wried integer addition

[tikviva]

Hi, I have a question regarding to integer addition.

Here is the problem.

I have an integer, x = 0x00000001
and I also have another integer, y = 0xffffff94

Is there any method to concatenate x & y, so that x = 0x00000194 ?
Thanks for the help. =)

God bless,
tikviva

[Andrey Tarasevich]

Re: wried integer addition

tikviva wrote:[color=blue]
> ...
> I have an integer, x = 0x00000001
> and I also have another integer, y = 0xffffff94
>
> Is there any method to concatenate x & y, so that x = 0x00000194 ?
> ...[/color]

I don't see how concatenating 0x00000001 and 0xffffff94 might produce
0x00000194. What kind of "concatenat ion" are you talking about? Why did
you call it "concatenat ion" in the first place?

--
Best regards,
Andrey Tarasevich

[Patrik Stellmann]

Re: wried integer addition

tikviva wrote:
[color=blue]
> Hi, I have a question regarding to integer addition.
>
> Here is the problem.
>
> I have an integer, x = 0x00000001
> and I also have another integer, y = 0xffffff94
>
> Is there any method to concatenate x & y, so that x = 0x00000194 ?
> Thanks for the help. =)[/color]
So you're looking for a function that takes 2 integers and returns
0x00000194 if the input is 0x00000001 and 0xffffff94?

int f(int x, int y)
{
return 0x00000194;
}

Ok, probably not what you were looking for but it's difficult to create
a reasonable function when given only 1 input-output pair...

Maybe you want to take the 1 of x and place at infront of the 94 of y?
Then the function would look like this (i think):
return (x << 8) | (y & 0xFF);

[Karl Heinz Buchegger]

Re: wried integer addition

Patrik Stellmann wrote:[color=blue]
>
> tikviva wrote:
>[color=green]
> > Hi, I have a question regarding to integer addition.
> >
> > Here is the problem.
> >
> > I have an integer, x = 0x00000001
> > and I also have another integer, y = 0xffffff94
> >
> > Is there any method to concatenate x & y, so that x = 0x00000194 ?
> > Thanks for the help. =)[/color]
> So you're looking for a function that takes 2 integers and returns
> 0x00000194 if the input is 0x00000001 and 0xffffff94?
>
> int f(int x, int y)
> {
> return 0x00000194;
> }
>
> Ok, probably not what you were looking for but it's difficult to create
> a reasonable function when given only 1 input-output pair...
>
> Maybe you want to take the 1 of x and place at infront of the 94 of y?
> Then the function would look like this (i think):
> return (x << 8) | (y & 0xFF);[/color]

You forgot about the 0xfffff part, which has to be masked away (if
your theory of what the function should do holds)

return ( (x & ~0xff) << 8 ) | ( y & 0xff );

--
Karl Heinz Buchegger
kbuchegg@gascad .at

[Karl Heinz Buchegger]

Re: wried integer addition

Karl Heinz Buchegger wrote:[color=blue]
>
> Patrik Stellmann wrote:[color=green]
> >
> > tikviva wrote:
> >[color=darkred]
> > > Hi, I have a question regarding to integer addition.
> > >
> > > Here is the problem.
> > >
> > > I have an integer, x = 0x00000001
> > > and I also have another integer, y = 0xffffff94
> > >
> > > Is there any method to concatenate x & y, so that x = 0x00000194 ?
> > > Thanks for the help. =)[/color]
> > So you're looking for a function that takes 2 integers and returns
> > 0x00000194 if the input is 0x00000001 and 0xffffff94?
> >
> > int f(int x, int y)
> > {
> > return 0x00000194;
> > }
> >
> > Ok, probably not what you were looking for but it's difficult to create
> > a reasonable function when given only 1 input-output pair...
> >
> > Maybe you want to take the 1 of x and place at infront of the 94 of y?
> > Then the function would look like this (i think):
> > return (x << 8) | (y & 0xFF);[/color]
>
> You forgot about the 0xfffff part, which has to be masked away (if
> your theory of what the function should do holds)
>
> return ( (x & ~0xff) << 8 ) | ( y & 0xff );
>[/color]


grr.
That's the problem with bit operations: It is easy to read something
into a source code which is not written there.

Your function was fine.

--
Karl Heinz Buchegger
kbuchegg@gascad .at

[Patrik Stellmann]

Re: wried integer addition



Karl Heinz Buchegger wrote:[color=blue]
> Patrik Stellmann wrote:
>[color=green]
>>tikviva wrote:
>>
>>[color=darkred]
>>>Hi, I have a question regarding to integer addition.
>>>
>>>Here is the problem.
>>>
>>>I have an integer, x = 0x00000001
>>>and I also have another integer, y = 0xffffff94
>>>
>>>Is there any method to concatenate x & y, so that x = 0x00000194 ?
>>>Thanks for the help. =)[/color]
>>
>>So you're looking for a function that takes 2 integers and returns
>>0x00000194 if the input is 0x00000001 and 0xffffff94?
>>
>>int f(int x, int y)
>>{
>> return 0x00000194;
>>}
>>
>>Ok, probably not what you were looking for but it's difficult to create
>>a reasonable function when given only 1 input-output pair...
>>
>>Maybe you want to take the 1 of x and place at infront of the 94 of y?
>>Then the function would look like this (i think):
>> return (x << 8) | (y & 0xFF);[/color]
>
>
> You forgot about the 0xfffff part, which has to be masked away (if
> your theory of what the function should do holds)
>
> return ( (x & ~0xff) << 8 ) | ( y & 0xff );
>[/color]

Don't think so! The 0xffffff was only in y, not in x. Your function
would return 0x00000094 because (x & ~0xff) equals 0

[David Harmon]

Re: wried integer addition

On Fri, 20 Feb 2004 10:08:53 +0100 in comp.lang.c++, Karl Heinz
Buchegger <kbuchegg@gasca d.at> was alleged to have written:[color=blue][color=green]
>> You forgot about the 0xfffff part, which has to be masked away (if
>> your theory of what the function should do holds)
>>
>> return ( (x & ~0xff) << 8 ) | ( y & 0xff );
>>[/color]
>
>
>grr.
>That's the problem with bit operations: It is easy to read something
>into a source code which is not written there.[/color]

Perhaps you would prefer

const int rad = 256;
return (x * rad) + (y % rad);

[Geoffrey Mortimer]

Re: wried integer addition


"tikviva" <tikviva@yahoo. com> wrote in message
news:4b2febc7.0 402192257.baa91 10@posting.goog le.com...[color=blue]
> Hi, I have a question regarding to integer addition.
>
> Here is the problem.
>
> I have an integer, x = 0x00000001
> and I also have another integer, y = 0xffffff94
>
> Is there any method to concatenate x & y, so that x = 0x00000194 ?
> Thanks for the help. =)
>
> God bless,
> tikviva[/color]

Homework?

(x + 1) << 8 + y