Some divisors, like 7, do not have a reciprocal that can be contained within 32
bits. Expanding to
64 bits, however, is a clever approach that I overlooked, since you can permit
some loss of
precision (the reason why the bit shift is required) due to the limited range.
This might be worth
On Tue, Aug 24, 2021 at 3:05 PM Sven Barth via fpc-devel
wrote:
> Wrong. If it would be a 64-bit DLL in System32 of a x86_64 system then there
> would be no problem. However a 64-bit DLL in the SysWOW64 directory
> (thus the 32-bit System32 directory) *is* a problem. Same for a 32-bit DLL in
>
I came up with even shorter variant of div
example
function teDWordDivBy7_v4( divided : dword):dword; assembler; nostackframe;
asm
mov ecx,divided
mov rax,2635249153693862181
mul rcx
mov eax,edx
end;
current version for comparison
function teDWordDivBy7_v0( divided :
Am 23.08.2021 um 18:14 schrieb Marco van de Voort via fpc-devel:
[...] I notice is that you point lazarus to the ppu's in the FPC
source tree [...]
Sorry, I don't understand: There is no Lazarus involved in my build
script. If there is, show me the line and how you would modify it.
Bart via fpc-devel schrieb am Di., 24.
Aug. 2021, 06:31:
> On Mon, Aug 23, 2021 at 3:35 PM Yuriy Sydorov via fpc-devel
> wrote:
>
> > Just move common.dll from SysWOW64 to system32. The file is placed
> wrongly
> > by some installer.
>
> If I understand Tomas correctly then that would not make
I was over exited of making working example for byte div case. For word case it can be done.
In case of dword div it's not so nice. It's theoretically possible to shave 1 cpu clock cycle. And i have no working example jet. Sorry, for spreading false hope.
example for byte case:
function
if you have not bout book you can always try search in internet.
I did some research in magic div constants. As already known, there are good case where you can replace division by
mov magic
mul
shr
and bad case
mov magic
mul
add
rcr
shr
Bad cases are approximately 1/3 of all cases.
For
