function. The use of these intrinsics leads to code which is hard to read
+and maintain in addition to making portability to other vector units
+complicated.
+
+Vc is a free software library to ease explicit vectorization of C++ code. It has
+an intuitive API and provides portability between different compilers and
+compiler versions as well as portability between different vector instruction
+sets. Thus an application written with Vc can be compiled for
+
+* AVX
+* SSE2 up to SSE4.2 or SSE4a
+* Scalar (fallback which works everywhere)
+* MIC (for Vc 1.0)
+* NEON (in development)
+
+
+## Build Requirements
+
+cmake >= 2.8.3
+
+C++11 Compiler:
+
+* GCC >= 4.6
+* clang >= 3.2
+* ICC >= 13
+* Visual Studio >= 2012
+
+
+## Building and Installing Vc
+
+* Create a build directory:
+
+```sh
+$ mkdir build
+$ cd build
+```
+
+* Call cmake with the relevant options:
+
+```sh
+$ cmake -DCMAKE_INSTALL_PREFIX=/opt/Vc -DBUILD_TESTING=OFF <srcdir>
+```
+
+* Build and install:
+
+```sh
+$ make -j16
+$ make install
+```
+
+
+## Publications
+
+* [M. Kretz and V. Lindenstruth, "Vc: A C++ library for explicit
+  vectorization", Software: Practice and Experience,
+  2011.](http://dx.doi.org/10.1002/spe.1149)
+* [M. Kretz, "Efficient Use of Multi- and Many-Core Systems with Vectorization
+  and Multithreading", University of Heidelberg,
+  2009.](http://code.compeng.uni-frankfurt.de/attachments/13/Diplomarbeit.pdf)
+
+
+## Communication
+
+A channel on the freenode IRC network is reserved for discussions on Vc:
+[##vc on freenode](irc://chat.freenode.net:6665/##vc)
+([via SSL](ircs://chat.freenode.net:7000/##vc))
+
+
+## License
+
+Vc is released under the LGPL 3. Since Vc is a template library this gives you
+a lot of freedom. For the details you can take a look at the [Licensing FAQ of
+Eigen](http://eigen.tuxfamily.org/index.php?title=Licensing_FAQ) which is a C++
+template library released under the LGPL 3 or GPL 2.