On Jan 14, 2014, at 7:25 AM, Richard Sandiford <rsand...@linux.vnet.ibm.com>
wrote:
> Mike Stump <mikest...@comcast.net> writes:
>> diff --git a/gcc/expmed.c b/gcc/expmed.c
>> index ce063eb..720d8c1 100644
>> --- a/gcc/expmed.c
>> +++ b/gcc/expmed.c
>> @@ -4963,6 +4963,7 @@ make_tree (tree type, rtx x)
>> return t;
>>
>> case CONST_DOUBLE:
>> + gcc_assert (HOST_BITS_PER_WIDE_INT * 2 <= MAX_BITSIZE_MODE_ANY_INT);
>> if (TARGET_SUPPORTS_WIDE_INT == 0 && GET_MODE (x) == VOIDmode)
>> t = wide_int_to_tree (type,
>> wide_int::from_array (&CONST_DOUBLE_LOW (x), 2,
>
> I think this would be better as a STATIC_ASSERT.
The cost should be the same in generated code. The C folks can read and
understand the gcc_assert easier, and the static property of the check we don't
make any use of. I could change it, but there are 0 of these in *.c presently,
and I think we want to tread lightly on those folks that know and like C, and
don't want gcc to be `different' for no good reason. That said, if people
think it would be good to use it, I'd be happy to change it.
>> @@ -1440,10 +1442,10 @@ real_to_integer (const REAL_VALUE_TYPE *r, bool
>> *fail, int precision)
>> }
>> #endif
>> w = SIGSZ * HOST_BITS_PER_LONG + words * HOST_BITS_PER_WIDE_INT;
>> - result = wide_int::from_array
>> + tmp = real_int::from_array
>> (val, (w + HOST_BITS_PER_WIDE_INT - 1) / HOST_BITS_PER_WIDE_INT, w);
>> - result = wi::lrshift (result, (words * HOST_BITS_PER_WIDE_INT) - exp);
>> - result = wide_int::from (result, precision, UNSIGNED);
>> + tmp = wi::lrshift<real_int> (tmp, (words * HOST_BITS_PER_WIDE_INT) -
>> exp);
>> + result = wide_int::from (tmp, precision, UNSIGNED);
>
> Why did you need the <real_int>? It was supposed to work without.
The code in question needs something that is max int + max significand real in
size, we made the max int smaller (smaller than this quantity on x86) so, this
code needs a special wide int that is bigger. The type is free as vrp uses the
same type. As for why Kenny choose this method, I'd defer to him.
>> diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
>> index 00b5439..7c21afa 100644
>> --- a/gcc/simplify-rtx.c
>> +++ b/gcc/simplify-rtx.c
>> @@ -5384,6 +5384,7 @@ simplify_immed_subreg (enum machine_mode outermode,
>> rtx op,
>> tmp[u] = buf;
>> base += HOST_BITS_PER_WIDE_INT;
>> }
>> + gcc_assert (GET_MODE_PRECISION (outer_submode) <=
>> MAX_BITSIZE_MODE_ANY_INT);
>> r = wide_int::from_array (tmp, units,
>> GET_MODE_PRECISION (outer_submode));
>> elems[elem] = immed_wide_int_const (r, outer_submode);
>
> Long line.
Fixed:
Index: simplify-rtx.c
===================================================================
--- simplify-rtx.c (revision 206601)
+++ simplify-rtx.c (working copy)
@@ -5384,7 +5384,8 @@ simplify_immed_subreg (enum machine_mode
tmp[u] = buf;
base += HOST_BITS_PER_WIDE_INT;
}
- gcc_assert (GET_MODE_PRECISION (outer_submode) <=
MAX_BITSIZE_MODE_ANY_INT);
+ gcc_assert (GET_MODE_PRECISION (outer_submode)
+ <= MAX_BITSIZE_MODE_ANY_INT);
r = wide_int::from_array (tmp, units,
GET_MODE_PRECISION (outer_submode));
elems[elem] = immed_wide_int_const (r, outer_submode);
Thanks for the review.
