Both clang and gcc seem to do this
> On 30/06/2022 17:28 CEST J. Gareth Moreton via fpc-devel
> wrote:
>
>
> This was what I was working on:
>
> https://gitlab.com/freepascal.org/fpc/source/-/merge_requests/252
>
> The same question applies regarding the TEST instruction, but it's a
> litt
This was what I was working on:
https://gitlab.com/freepascal.org/fpc/source/-/merge_requests/252
The same question applies regarding the TEST instruction, but it's a
little more restrictive in this instance in that it's determined that
the program doesn't care about the upper bytes of the reg
Yeah, I just realised I was pretty silly to miss that! I must be more
tired than I thought!
The reason why I brought it up is because I found an upgrade to the
"MovAndTest2Test" optimisation where you might have something like "movl
%eax,(memory); andl $1,%eax; testb %al;%al" (Yes, that code s
On Montag, 27. Juni 2022 04:43:46 CEST J. Gareth Moreton via fpc-devel wrote:
> testl$1,%ebx -> testb$1,%bl
Obviously, thats not the same. The latter will only compare the least-
significant byte against 1, and ignore the rest of the register. The former
will also compare the remainder of
On 27-6-2022 04:43, J. Gareth Moreton via fpc-devel wrote:
Hi everyone,
I'm playing around with a peephole optimization (back to my roots!) and
I've come across a relatively simple one that aims to reduce instruction
size occasionally. One part involves reducing the opsize if the
constant
Hi everyone,
I'm playing around with a peephole optimization (back to my roots!) and
I've come across a relatively simple one that aims to reduce instruction
size occasionally. One part involves reducing the opsize if the
constant is numeric. For example:
testl $17,76(%rcx) -> testb $17
