x86 first bit check (odd check):

AND EAX, EAX  ; update FLAG OF  // odd flag
JO  Label

Is there D-Lang operator of optimized library function ?

On Friday, 22 September 2023 at 14:29:08 UTC, Vitaliy Fadeev wrote:

AND EAX, EAX  ; update FLAG OF  // odd flag
JO  Label

There's no "odd" flag, theres the overflow flag "O", and "JO" is jump on overflow. Or there's the parity flag "P", which signals an odd or even number of bits in the lowest byte of the result (on x86 anyway).

If you just want to test if an int is odd or even, just do

if (x & 1) writeln("is odd");
else writeln("is even");

that'll compile to an AND and a jmp, or conditional move maybe.

If you want to access the parity flag I think you're out of luck aside from using inline asm.

On Friday, 22 September 2023 at 22:48:34 UTC, claptrap wrote:

AND EAX, EAX  ; update FLAG OF  // odd flag
JO  Label

Thank, claptrap!
Yes, P FLAG, of course! JP instruction.

if (x & 1)

I am using the code above.

OK, may be.