Function fxSumEntry

xs/sources/xsMapSet.c:1282–1340

}

txU4 fxSumEntry(txMachine* the, txSlot* slot) 
{
	txU1 kind = slot->kind;
	txU8 sum;
	
	if ((XS_STRING_KIND == kind) || (XS_STRING_X_KIND == kind)) {
		// Dan Bernstein: http://www.cse.yorku.ca/~oz/hash.html
		txU1 *string = (txU1*)slot->value.string;
		sum = 5381;
		while ((kind = c_read8(string++))) {
			sum = ((sum << 5) + sum) + kind;
		}
	}
	else {
		if (XS_REFERENCE_KIND == kind) {
			sum = (txU8)(((uintptr_t)slot->value.reference) / sizeof(txSlot));
		}
		else if (XS_INTEGER_KIND == kind) {
			fxToNumber(the, slot);
			sum = *((txU8*)&slot->value.number);
		}
		else if (XS_NUMBER_KIND == kind) {
			if (slot->value.number == 0) {
				sum = slot->value.number = 0;
			}
			else {
				if (c_isnan(slot->value.number)) {
				#if mxCanonicalNaN
					slot->value.number = *gxCanonicalNaN64;
				#else				
					slot->value.number = C_NAN;
				#endif
				}
				sum = *((txU8*)&slot->value.number);
			}
		}
		else if ((XS_BIGINT_KIND == kind) || (XS_BIGINT_X_KIND == kind)) {
			sum = gxTypeBigInt.toBigUint64(the, slot);
		}
		else if (XS_SYMBOL_KIND == kind) {
			sum = slot->value.symbol;
		}
		else if (XS_BOOLEAN_KIND == kind) {
			sum = slot->value.boolean;
		}
		else {
			sum = 0;
		}
		// Thomas Wang: http://web.archive.org/web/20071223173210/http://www.concentric.net/~Ttwang/tech/inthash.htm
		sum = (~sum) + (sum << 18); // sum = (sum << 18) - sum - 1;
		sum = sum ^ (sum >> 31);
		sum = sum * 21; // sum = (sum + (sum << 2)) + (sum << 4);
		sum = sum ^ (sum >> 11);
		sum = sum + (sum << 6);
		sum = sum ^ (sum >> 22);
	}
	sum &= 0xFFFFFFFF;
	return (txU4)sum;