• Vitaliy Fadeev (6/6) Sep 22 2023 x86 first bit check (odd check):
• claptrap (12/18) Sep 22 2023 There's no "odd" flag, theres the overflow flag "O", and "JO" is
• Vitaliy Fadeev (8/28) Sep 22 2023 Thank, claptrap!

Vitaliy Fadeev <vital.fadeev gmail.com> writes:

x86 first bit check (odd check):
```asm
AND EAX, EAX  ; update FLAG OF  // odd flag
JO  Label
```

Is there D-Lang operator of optimized library function ?

claptrap <clap trap.com> writes:

On Friday, 22 September 2023 at 14:29:08 UTC, Vitaliy Fadeev 
wrote:
 x86 first bit check (odd check):
 ```asm
 AND EAX, EAX  ; update FLAG OF  // odd flag
 JO  Label
 ```

 Is there D-Lang operator of optimized library function ?

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.

Vitaliy Fadeev <vital.fadeev gmail.com> writes:

On Friday, 22 September 2023 at 22:48:34 UTC, claptrap wrote:
 On Friday, 22 September 2023 at 14:29:08 UTC, Vitaliy Fadeev 
 wrote:
 x86 first bit check (odd check):
 ```asm
 AND EAX, EAX  ; update FLAG OF  // odd flag
 JO  Label
 ```

 Is there D-Lang operator of optimized library function ?

 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.

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

```asm
if (x & 1)
```
I am using the code above.

 using inline asm

OK, may be.