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external/llvm/projects/llvm-cbe/README.md

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+llvm-cbe
+========
+
+resurrected LLVM "C Backend", with improvements
+
+
+INSTALLATION INSTRUCTIONS
+=========================
+
+This version of the LLVM-CBE library works with LLVM 6.0 and 7.0. You will have
+to compile this version of LLVM before you try to use LLVM-CBE. This
+guide will walk you through the compilation and installation of both
+tools and show usage statements to verify that the LLVM-CBE library is
+compiled correctly.
+
+The library is known to compile on various Linux versions (Redhat,
+Mageia, Ubuntu, Debian), Mac OS X, and Windows (Mingw-w64).
+
+Step 1: Installing LLVM
+=======================
+
+LLVM-CBE relies on specific LLVM internals, and so it is best to use
+it with a specific revision of the LLVM development tree. Currently,
+llvm-cbe works with the LLVM 6.0 and 7.0 release versions and autotools.
+
+Note: to convert C to LLVM IR to run the tests, you will also need a C compiler such as clang.
+
+The first step is to compile LLVM on your machine
+(this assumes an in-tree build, but out-of-tree will also work):
+
+     cd $HOME
+     git clone https://github.com/llvm-mirror/llvm
+     cd llvm
+     git checkout release_37
+     mkdir build
+     cd build
+     ../configure
+     make
+
+Step 2: Compiling LLVM-CBE
+==========================
+
+Next, download and compile llvm-cbe from the same folder:
+
+    cd $HOME/llvm/projects
+    git clone https://github.com/JuliaComputing/llvm-cbe
+    cd ../build
+    make
+
+Step 3: Usage Examples
+======================
+
+If llvm-cbe compiles, you should be able to run it with the following commands.
+```
+$ cd $HOME/llvm/projects/llvm-cbe/test/selectionsort
+$ ls
+main.c
+$ clang -S -emit-llvm main.c
+$ ls
+main.c main.ll
+$ $(HOME)/llvm/build/Debug+Asserts/bin/llvm-cbe main.ll
+```
+
+Compile Generated C-Code and Run
+================================
+
+```
+$ gcc -o main.cbe main.cbe.c
+$ ls
+main.c  main.cbe  main.cbe.c  main.ll
+$ ./main.cbe
+```