Re: [ros-dev] [ros-diffs] [sginsberg] 42829: - svchost: #ifdef _MSC_VER doesn't mean "using Microsoft's headers" anymore - ddraw, imm32, msxml3, oleaut32, riched20: Include typeof.h for typeof emulation when compiling under MSVC and remove from React

[Wladimir A. Jimenez B.]

Filip:

*NetworkAddressLength = (UINT)((j+1)/2);

Do not equal to
> if ((j % 2) == 0)     //////    if  even
> {
>    *NetworkAddressLength = (UINT)(j/2);
> }
> else
> {
>    *NetworkAddressLength = (UINT)((j/2)+1);
> }

2009/8/23 Filip Navara [e-mail]
> On Fri, Aug 21, 2009 at 5:57 PM, [e-mail] wrote:
> > --- trunk/reactos/drivers/network/ndis/ndis/config.c [iso-8859-1]
>
> (original)
> > +++ trunk/reactos/drivers/network/ndis/ndis/config.c [iso-8859-1] Fri Aug
>
> 21 17:57:26 2009
> > @@ -705,7 +705,14 @@
> > while (j < str.Length && str.Buffer[j] != '\0') j++;
> >
> > *NetworkAddressLength = (UINT)((j/2)+0.5);
> > if ((j % 2) == 0)
> > {
> >    *NetworkAddressLength = (UINT)(j/2);
> > }
> > else
> > {
> >    *NetworkAddressLength = (UINT)((j/2)+1);
> > }
>
> Why not use  *NetworkAddressLength = (UINT)((j+1)/2); unconditionally?
> > if ((*NetworkAddressLength) == 0)
> > {
>
> F.
>
> Ros-dev mailing list
> [e-mail]
> http://www.reactos.org/mailman/listinfo/ros-dev
-- 
----------------------------------------
Wladimir A. Jiménez B.
http://www.kasbeel.cl
Linux User # 444661
Ubuntu User # 19201

[mrnobo1024]

--- On Fri, 9/11/09, Wladimir A. Jimenez B. [e-mail] wrote:
> Filip:
>
> *NetworkAddressLength =
> (UINT)((j+1)/2); 
> Do not equal to
> > if ((j % 2) == 0)     //////  if  even
> > {
> > *NetworkAddressLength = (UINT)(j/2);
> > }
> > else
> > {
> > *NetworkAddressLength = (UINT)((j/2)+1);
> > }

The only time when they would differ is if j == UINT_MAX (the shorter version would overflow). But that can never happen, since j is the length of a string.

[Jose Catena]

To check odd / even we should always use:

// if odd

If (x & 1)

// if even

If (!x & 1)

% is very slow.

Jose Catena

DIGIWAVES S.L.

From: [e-mail] [mailto:[e-mail]] On
Behalf Of Wladimir A. Jimenez B.
Sent: Friday, 11 September, 2009 16:56
To: ReactOS Development List
Subject: Re: [ros-dev] [ros-diffs] [sginsberg] 42829: - svchost: #ifdef
_MSC_VER doesn't mean "using Microsoft's headers" anymore - ddraw, imm32,
msxml3, oleaut32, riched20: Include typeof.h for typeof emulation when
compiling under MSVC and remove from React

Filip:

*NetworkAddressLength = (UINT)((j+1)/2);

Do not equal to
> if ((j % 2) == 0)     //////    if  even
> {
>    *NetworkAddressLength = (UINT)(j/2);     
> }
> else
> {
>    *NetworkAddressLength = (UINT)((j/2)+1);  
> }

2009/8/23 Filip Navara [e-mail]

On Fri, Aug 21, 2009 at 5:57 PM, [e-mail] wrote:
> --- trunk/reactos/drivers/network/ndis/ndis/config.c [iso-8859-1]

(original)
> +++ trunk/reactos/drivers/network/ndis/ndis/config.c [iso-8859-1] Fri Aug

21 17:57:26 2009
> @@ -705,7 +705,14 @@
> while (j < str.Length && str.Buffer[j] != '\0') j++;
>
> *NetworkAddressLength = (UINT)((j/2)+0.5);
> if ((j % 2) == 0)
> {
>    *NetworkAddressLength = (UINT)(j/2);
> }
> else
> {
>    *NetworkAddressLength = (UINT)((j/2)+1);
> }

Why not use  *NetworkAddressLength = (UINT)((j+1)/2); unconditionally?
> if ((*NetworkAddressLength) == 0)
> {

F.

_______________________________________________
Ros-dev mailing list
[e-mail]
http://www.reactos.org/mailman/listinfo/ros-dev
-- 
----------------------------------------
Wladimir A. Jiménez B.
http://www.kasbeel.cl
Linux User # 444661
Ubuntu User # 19201

[Alex Ionescu]

"If (!x & 1)" is the most horrible way to write this. To most people
it means "NOT X AND 1", what you want is NOT(X AND 1).

Best regards,
Alex Ionescu

On Fri, Sep 11, 2009 at 7:31 PM, Jose Catena [e-mail] wrote:
> To check odd / even we should always use:
>
> // if odd
>
> If (x & 1)
>
> // if even
>
> If (!x & 1)
>
> % is very slow.
>
> Jose Catena
>
> DIGIWAVES S.L.
>
> From: [e-mail] [mailto:[e-mail]] On
> Behalf Of Wladimir A. Jimenez B.
> Sent: Friday, 11 September, 2009 16:56
> To: ReactOS Development List
> Subject: Re: [ros-dev] [ros-diffs] [sginsberg] 42829: - svchost: #ifdef
> _MSC_VER doesn't mean "using Microsoft's headers" anymore - ddraw, imm32,
> msxml3, oleaut32, riched20: Include typeof.h for typeof emulation when
> compiling under MSVC and remove from React
>
> Filip:
>
> *NetworkAddressLength = (UINT)((j+1)/2);
>
> Do not equal to
> > if ((j % 2) == 0)     //////    if  even
> > {
> > *NetworkAddressLength = (UINT)(j/2);
> > }
> > else
> > {
> > *NetworkAddressLength = (UINT)((j/2)+1);
> > }
>
> 2009/8/23 Filip Navara [e-mail]
>
> On Fri, Aug 21, 2009 at 5:57 PM, [e-mail] wrote:
> > --- trunk/reactos/drivers/network/ndis/ndis/config.c [iso-8859-1]
> > (original)
> > +++ trunk/reactos/drivers/network/ndis/ndis/config.c [iso-8859-1] Fri Aug
> > 21 17:57:26 2009
> > @@ -705,7 +705,14 @@
> >
> > while (j < str.Length && str.Buffer[j] != '\0') j++;
> > *NetworkAddressLength = (UINT)((j/2)+0.5);
> > if ((j % 2) == 0)
> > {
> > *NetworkAddressLength = (UINT)(j/2);
> > }
> > else
> > {
> > *NetworkAddressLength = (UINT)((j/2)+1);
> > }
>
> Why not use  *NetworkAddressLength = (UINT)((j+1)/2); unconditionally?
> > if ((*NetworkAddressLength) == 0)
> >     {
>
> F.
>
> Ros-dev mailing list
> [e-mail]
> http://www.reactos.org/mailman/listinfo/ros-dev
> --
>
> Wladimir A. Jiménez B.
> http://www.kasbeel.cl
> Linux User # 444661
> Ubuntu User # 19201
>
> Ros-dev mailing list
> [e-mail]
> http://www.reactos.org/mailman/listinfo/ros-dev

[Jose Catena]

Instead of (UINT)((j/2)+0.5)

Better (UINT)((j+1)>>1)

Much faster, and avoids unnecessary FPU and division usage. Many compilers
will translate /2 to >>1, but none will change the way of rounding.

Jose Catena

DIGIWAVES S.L.

From: [e-mail] [mailto:[e-mail]] On
Behalf Of Wladimir A. Jimenez B.
Sent: Friday, 11 September, 2009 16:56
To: ReactOS Development List
Subject: Re: [ros-dev] [ros-diffs] [sginsberg] 42829: - svchost: #ifdef
_MSC_VER doesn't mean "using Microsoft's headers" anymore - ddraw, imm32,
msxml3, oleaut32, riched20: Include typeof.h for typeof emulation when
compiling under MSVC and remove from React

2009/8/23 Filip Navara [e-mail]

On Fri, Aug 21, 2009 at 5:57 PM, [e-mail] wrote:
> --- trunk/reactos/drivers/network/ndis/ndis/config.c [iso-8859-1]

(original)
> +++ trunk/reactos/drivers/network/ndis/ndis/config.c [iso-8859-1] Fri Aug

21 17:57:26 2009
> @@ -705,7 +705,14 @@
> while (j < str.Length && str.Buffer[j] != '\0') j++;
>
> *NetworkAddressLength = (UINT)((j/2)+0.5);
> if ((j % 2) == 0)
> {
>    *NetworkAddressLength = (UINT)(j/2);
> }
> else
> {
>    *NetworkAddressLength = (UINT)((j/2)+1);
> }

Why not use  *NetworkAddressLength = (UINT)((j+1)/2); unconditionally?
> if ((*NetworkAddressLength) == 0)
> {

F.

_______________________________________________
Ros-dev mailing list
[e-mail]
http://www.reactos.org/mailman/listinfo/ros-dev
-- 
----------------------------------------
Wladimir A. Jiménez B.
http://www.kasbeel.cl
Linux User # 444661
Ubuntu User # 19201

[Dmitry Gorbachev]

Hi,
> Better (UINT)((j+1)>>1)

Where have you been 3 weeks ago? :) Somebody already implemented it:
http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/network/ndis/ndis/config.c?revision=42838&view=markup#l_708
> // if even
>
> If (!x & 1)

If the code and the comments disagree, then both are probably wrong. ;)

[Jose Catena]

> > // if even
> > If (!x & 1)
> If the code and the comments disagree, then both are probably wrong. ;)

Indeed, I was wrong in the even example. It's:
if (~x & 1)
// or
if (!(x & 1))

And yes, I just saw it was already implemented, sorry.

Jose Catena
DIGIWAVES S.L.