25 Jul
2016
25 Jul
'16
1:34 p.m.
It was thus said that the Great Peter Corlett once stated:
Unsurprisingly, the x86 ISA is brain-damaged here, in that some instructions
(e.g. inc") only affect some bits in EFLAGS, which causes a partial register
stall. The recommended "fix" is to avoid such instructions.
I'm not following this. On the x86, the INC instruction modifies the
following flags: O, S, Z, A and P. So okay, I need to avoid INC to prevent
a partial register stall, therefore, I need to use ADD. Let me check ...
hmm ... ADD modifies the following: O, S, Z, A, P and C. So now I need to
avoid ADD as well? I suppose I could use LEA but then there goes my bignum
addition routine ...
-spc (Or am I missing something?)