Thread overview
What is the __udivdi3 __umoddi3 function?
Aug 22
lili
Aug 23
lili
August 22
Hi
  I writing a OS in D, compile with -betterC -c, but when call a variable template function
  where has __udivdi3  __umoddi3 undefined symbol, can not link with ld,  how to resolve it.
  see code below
println('it is ok');
println('it is occur -_udivdi3 symbol', 33);

 void println(A...)(A a)
    {
        char[20] numStr = void;

        import std.traits;
        foreach(v ; a) {
            alias UV = Unqual!(typeof(v));
            static if (is(UV == char)) putc(v);
            else static if (is(UV == char*)) puts(v);
            else static if (is(typeof(v) == string)) puts(v.ptr);
            else static if (is(UV == bool)) puts(v ? "true":"false");
            else static if (is(UV == byte)  || is(UV == ubyte) ||
                     is(UV == short) || is(UV == ushort) ||
                     is(UV == int)   || is(UV == uint) ||
                     is(UV == long)  || is(UV == ulong))
            {

                ulong n = cast(ulong)v;
                bool isNeg = false;
                if (v < 0) {
                    isNeg = true;
                    if (n != 1UL<<63)
                        n = -v;
                }

                int i=0;
                while(n !=0 ) {
                    numStr[i++] = (n%10) + '0';
                    n/=10;
                }

                if (isNeg)
                    putc('-');

                while (--i >= 0)
                    putc(numStr[i]);
            }
            else
                static assert(false);
        }
    }
August 22
Hi there,

On 22 Aug 2019, at 21:20, lili via digitalmars-d-ldc wrote:
>   I writing a OS in D, compile with -betterC -c, but when call a variable template function
>   where has __udivdi3  __umoddi3 undefined symbol, can not link with ld,  how to resolve it.
>   see code below

These are software implementations of integer arithmetic where the desired operation is not natively available on the target CPU (e.g. 64 bit integer division on a 32 bit target).

You can find an implementation in the compiler-rt project (or libgcc), which you can link into your kernel as needed. You might be able to get around this by not using 64 bit integers in your code if 32 bits suffice.

 — David
August 23
On Thursday, 22 August 2019 at 20:39:32 UTC, David Nadlinger wrote:
> Hi there,
>
> On 22 Aug 2019, at 21:20, lili via digitalmars-d-ldc wrote:
>>   I writing a OS in D, compile with -betterC -c, but when call a variable template function
>>   where has __udivdi3  __umoddi3 undefined symbol, can not link with ld,  how to resolve it.
>>   see code below
>
> These are software implementations of integer arithmetic where the desired operation is not natively available on the target CPU (e.g. 64 bit integer division on a 32 bit target).
>
> You can find an implementation in the compiler-rt project (or libgcc), which you can link into your kernel as needed. You might be able to get around this by not using 64 bit integers in your code if 32 bits suffice.
>
>  — David

Thanks a lot.