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(simplify_unary_operation): Sign-extend constants when they have the most significant bit set for the target. 

(simplify_unary_operation): Sign-extend constants when
they have the most significant bit set for the target.
(simplify_binary_operation): Likewise.

From-SVN: r9309
This commit is contained in:
Torbjorn Granlund 1995-04-03 23:19:02 +00:00
parent 2e14370ed4
commit ad89d6f68a
1 changed files with 26 additions and 0 deletions
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26
gcc/cse.c
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@ -3266,6 +3266,19 @@ simplify_unary_operation (code, mode, op, op_mode)
!= ((HOST_WIDE_INT) (-1) << (width - 1))))
val &= ((HOST_WIDE_INT) 1 << width) - 1;
/* 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 later confuses the sparc backend. */
if (BITS_PER_WORD < HOST_BITS_PER_WIDE_INT && BITS_PER_WORD == width
&& (val & ((HOST_WIDE_INT) 1 << (width - 1))))
val |= ((HOST_WIDE_INT) (-1) << width);
return GEN_INT (val);
}
#endif
@ -4126,6 +4139,19 @@ simplify_binary_operation (code, mode, op0, op1)
!= ((HOST_WIDE_INT) (-1) << (width - 1))))
val &= ((HOST_WIDE_INT) 1 << width) - 1;
/* 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 later confuses the sparc backend. */
if (BITS_PER_WORD < HOST_BITS_PER_WIDE_INT && BITS_PER_WORD == width
&& (val & ((HOST_WIDE_INT) 1 << (width - 1))))
val |= ((HOST_WIDE_INT) (-1) << width);
return GEN_INT (val);
}