memory use global vs auto

[ok]

I have the following code:

void foo(void)
{
const int array[100] = ....;

// do stuff with array
}

I mostly use code like this so my program doesnt waste memory because array
only gets allocated when foo is called.
But now I heard from somebody that the following code is the same in terms
of memory footprint:

static int array[100] = .....

void foo(void)
{
// do stuff with array
}

is that true?

[Ben Pfaff]

"ok" <[e-mail]> writes:

[question about comparative memory footprint of two examples
below]

void foo(void)
{
const int array[100] = ....;

// do stuff with array
} static int array[100] = .....

I imagine that these would have approximately the same memory
footprint on many implementations, given that the former array is
const. If it was non-const, then it would likely take *more*
memory than the latter, because the implementation would likely
initialize the array by copying a statically allocated copy.
--
"Give me a couple of years and a large research grant,
and I'll give you a receipt." --Richard Heathfield

[Christian Bau]

In article <du**********@news5.zwoll1.ov.home.nl>, "ok" <[e-mail]>
wrote:

I have the following code:

void foo(void)
{
const int array[100] = ....;

// do stuff with array
}

I mostly use code like this so my program doesnt waste memory because array
only gets allocated when foo is called.

Think for ten minutes what kind of code your compiler would have to
produce to implement this. Then have a look at the assembler code that
it generates. It will be a good learning experience.

[Nils O. Selåsdal]

ok wrote:

I have the following code:

void foo(void)
{
const int array[100] = ....;

// do stuff with array
}

I mostly use code like this so my program doesnt waste memory because array
only gets allocated when foo is called.
But now I heard from somebody that the following code is the same in terms
of memory footprint:

static int array[100] = .....

void foo(void)
{
// do stuff with array
}

is that true?

That is entierly up to the implementation (your particular compiler),
possibly also which optimizations you enable, etc., too.

[ok]

"Christian Bau" <ch***********@cbau.freeserve.co.uk> wrote in message
news:ch*********************************@slb-newsm1.svr.pol.co.uk...

In article <du**********@news5.zwoll1.ov.home.nl>, "ok" <[e-mail]>
wrote:

I have the following code:

void foo(void)
{
const int array[100] = ....;

// do stuff with array
}

I mostly use code like this so my program doesnt waste memory because
array
only gets allocated when foo is called.

Think for ten minutes what kind of code your compiler would have to
produce to implement this. Then have a look at the assembler code that
it generates. It will be a good learning experience.

will do, installing my fav compiler now :)
So I guess it doesnt matter to use global static or auto in this case
mostly?