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 Stamp leftShift(IntegerStamp value, IntegerStamp shift) {
Kind kind = value.kind();
int shiftBits = kind == Kind.Int ? 5 : 6;
long shiftMask = kind == Kind.Int ? 0x1FL : 0x3FL;
if ((shift.lowerBound() >>> shiftBits) == (shift.upperBound() >>> shiftBits)) {
long mask = 0;
for (long i = shift.lowerBound() & shiftMask; i <= (shift.upperBound() & shiftMask); i++) {
mask |= value.mask() << i;
}
mask &= IntegerStamp.defaultMask(kind);
return stampForMask(kind, mask);
}
return StampFactory.forKind(kind);
}
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);
}
public static Stamp unsignedRightShift(IntegerStamp value, IntegerStamp shift) {
Kind kind = value.kind();
if (shift.lowerBound() == shift.upperBound()) {
long shiftMask = kind == Kind.Int ? 0x1FL : 0x3FL;
long shiftCount = shift.lowerBound() & shiftMask;
if (shiftCount != 0) {
long lowerBound;
long upperBound;
if (value.lowerBound() < 0) {
lowerBound = 0;
upperBound = IntegerStamp.defaultMask(kind) >>> shiftCount;
} else {
lowerBound = value.lowerBound() >>> shiftCount;
upperBound = value.upperBound() >>> shiftCount;
}
long mask = value.mask() >>> shiftCount;
return StampFactory.forInteger(kind, lowerBound, upperBound, mask);
}
}
long mask = IntegerStamp.maskFor(kind, value.lowerBound(), value.upperBound());
return stampForMask(kind, mask);
}