private static Stamp narrowingKindConvertion(IntegerStamp fromStamp, Kind toKind) {
long mask = fromStamp.mask() & IntegerStamp.defaultMask(toKind);
long lowerBound = saturate(fromStamp.lowerBound(), toKind);
long upperBound = saturate(fromStamp.upperBound(), toKind);
if (fromStamp.lowerBound() < toKind.getMinValue()) {
upperBound = toKind.getMaxValue();
}
if (fromStamp.upperBound() > toKind.getMaxValue()) {
lowerBound = toKind.getMinValue();
}
return StampFactory.forInteger(toKind.getStackKind(), lowerBound, upperBound, mask);
}
public static long saturate(long v, Kind kind) {
long max = kind.getMaxValue();
if (v > max) {
return max;
}
long min = kind.getMinValue();
if (v < min) {
return min;
}
return v;
}
public static Stamp negate(Stamp stamp) {
Kind kind = stamp.kind();
if (stamp instanceof IntegerStamp) {
IntegerStamp integerStamp = (IntegerStamp) stamp;
if (integerStamp.lowerBound() != kind.getMinValue()) {
// TODO(ls) check if the mask calculation is correct...
return new IntegerStamp(
kind,
-integerStamp.upperBound(),
-integerStamp.lowerBound(),
IntegerStamp.defaultMask(kind) & (integerStamp.mask() | -integerStamp.mask()));
}
}
return StampFactory.forKind(kind);
}