Re: [dev] [sbase][patch] find: change execv to execvp

From: <k0ga_AT_shike2.com>
Date: Sat, 21 Feb 2015 19:17:43 +0100

>
> For 32 Bit / 64 Bit machines (assuming int is 32 bit and char is 8 bit).
> Signed, unsigned makes no difference, assuming self-aligned (which is the
> case on x86, x86_64 and ARM):
>

If the char is signed you have to do bit sign extension, and for
example transform 0x81 into 0xffffff81. Depend of the processor it
can be done with only one instruction but in anothers you have to
check the upper bit and branch based in its value. If the char is
unsigned you always have to clear the upper bytes, so in the case of
signed the code is longer and non linear (or even worse, the compiler
calls an internal function to do the bit expansion).

Regards,
Received on Sat Feb 21 2015 - 19:17:43 CET