llvm

1 use the cc1 for generating IR:
clang -cc1 -emit-llvm testfile.c -o testfile.ll
http://llvm.org/docs/LangRef.html
2 To convert LLVM IR in test.ll to bitcode format,
llvm-as test.ll –o test.bc
hexdump -C test.bc
http://llvm.org/docs/BitCodeFormat.html#abstract
3 Converting LLVM bitcode to target machine assembly
llc test.bc –o test.s
clang -S test.bc -o test.s –fomit-frame-pointer

https://github.com/facebook/chisel

http://lldb.llvm.org/lldb-gdb.html

https://developer.apple.com/library/mac/documentation/IDEs/Conceptual/gdb_to_lldb_transition_guide/document/lldb-command-examples.html

https://developer.apple.com/library/mac/documentation/IDEs/Conceptual/gdb_to_lldb_transition_guide/document/lldb-terminal-workflow-tutorial.html