Thread overview | |||||
---|---|---|---|---|---|
|
December 07, 2006 a case where static foreach dosn't work "correctly" | ||||
---|---|---|---|---|
| ||||
If a static foreach is given a tuple of const ints, the ints don't behave like consts inside of the foreach body. I havent checked other cases but you can't use them for array indexes in ASM operations: voif fn(V...)() { const int i = 0 int[3] array; foreach(j, V) { asm { mov EAX, array[i]; // works mov EAX, array[j]; // fails } } } Why does this matter you ask? It would allow this to work: /***** unsigned big int with "size" words of precision */ template BigNum(uint size) { static if(size == 0) static assert(false, "BigNum!(1) is not valid"); else static if(size == 1) static assert(false, "BigNum!(1) is not implemented"); else static if(size == 2) alias use!(1, 1) start; else alias build!(size, size-2, size-1) start; } template build(uint size, uint i, V...) { static if(i==1) alias use!(size, 1, V) build; else alias build!(size, i-1, i, V) build; } template use(uint size, V...) { struct use { uint[size] valuse; use!(size, V).use opAdd(use!(size, V).use to) { uint[size] mine, other; mine[] = valuse; other[] = to.valuse[]; asm { mov EAX, mine[0]; add other[0], EAX; } foreach(i; V) { asm { mov EAX, mine[i]; // this fails adc other[i], EAX; } } use!(size, V).use ret; ret.valuse[] = other; return ret; } } } DMD 0.174 |
December 07, 2006 Re: a case where static foreach dosn't work "correctly" | ||||
---|---|---|---|---|
| ||||
Posted in reply to BCS | Have you tried to do the same with DMD 0.176 ?
Maybe the bug is already solved in one of the two big massacres!
BCS wrote:
> If a static foreach is given a tuple of const ints, the ints don't behave like consts inside of the foreach body. I havent checked other cases but you can't use them for array indexes in ASM operations:
>
>
> voif fn(V...)()
> {
> const int i = 0
> int[3] array;
>
> foreach(j, V)
> {
> asm
> {
> mov EAX, array[i]; // works
> mov EAX, array[j]; // fails
> }
> }
> }
>
>
> Why does this matter you ask? It would allow this to work:
>
>
> /***** unsigned big int with "size" words of precision */
>
> template BigNum(uint size)
> {
> static if(size == 0)
> static assert(false, "BigNum!(1) is not valid");
> else static if(size == 1)
> static assert(false, "BigNum!(1) is not implemented");
> else static if(size == 2)
> alias use!(1, 1) start;
> else
> alias build!(size, size-2, size-1) start;
> }
>
> template build(uint size, uint i, V...)
> {
> static if(i==1)
> alias use!(size, 1, V) build;
> else
> alias build!(size, i-1, i, V) build;
> }
>
> template use(uint size, V...)
> {
> struct use
> {
> uint[size] valuse;
> use!(size, V).use opAdd(use!(size, V).use to)
> {
> uint[size] mine, other;
> mine[] = valuse;
> other[] = to.valuse[];
> asm
> {
> mov EAX, mine[0];
> add other[0], EAX;
> }
> foreach(i; V)
> {
> asm
> {
> mov EAX, mine[i]; // this fails
> adc other[i], EAX;
> }
> }
> use!(size, V).use ret;
> ret.valuse[] = other;
> return ret;
> }
> }
> }
>
>
> DMD 0.174
|
December 07, 2006 Re: a case where static foreach dosn't work "correctly" | ||||
---|---|---|---|---|
| ||||
Posted in reply to Alexander Panek | Alexander Panek wrote: > Have you tried to do the same with DMD 0.176 ? > Maybe the bug is already solved in one of the two big massacres! > It wasn't, but I fond a work around (and a few typos), here's the latest: /***** unsigned big int with "size" words of precision */ alias BigNum(4) uCent; template BigNum(uint size) { static if(size == 0) static assert(false, "BigNum!(1) is not valid"); else static if(size == 1) static assert(false, "BigNum!(1) is not implemented"); else static if(size == 2) alias use!(1, 1) BigNum; else alias build!(size, size-2, size-1) BigNum; } template build(uint size, uint i, V...) { static if(i==1) alias use!(size, 1, V) build; else alias build!(size, i-1, i, V) build; } template use(uint size, V...) { struct use { uint[size] valuse; use!(size, V) opAdd(use!(size, V) to) { uint[size] mine, other; mine[] = valuse; other[] = to.valuse[]; asm { mov EAX, mine[0]; add other[0], EAX; } foreach(j,i; V) { const uint off = V[j]; // this is a work-around asm { mov EAX, mine[off]; adc other[off], EAX; } } use!(size, V) ret; ret.valuse[] = other; return ret; } use!(size, V) opSub(use!(size, V) to) { uint[size] mine, other; mine[] = valuse; other[] = to.valuse[]; asm { mov EAX, mine[0]; sub other[0], EAX; } foreach(j,i; V) { const uint off = V[j]; asm { mov EAX, mine[off]; sbb other[off], EAX; } } use!(size, V) ret; ret.valuse[] = other; return ret; } } } > BCS wrote: > >> If a static foreach is given a tuple of const ints, the ints don't behave like consts inside of the foreach body. I havent checked other cases but you can't use them for array indexes in ASM operations: [...] >> >> Why does this matter you ask? It would allow this to work: >> >> |
Copyright © 1999-2021 by the D Language Foundation