- /* We clear out all bits that don't belong in MODE, unless they and
- our sign bit are all one. So we get either a reasonable negative
- value or a reasonable unsigned value for this mode. */
- width = GET_MODE_BITSIZE (mode);
- if (width < HOST_BITS_PER_WIDE_INT
- && ((i0 & ((HOST_WIDE_INT) (-1) << (width - 1)))
- != ((HOST_WIDE_INT) (-1) << (width - 1))))
- i0 &= ((HOST_WIDE_INT) 1 << width) - 1, i1 = 0;
- else if (width == HOST_BITS_PER_WIDE_INT
- && ! (i1 == ~0 && i0 < 0))
- i1 = 0;
- else
- /* We should be able to represent this value as a constant. */
- gcc_assert (width <= 2 * HOST_BITS_PER_WIDE_INT);
-
- /* If this would be an entire word for the target, but is not for
- the host, then sign-extend on the host so that the number will
- look the same way on the host that it would on the target.
-
- For example, when building a 64 bit alpha hosted 32 bit sparc
- targeted compiler, then we want the 32 bit unsigned value -1 to be
- represented as a 64 bit value -1, and not as 0x00000000ffffffff.
- The latter confuses the sparc backend. */
-
- if (width < HOST_BITS_PER_WIDE_INT
- && (i0 & ((HOST_WIDE_INT) 1 << (width - 1))))
- i0 |= ((HOST_WIDE_INT) (-1) << width);
-
- /* If MODE fits within HOST_BITS_PER_WIDE_INT, always use a
- CONST_INT.
-
- ??? Strictly speaking, this is wrong if we create a CONST_INT for
- a large unsigned constant with the size of MODE being
- HOST_BITS_PER_WIDE_INT and later try to interpret that constant
- in a wider mode. In that case we will mis-interpret it as a
- negative number.
-
- Unfortunately, the only alternative is to make a CONST_DOUBLE for
- any constant in any mode if it is an unsigned constant larger
- than the maximum signed integer in an int on the host. However,
- doing this will break everyone that always expects to see a
- CONST_INT for SImode and smaller.
-
- We have always been making CONST_INTs in this case, so nothing
- new is being broken. */
-
- if (width <= HOST_BITS_PER_WIDE_INT)
- i1 = (i0 < 0) ? ~(HOST_WIDE_INT) 0 : 0;