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DMD optimizer ( -O) bug
Dec 11, 2003
dickl
Dec 11, 2003
Walter
Dec 11, 2003
Y.Tomino
Dec 12, 2003
Walter
Dec 12, 2003
Y.Tomino
Dec 12, 2003
dickl
December 11, 2003
Gravatar of dicklPosted by dicklReply
dickl
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When compiling without the -O option, the compiler generates the following
code (correctly)
for the functions HIWORD & LOWORD.
--------------------------------------------
WORD HIWORD(int l)
0040902C  enter       4,0
00409030  mov         dword ptr [ebp-4],eax
{
    return (WORD)((l >> 16) & 0xFFFF);
    00409033  mov         eax,dword ptr [l]
    00409036  sar           eax,10h
    00409039  mov         ecx,0FFFFh
    0040903E  and          eax,ecx
}
00409040  leave
00409041  ret
00409042  int         3
00409043  int         3


WORD LOWORD(int l)
00409044  enter       4,0
00409048  mov         dword ptr [ebp-4],eax
{
    return (WORD)l;
    0040904B  mov         ax,word ptr [l]
}

With the -O option used, it does some strange stuff
-----------------------------------------------------
WORD HIWORD(int l)
00408F98  ret
00408F99  int         3
00408F9A  int         3
00408F9B  int         3
{
    return (WORD)((l >> 16) & 0xFFFF);
}

WORD LOWORD(int l)
00408F9C  ret
00408F9D  int         3
00408F9E  int         3
00408F9F  int         3
{
    return (WORD)l;
}
December 11, 2003
Gravatar of WalterPosted by Walter
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Walter
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I get, optimized -O -release on std\c\windows\windows.d:

_HIWORD@4       comdat
        assume  CS:_HIWORD@4
                mov     AX,6[ESP]
                ret     4
_HIWORD@4       ends
_LOWORD@4       comdat
        assume  CS:_LOWORD@4
                mov     AX,4[ESP]
                ret     4
_LOWORD@4       ends

which looks correct.
December 11, 2003
Gravatar of Y.TominoPosted by Y.Tomino
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Y.Tomino
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It seems relying on extern(xx).

YT

-------------------------------------
//dmd -O test.d
alias int ULONG;
alias ushort WORD;

WORD HIWORD(ULONG l)
{
    return (WORD)((l >> 16) & 0xFFFF);
}

extern(Windows) WORD HIWORD_w(ULONG l)
{
    return (WORD)((l >> 16) & 0xFFFF);
}

int main()
{
 printf("%x\n", HIWORD(0x12345678)); //5678
 printf("%x\n", HIWORD_w(0x12345678)); //1234
 return 0;
}
--------------------------------

"Walter" <walter@digitalmars.com> wrote in message news:braobo$2t83$1@digitaldaemon.com...
> I get, optimized -O -release on std\c\windows\windows.d:
>
> _HIWORD@4       comdat
>         assume  CS:_HIWORD@4
>                 mov     AX,6[ESP]
>                 ret     4
> _HIWORD@4       ends
> _LOWORD@4       comdat
>         assume  CS:_LOWORD@4
>                 mov     AX,4[ESP]
>                 ret     4
> _LOWORD@4       ends
>
> which looks correct.
>
>
December 12, 2003
Gravatar of WalterPosted by Walter
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Walter
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I'm not sure what you mean here. Is it working in your tests or not?

"Y.Tomino" <demoonlit@inter7.jp> wrote in message news:brardl$90$1@digitaldaemon.com...
> It seems relying on extern(xx).
>
> YT
>
> -------------------------------------
> //dmd -O test.d
> alias int ULONG;
> alias ushort WORD;
>
> WORD HIWORD(ULONG l)
> {
>     return (WORD)((l >> 16) & 0xFFFF);
> }
>
> extern(Windows) WORD HIWORD_w(ULONG l)
> {
>     return (WORD)((l >> 16) & 0xFFFF);
> }
>
> int main()
> {
>  printf("%x\n", HIWORD(0x12345678)); //5678
>  printf("%x\n", HIWORD_w(0x12345678)); //1234
>  return 0;
> }
> --------------------------------
>
> "Walter" <walter@digitalmars.com> wrote in message news:braobo$2t83$1@digitaldaemon.com...
> > I get, optimized -O -release on std\c\windows\windows.d:
> >
> > _HIWORD@4       comdat
> >         assume  CS:_HIWORD@4
> >                 mov     AX,6[ESP]
> >                 ret     4
> > _HIWORD@4       ends
> > _LOWORD@4       comdat
> >         assume  CS:_LOWORD@4
> >                 mov     AX,4[ESP]
> >                 ret     4
> > _LOWORD@4       ends
> >
> > which looks correct.
> >
> >
>
December 12, 2003
Gravatar of Y.TominoPosted by Y.Tomino
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Y.Tomino
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Posted in reply to Walter


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HIWORD of std.c.windows.windows.d is compiled with extern(Windows). Please test HIWORD for every "LinkageAttribute"  with -O.

HIWORD and HIWORD_w in my test are the same logic.
But These return different values.

> >  printf("%x\n", HIWORD(0x12345678)); //5678
The result is 0x5678.
incorrect
> >  printf("%x\n", HIWORD_w(0x12345678)); //1234
The result is 0x1234.
correct

extern(Windows) HIWORD is correct.
extern(D) HIWORD is incorrect. (dickl probably wrote this case)

Thanks.
YT

"Walter" <walter@digitalmars.com> wrote in message news:brbcro$opk$1@digitaldaemon.com...
> I'm not sure what you mean here. Is it working in your tests or not?
>
> "Y.Tomino" <demoonlit@inter7.jp> wrote in message news:brardl$90$1@digitaldaemon.com...
> > It seems relying on extern(xx).
> >
> > YT
> >
> > -------------------------------------
> > //dmd -O test.d
> > alias int ULONG;
> > alias ushort WORD;
> >
> > WORD HIWORD(ULONG l)
> > {
> >     return (WORD)((l >> 16) & 0xFFFF);
> > }
> >
> > extern(Windows) WORD HIWORD_w(ULONG l)
> > {
> >     return (WORD)((l >> 16) & 0xFFFF);
> > }
> >
> > int main()
> > {
> >  printf("%x\n", HIWORD(0x12345678)); //5678
> >  printf("%x\n", HIWORD_w(0x12345678)); //1234
> >  return 0;
> > }
> > --------------------------------
> >
> > "Walter" <walter@digitalmars.com> wrote in message news:braobo$2t83$1@digitaldaemon.com...
> > > I get, optimized -O -release on std\c\windows\windows.d:
> > >
> > > _HIWORD@4       comdat
> > >         assume  CS:_HIWORD@4
> > >                 mov     AX,6[ESP]
> > >                 ret     4
> > > _HIWORD@4       ends
> > > _LOWORD@4       comdat
> > >         assume  CS:_LOWORD@4
> > >                 mov     AX,4[ESP]
> > >                 ret     4
> > > _LOWORD@4       ends
> > >
> > > which looks correct.
> > >
> > >
> >
>
>
December 12, 2003
Gravatar of dicklPosted by dickl
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dickl
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It was compiled as extern(D)

----------------------------------
"Y.Tomino" <demoonlit@inter7.jp> wrote in message news:brc86e$2145$1@digitaldaemon.com...
> HIWORD of std.c.windows.windows.d is compiled with extern(Windows). Please test HIWORD for every "LinkageAttribute"  with -O.
>
> HIWORD and HIWORD_w in my test are the same logic.
> But These return different values.
>
> > >  printf("%x\n", HIWORD(0x12345678)); //5678
> The result is 0x5678.
> incorrect
> > >  printf("%x\n", HIWORD_w(0x12345678)); //1234
> The result is 0x1234.
> correct
>
> extern(Windows) HIWORD is correct.
> extern(D) HIWORD is incorrect. (dickl probably wrote this case)
>
> Thanks.
> YT
>
> "Walter" <walter@digitalmars.com> wrote in message news:brbcro$opk$1@digitaldaemon.com...
> > I'm not sure what you mean here. Is it working in your tests or not?
> >
> > "Y.Tomino" <demoonlit@inter7.jp> wrote in message news:brardl$90$1@digitaldaemon.com...
> > > It seems relying on extern(xx).
> > >
> > > YT
> > >
> > > -------------------------------------
> > > //dmd -O test.d
> > > alias int ULONG;
> > > alias ushort WORD;
> > >
> > > WORD HIWORD(ULONG l)
> > > {
> > >     return (WORD)((l >> 16) & 0xFFFF);
> > > }
> > >
> > > extern(Windows) WORD HIWORD_w(ULONG l)
> > > {
> > >     return (WORD)((l >> 16) & 0xFFFF);
> > > }
> > >
> > > int main()
> > > {
> > >  printf("%x\n", HIWORD(0x12345678)); //5678
> > >  printf("%x\n", HIWORD_w(0x12345678)); //1234
> > >  return 0;
> > > }
> > > --------------------------------
> > >
> > > "Walter" <walter@digitalmars.com> wrote in message news:braobo$2t83$1@digitaldaemon.com...
> > > > I get, optimized -O -release on std\c\windows\windows.d:
> > > >
> > > > _HIWORD@4       comdat
> > > >         assume  CS:_HIWORD@4
> > > >                 mov     AX,6[ESP]
> > > >                 ret     4
> > > > _HIWORD@4       ends
> > > > _LOWORD@4       comdat
> > > >         assume  CS:_LOWORD@4
> > > >                 mov     AX,4[ESP]
> > > >                 ret     4
> > > > _LOWORD@4       ends
> > > >
> > > > which looks correct.
> > > >
> > > >
> > >
> >
> >
>