Hi Joseph and Gaius,
on 2024/6/4 02:02, Joseph Myers wrote:
> On Sun, 2 Jun 2024, Kewen Lin wrote:
>
>> diff --git a/gcc/m2/gm2-gcc/m2type.cc b/gcc/m2/gm2-gcc/m2type.cc
>> index 571923c08ef..d52cbdf0b99 100644
>> --- a/gcc/m2/gm2-gcc/m2type.cc
>> +++ b/gcc/m2/gm2-gcc/m2type.cc
>> @@ -1420,7 +1420,7 @@ build_m2_short_real_node (void)
>> /* Define `REAL'. */
>>
>> c = make_node (REAL_TYPE);
>> - TYPE_PRECISION (c) = FLOAT_TYPE_SIZE;
>> + TYPE_PRECISION (c) = TYPE_PRECISION (float_type_node);
>> layout_type (c);
>> return c;
>> }
>> @@ -1433,7 +1433,7 @@ build_m2_real_node (void)
>> /* Define `REAL'. */
>>
>> c = make_node (REAL_TYPE);
>> - TYPE_PRECISION (c) = DOUBLE_TYPE_SIZE;
>> + TYPE_PRECISION (c) = TYPE_PRECISION (double_type_node);
>> layout_type (c);
>> return c;
>> }
>> @@ -1447,7 +1447,7 @@ build_m2_long_real_node (void)
>> if (M2Options_GetIBMLongDouble ())
>> {
>> longreal = make_node (REAL_TYPE);
>> - TYPE_PRECISION (longreal) = LONG_DOUBLE_TYPE_SIZE;
>> + TYPE_PRECISION (longreal) = TYPE_PRECISION (long_double_type_node);
>
> This looks rather like m2 would still have the same problem the generic
> code previously had: going via precision when that might not uniquely
> determine the desired machine mode. And so making sure to use the right
> machine mode as done when setting up long_double_type_node etc. would be
> better than keeping this code copying TYPE_PRECISION and hoping to
> determine a machine mode from that. It certainly looks like this code
> wants to match float, double and long double, rather than possibly getting
> a different mode with possibly the same TYPE_PRECISION.
Good point, sorry that I just did a replacement without checking the context.
If the above holds (Gaius can confirm or clarify), SET_TYPE_MODE would be
also applied here, that is:
diff --git a/gcc/m2/gm2-gcc/m2type.cc b/gcc/m2/gm2-gcc/m2type.cc
index d52cbdf0b99..5ff02a18876 100644
--- a/gcc/m2/gm2-gcc/m2type.cc
+++ b/gcc/m2/gm2-gcc/m2type.cc
@@ -1421,6 +1421,7 @@ build_m2_short_real_node (void)
c = make_node (REAL_TYPE);
TYPE_PRECISION (c) = TYPE_PRECISION (float_type_node);
+ SET_TYPE_MODE (c, TYPE_MODE (float_type_node));
layout_type (c);
return c;
}
@@ -1434,6 +1435,7 @@ build_m2_real_node (void)
c = make_node (REAL_TYPE);
TYPE_PRECISION (c) = TYPE_PRECISION (double_type_node);
+ SET_TYPE_MODE (c, TYPE_MODE (double_type_node));
layout_type (c);
return c;
}
I'm not sure and curious why the above builds new nodes for short real and
real but re-use float128_type_node or long_double_type_node for some cases,
some special needs cause the former ones should have separated nodes?
>
> (I don't know if the M2Options_GetIBMLongDouble call would be needed at
> all once you use the machine mode for long double in a reliable way, or
> whether this code could be further simplified.)
long_double_type_node should already take care of ibmlongdouble, IIUC it
would be like:
@@ -1443,13 +1445,7 @@ build_m2_long_real_node (void)
{
tree longreal;
- /* Define `LONGREAL'. */
- if (M2Options_GetIBMLongDouble ())
- {
- longreal = make_node (REAL_TYPE);
- TYPE_PRECISION (longreal) = TYPE_PRECISION (long_double_type_node);
- }
- else if (M2Options_GetIEEELongDouble ())
+ if (M2Options_GetIEEELongDouble ())
longreal = float128_type_node;
else
longreal = long_double_type_node;
unless there is some special need requiring one different node for
ibmlongdouble, then:
diff --git a/gcc/m2/gm2-gcc/m2type.cc b/gcc/m2/gm2-gcc/m2type.cc
index c808e3e8dbb..5e479e4bbce 100644
--- a/gcc/m2/gm2-gcc/m2type.cc
+++ b/gcc/m2/gm2-gcc/m2type.cc
@@ -1450,6 +1450,7 @@ build_m2_long_real_node (void)
{
longreal = make_node (REAL_TYPE);
TYPE_PRECISION (longreal) = TYPE_PRECISION (long_double_type_node);
+ SET_TYPE_MODE (longreal, TYPE_MODE (long_double_type_node));
}
else if (M2Options_GetIEEELongDouble ())
longreal = float128_type_node;
BR,
Kewen
