EFLAGS bit meaning
http://reverseengineering.stackexchange.com/a/9222

GCC inline assembly
http://ibiblio.org/gferg/ldp/GCC-Inline-Assembly-HOWTO.html

Popping the FPU stack
http://stackoverflow.com/a/33575875/768582

Decoding a sample snippet of asm
http://stackoverflow.com/questions/9186150/decoding-and-understanding-assembly-code

GNU assembler examples
http://cs.lmu.edu/~ray/notes/gasexamples/

GCC function attributes (see "naked")
https://gcc.gnu.org/onlinedocs/gcc-4.3.5/gcc/Function-Attributes.html

Fast floating point sign
http://stackoverflow.com/a/2508911/768582

AMD assembly reference
http://developer.amd.com/wordpress/media/2012/10/26569_APM_v51.pdf

Moving values between SSE and FPU
http://stackoverflow.com/questions/37567154/intel-x86-64-assembly-how-to-move-between-x87-and-sse2-calculating-arctangent#37573264