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Which function returns a pair after division ? (integer,frac)
Sep 19, 2023
Vitaliy Fadeev
Sep 19, 2023
Ki Rill
Sep 19, 2023
Vitaliy Fadeev
Sep 19, 2023
claptrap
September 19, 2023
Gravatar of Vitaliy FadeevPosted by Vitaliy FadeevReply
Vitaliy Fadeev
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What D function or D operator does this?

IDIV EAX, r/m32

IDIV 5, 2
 EAX = 2
 EDX = 1

and returns (2,1) at once?

September 19, 2023
Gravatar of Ki RillPosted by Ki Rill
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Ki Rill
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On Tuesday, 19 September 2023 at 03:44:18 UTC, Vitaliy Fadeev wrote:

>

What D function or D operator does this?

IDIV EAX, r/m32

IDIV 5, 2
 EAX = 2
 EDX = 1

and returns (2,1) at once?

You can either use function out parameters with return value or tuples:

import std.typecons;

// with tuples
auto getVal(int a, int b) {
    // ...
    return tuple(integer, frac);
}

// out params
int getVal2(int a, int b, out int frac) {
    // ...

    frac = _fraq;
    return integer;
}

// USAGE
{
    // with tuples
    auto v = getVal(5, 2);
    assert(v[0] == 2);
    assert(v[1] == 1);

    // with out params
    int frac;
    int integer = getVal2(5, 2, frac);
    assert(integer == 2);
    assert(frac == 1);
}
September 19, 2023
Gravatar of Richard (Rikki) Andrew CattermolePosted by Richard (Rikki) Andrew Cattermole
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Richard (Rikki) Andrew Cattermole
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There are no operators for this, not that you need one.

```d
void func(int numerator, int denominator, out int quotient, out int remainder) {
    quotient = numerator / denominator;
    remainder = numerator % denominator;
}
```

This will produce with ldc2 -O3:

```
void example.func(int, int, out int, out int):
        mov     r8, rdx
        mov     eax, edi
        cdq
        idiv    esi
        mov     dword ptr [r8], eax
        mov     dword ptr [rcx], edx
        ret
```

Embrace modern backends, they are amazing!
September 19, 2023
Gravatar of Vitaliy FadeevPosted by Vitaliy Fadeev
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Vitaliy Fadeev
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On Tuesday, 19 September 2023 at 03:53:06 UTC, Richard (Rikki) Andrew Cattermole wrote:
> There are no operators for this, not that you need one.
>
> ```d
> void func(int numerator, int denominator, out int quotient, out int remainder) {
>     quotient = numerator / denominator;
>     remainder = numerator % denominator;
> }
> ```
>
> This will produce with ldc2 -O3:
>
> ```
> void example.func(int, int, out int, out int):
>         mov     r8, rdx
>         mov     eax, edi
>         cdq
>         idiv    esi
>         mov     dword ptr [r8], eax
>         mov     dword ptr [rcx], edx
>         ret
> ```
>
> Embrace modern backends, they are amazing!

Thanks, Rikki. Optimization is good!
May be exist native D function or D-operator, like ```(a,b) = x /% y;``` ?
September 19, 2023
Gravatar of claptrapPosted by claptrap
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claptrap
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On Tuesday, 19 September 2023 at 03:44:18 UTC, Vitaliy Fadeev wrote:

>

What D function or D operator does this?

IDIV EAX, r/m32

IDIV 5, 2
 EAX = 2
 EDX = 1

and returns (2,1) at once?

If you use LDC it'll automatically optimize that for you

https://d.godbolt.org/z/oz4h9ccbP