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Re: Unreviewed patch to tree-ssa-loop-ivopts.c
- From: Richard Sandiford <rsandifo at redhat dot com>
- To: Paul Schlie <schlie at comcast dot net>
- Cc: Kazu Hirata <kazu at cs dot umass dot edu>, <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 04 Apr 2005 13:37:36 +0100
- Subject: Re: Unreviewed patch to tree-ssa-loop-ivopts.c
- References: <BE76AC93.9B22%schlie@comcast.net>
Paul Schlie <schlie@comcast.net> writes:
>> From: Richard Sandiford <rsandifo@redhat.com>
>>> Paul Schlie <schlie@comcast.net> writes:
>>> Sorry if I've missed it, where is where does BITS_PER_UNIT define the root
>>> size of all target modes? (i.e. where is a UNIT hard equated with QImode?)
>>>
>>> I've searched all the sources, and can't find any relationship established
>>> between BITS_PER_UNIT any mode definitions anywhere,
>>
>> See genmodes.c:emit_mode_precision. The definitions of the modes
>> themselves are in machmode.def:
>>
>> INT_MODE (QI, 1);
>> INT_MODE (HI, 2);
>> INT_MODE (SI, 4);
>>
>> where the second argument is the number of bytes (i.e. number of units).
>
> Unfortunaly all I see is a definition of their relative sizes,
Are we looking at the same sources?
static void
emit_mode_precision (void)
{
int c;
struct mode_data *m;
print_decl ("unsigned short", "mode_precision", "NUM_MACHINE_MODES");
for_all_modes (c, m)
if (m->precision != (unsigned int)-1)
tagged_printf ("%u", m->precision, m->name);
else
tagged_printf ("%u*BITS_PER_UNIT", m->bytesize, m->name);
---------------------^^^^^^^^^^^^^^^^^
print_closer ();
}
Richard