jonsykkel[asciilifeform]: re ch13:
jonsykkel[asciilifeform]: 1. did u consider this kinda algo http://zzz.st/up/wVl3rn2q/ (no idea how to do the weird ada aray indexing)
jonsykkel[asciilifeform]: 2. FZ_ShiftRight_O_I with count=0 relys on Shift_Left(x, bitness) shifting all bits out of existence, which raises folowing sub-questions:
jonsykkel[asciilifeform]: 2a. dose ada standard guarante this? im couldnt find anything about it in pdf
jonsykkel[asciilifeform]: 2b. x86 masks the shift count so "shl rax, 64" dosnt do anything, so it must compile to som sort of conditional or weird thing. i chekd asebly output from my gnat, it semed to produce not a jump but cmp 0x40 then cmov
jonsykkel[asciilifeform]: 3. new w_borow function sems to result in somwat slower code, using all compilers i had lying around. duno how to explain that but intresting. the mod exp from ch7 http://zzz.st/up/bcOOg3it/
jonsykkel[asciilifeform]: i supose my algo creates difrent memory aces patern based on sekrit shift count
asciilifeform: jonsykkel: aaaha
asciilifeform: not so 'quiet', is it, then.
jonsykkel[asciilifeform]: yes i undersand now
jonsykkel[asciilifeform]: CONSTANT-SPACETIME
asciilifeform: right
asciilifeform: re w_borrow & shift -- these arguably belong asm'ified (as later bvt did) in practice
asciilifeform: the ada version is 'canonical' tho, and if jonsykkel (or anyone else) finds bug (incl. branches/accesses on seekrit bitz) in it, asciilifeform would much like to hear about it
asciilifeform: speedups of const factor in the ada not nearly so much of a concern tho
asciilifeform: (speed-sensitive applications oughta use asmified word arithmetic & carries)
jonsykkel[asciilifeform]: naturaly. question 2b re shift was about constanttimeness of generated code tho