return 0;
/* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
- for neither. Then compute our result treating them as never equal
- and comparing bounds to non-bounds as above. */
+ for neither. In real maths, we cannot assume open ended ranges are
+ the same. But, this is computer arithmetic, where numbers are finite.
+ We can therefore make the transformation of any unbounded range with
+ the value Z, Z being greater than any representable number. This permits
+ us to treat unbounded ranges as equal. */
sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
switch (code)
{
- case EQ_EXPR: case NE_EXPR:
- result = (code == NE_EXPR);
+ case EQ_EXPR:
+ result = sgn0 == sgn1;
+ break;
+ case NE_EXPR:
+ result = sgn0 != sgn1;
break;
- case LT_EXPR: case LE_EXPR:
+ case LT_EXPR:
result = sgn0 < sgn1;
break;
- case GT_EXPR: case GE_EXPR:
+ case LE_EXPR:
+ result = sgn0 <= sgn1;
+ break;
+ case GT_EXPR:
result = sgn0 > sgn1;
break;
+ case GE_EXPR:
+ result = sgn0 >= sgn1;
+ break;
default:
abort ();
}