Declaring huge Arrays

I declared an array deskone[2600] and got an error "error c2900: huge array cannot be aligned to segment boundary". the error goes away when I reduced the elements in the array to 1900. I need this array to be 2600. how do I declare this without the error. any help is greatly appreciated

If the array has automatic storage duration, it typically will be allocated storage on the stack, which tends to be limited, so declare the array to have static or allocated storage duration instead. To declare the array as having static storage duration, you would either declare it at file scope (in which case it becomes a global variable), or declare it static (in which case it can have local scope, though it retains some maintenance disavantage in being static). For allocated storage duration, you would use malloc and free and do manual memory management.

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Originally Posted by laserlight

If the array has automatic storage duration, it typically will be allocated storage on the stack, which tends to be limited, so declare the array to have static or allocated storage duration instead. To declare the array as having static storage duration, you would either declare it at file scope (in which case it becomes a global variable), or declare it static (in which case it can have local scope, though it retains some maintenance disavantage in being static). For allocated storage duration, you would use malloc and free and do manual memory management.

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Thanks the array is global. I will use malloc

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Originally Posted by John Malloc

Thanks the array is global. I will use malloc

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If the array is global then you don't need to use malloc.

You gave us very little information to go on. You didn't tell us the size of the array elements or where/how you declared it.

I figure that anything which regards 2600 as huge and talks about segments must be some fossil 16-bit compiler from 20 to 30 years ago.

The first question would be why joining the current millennium isn't an option.

thanks everyone. the array is global in a glob.h file.
insert

Code:

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typedef struct
{
float time
float key
.
.
}Key_Type;

originally also declared in same file
extern Key_Type huge key_inputs[2600];
I then declared in another file where key_inputs is used key.c
key_type huge key_inputs[2600];

this worked up to 1900 elements. throws a segmented boundary error at 2600. that hwy I tried to use malloc. Now I have
in glob.h
extern Key_Type key_inputs[2600];
and in key.c I have
key_type key_inputs = (key_type *) malloc(2600 *sizeof (key_type) ;
if (null==key_type)
{
fprintf(stderr, "malloc failed\n");
return (-1);
}

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Now this gives me 2 errors 1 warning
key.c - error c2040: key_inputs different level of indirection
syntax error c2143 missing ";" before if
warning: c4307: "*": integral constant overflow

any help on any of the two way is appreciated. need to get this working for an array of 2600 elements with with huge or malloc. huge worked up to 1900.
thanks

What kind of machine are you programming? Is it 16-bits?

You are still keeping the size of Key_Type a secret for some reason. We can now see that it holds at least 8 bytes. But how f'ing big is it?!

If it's more than 25 bytes then multiplying it by 2600 will overflow an unsigned 16-bit int.

"huge" is not a standard keyword, so I don't really know anything about it.

For the malloc, your extern statement should be:

Code:

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extern Key_Type *key_inputs;

// Then in key.c:

Key_Type *key_inputs = malloc(2600 * sizeof *key_inputs);

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Using Large Arrays In Turbo C | Dr Dobb's
Make a note of the date at the top.

Which compiler are you using? farmalloc might have a different name if you're using some other fossil compiler.
What machine are you running the program on?
What OS is running on that machine?

Quote:

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Originally Posted by Salem

Using Large Arrays In Turbo C | Dr Dobb's
Make a note of the date at the top.

Which compiler are you using? farmalloc might have a different name if you're using some other fossil compiler.
What machine are you running the program on?
What OS is running on that machine?

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its a float array with 17 members. the code is complied in Microsoft C 1.52 compiler. runs under DOS. thanks to everyone who helped

Why is it running on DOS?
DOS became obsolete for desktop computers about 25 years ago.

the number 2600 is the index to the array.

Huh?

2600 is not an index to an array with 2600 elements.

Valid indices run from 0 to 2599 for such an array.

For the old Microsoft huge arrays, if the total array size is greater than 128KB, then element size (in this case Key_Type) needs to be a power of 2 (2,4,8,16, ..., this is due to the way huge (segment : offset) addresses are calculated based on index). This may be the issue. What is the size of Key_Type? I'm guessing it's greater than 50 bytes? If so, pad Key_Type with a dummy member (perhaps call it pad) to make the size of Key_Type 64 bytes or 128 bytes.

The "huge" version of malloc() is halloc(), prototype:

Code:

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void huge *halloc(long n, size_t size);

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