-rw-r--r-- 225 saferewrite-20210903/src/encode_761x1531round/README
gcc -O3 needs Iop_QNarrowBin32Sto16Ux8 for ref, currently (2021.09.01)
not supported by angr, but clang -O1 works.

2021.09.02 update: The angr developers have now added support in the
master branch; still have to test this.