Q41094: Huge Arrays Not Allowed in QuickC 2.00, But Huge Pointers Are

Article: Q41094
Product(s): See article
Version(s): 2.00
Operating System(s): MS-DOS
Keyword(s): ENDUSER | SR# G890209-11614 buglist2.00 | mspl13_c
Last Modified: 28-FEB-1989

The program below produces the following errors when compiled with
QuickC Version 2.00, even when using huge-memory model (/AH):

   prog.c(4) : error C2125: a : allocation exceeds 64K
   prog.c(8) : error C2125: b : allocation exceeds 64K

The following is the program:

#include <stdio.h>

short a[64000];

main()
{
static short b[64000];
}

Microsoft has confirmed this to be a problem in Version 2.00. We are
researching this problem and will post new information as it becomes
available.

"Huge support" for QuickC means that we perform proper arithmetic for
huge items. It does not mean that we allow huge items to be
declared -- only pointers to them.

To work around this problem, declare the pointer, then use halloc to
allocate the memory. The pointer will be addressed properly. Note: C
Version 5.10 does allow declarations of huge items.

Below is a sample program that demonstrates the workaround. Once
memory for the array has been allocated, the pointer to the base type
of the array may be treated exactly as you would have treated an
array.

The following is the program:

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>

#define MAX 33000L

unsigned huge *a;

void main(void)
{
unsigned huge *b;
unsigned i;

    a = halloc(MAX, sizeof(unsigned));  /* allocate "global" array */
                /* IMPORTANT--make sure the allocations worked! */
    if (!a) { puts("a is NULL");  exit(1);  }
    b = halloc(MAX, sizeof(unsigned));  /* allocate "local" array */
        if (!b) { puts("b is NULL");  exit(1);  }

    for (i = 0; i < MAX; i++)  {    /* access memory as arrays */
                a[i] = i;
                b[i] = (unsigned)MAX - i - 1;
        }

    for (i = 0; i < MAX; i++)  {    /* check to make sure it's OK */
                if (a[i] != i)  {
                        printf("a[%u] is %u rather than %u\n",
                                i, a[i], i);
                        exit(2);
                }
                if (b[i] != (unsigned)MAX - i -1)  {
                        printf("b[%u] is %u rather than %u\n",
                                i, b[i], (unsigned)MAX - i -1);
                        exit(2);
                }
        }
        puts("Test passed");
        exit(0);
}

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