Re: [GD-General] meaning of sizeof(int) on all plateform

[<Lag...@wa...>]

Messageno confusion here,=20
Following suestion here are purelly curiosity:

i precise the question:

if you have a 32 bit architecture (pentium)
if you want make fast arithmetic operation, you
must work with type which have a size of 32bits.
These type have the same size of a register and the
arithmetic operation can be optimize...
typically, this is type "int"

on a 64 bit architecture (itanium)=20
register are 64 bit and int are 64bit too

so if you have a program which perform the following code:

// imaginary define
// the goal of this define is to have s32 on 32bits
#ifdef __32Bit__
typedef int s32
#else // __64bit__
typedef short u32  // just for exemple
#endif

void add(s32 a1, s32 a2)
{
    return a1 + a2;
}

the performance can be poor on a 64bit architecture because we are not
in the native size of the register

if we have this code

void add(int a1, int a2)
{
    return a1 + a2;
}

no problem, cause "int" is native to the architecture

it is my imagination, I'am in the wrong way ?

another question, is sizeof(int) =3D=3D sizeof(void*) ?
sizeof(void*) must be : size of memory bus address
so sizeof(int)....

--------------------------
Lagarde S=E9bsatien
Neko entertainment
Junior programmer
  ----- Original Message -----=20
  From: Mick West=20
  To: gam...@li...=20
  Sent: Thursday, June 26, 2003 8:48 PM
  Subject: RE: [GD-General] meaning of sizeof(int) on all plateform


  128 bits would give you 16 bytes, not 32.

  On the PS2 an int is generally 32 BITS,  (4 bytes), which is maybe =
where the confusion arose.

  Mick
    -----Original Message-----
    From: gam...@li... =
[mailto:gam...@li...] On Behalf Of =
Gareth Lewin
    Sent: Thursday, June 26, 2003 11:42 AM
    To: gam...@li...
    Subject: RE: [GD-General] meaning of sizeof(int) on all plateform


    sizeof(int) =3D size of integer value. As defined by the compiler =
vendor. There is no "Correct" way to set the size of int.
      -----Original Message-----
      From: Lagarde S=E9bastien [mailto:Lag...@wa...]
      Sent: 26 June 2003 19:36
      To: gam...@li...
      Subject: [GD-General] meaning of sizeof(int) on all plateform


      Hello all,=20
      I have some problem to define what represent sizeof(int).

      IMO sizeof(int) =3D=3D memory bus address width

      but on platforme like PS2, you have a bus of 128 and sizeof(int) =
=3D=3D 32.

      i have seen elsewherre that sizeof(int) =3D=3D size of a register.

      Is someone have some information on this point ?
      thanks
      -------------------------------
      Lagarde S=E9bastien
      Neko entertainment
      Junior programmer