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 sequence
does get generated sometimes) and it can be simplified to just "testb
$1,(memory)", reading only 1 byte instead of all 4 (the AND instruction
would have masked out the upper 3 bytes).
Gareth aka. Kit
On 30/06/2022 11:52, Thorsten Otto via fpc-devel wrote:
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 the register against
zero. SO you canot do such "optimizations"
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