Lecture 7: Procedures
Sec 6 of x86-64 textbook supplement

Sample code used in lecture to illustrate
function call, return and register conventions

Compiles for x86-64
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fac.txt is a trimmed version of fac.s

# generate fac.s
gcc -O2 -S loop.c

# generate fac
gcc -O2 -o loop loop.c
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