hugemove.c

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/*
 *  Overlap-safe huge memory copy.
 *
 *  Retail object 0x419A40-0x419C0F (link order; see docs/ORDER.md).
 */
#include "game.h"
 
/* Function start: 0x419A40 */
void CopyHugeMemoryOverlapSafe(void *destination, void *source, int count)
{
    if (count == 0)
        return;
    if (DosFarPtrToNear(source) < DosFarPtrToNear(destination)) {
        destination = DosNearPtrToFar(DosFarPtrToNear(destination) + count);
        source = DosNearPtrToFar(DosFarPtrToNear(source) + count);
        for (;;) {
            if ((count -= 0xffff) > -1) {
                source = DosNearPtrToFar(DosFarPtrToNear(source) - 0xffff);
                destination = DosNearPtrToFar(
                    DosFarPtrToNear(destination) - 0xffff);
                DosMemmove(destination, source, 0xffff);
            } else
                break;
        }
        count += 0xffff;
        source = DosNearPtrToFar(DosFarPtrToNear(source) - count);
        destination = DosNearPtrToFar(DosFarPtrToNear(destination) - count);
        DosMemmove(destination, source, (unsigned int)count);
    } else {
        for (;;) {
            if ((count -= 0xffff) > -1) {
                DosMemmove(destination, source, 0xffff);
                source = DosNearPtrToFar(DosFarPtrToNear(source) + 0xffff);
                destination = DosNearPtrToFar(
                    DosFarPtrToNear(destination) + 0xffff);
            } else
                break;
        }
        count += 0xffff;
        DosMemmove(destination, source, (unsigned int)count);
    }
}