Eric Botcazou <ebotca...@adacore.com> writes:
>> Index: gcc/tree.c
>> ===================================================================
>> --- gcc/tree.c 2019-01-04 11:39:24.810266962 +0000
>> +++ gcc/tree.c 2019-01-04 11:40:33.141683783 +0000
>> @@ -11229,6 +11229,60 @@ initializer_zerop (const_tree init, bool
>> }
>> }
>>
>> +/* Return true if EXPR is an initializer expression that consists only
>> + of INTEGER_CSTs for which IP0 or IP1 holds and REAL_CSTs for which
>> + RP0 or RP1 holds. The choice between IP0 and IP1, and between
>> + RP0 and RP1, can vary from one element to the next. */
>> +
>> +template<bool (*IP0) (const_tree), bool (*IP1) (const_tree),
>> + bool (*RP0) (const_tree), bool (*RP1) (const_tree)>
>> +bool
>> +initializer_each_a_or_bp (const_tree expr)
>> +{
>> +#define RECURSE(X) initializer_each_a_or_bp<IP0, IP1, RP0, RP1> (X)
>> +
>> + STRIP_ANY_LOCATION_WRAPPER (expr);
>> +
>> + switch (TREE_CODE (expr))
>> + {
>> + case INTEGER_CST:
>> + return IP0 (expr) || IP1 (expr);
>> +
>> + case REAL_CST:
>> + return RP0 (expr) || RP1 (expr);
>> +
>> + case VECTOR_CST:
>> + {
>> + unsigned HOST_WIDE_INT nelts = vector_cst_encoded_nelts (expr);
>> + if (VECTOR_CST_STEPPED_P (expr)
>> + && !TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr)).is_constant (&nelts))
>> + return false;
>> +
>> + for (unsigned int i = 0; i < nelts; ++i)
>> + if (!RECURSE (VECTOR_CST_ENCODED_ELT (expr, i)))
>> + return false;
>> +
>> + return true;
>> + }
>> +
>> + default:
>> + return false;
>> + }
>> +
>> +#undef RECURSE
>
> Can we avoid the gratuitous use of template here? We were told that C++
> would
> be used only when it makes things more straightforward and it's the contrary
> in this case, to wit the need for the ugly RECURSE macro in the middle.
I did it that way so that it would be easy to add things like
zero_or_minus_onep without cut-&-pasting the whole structure.
The way to do that in C would be to use a macro for the full
function, but that's even uglier due to the extra backslashes.
I can change it to:
for (unsigned int i = 0; i < nelts; ++i)
{
tree elt = VECTOR_CST_ENCODED_ELT (expr, i);
if (!initializer_each_a_or_bp<IP0, IP1, RP0, RP1> (elt))
return false;
}
if we want to avoid macros.
I was actually worried that this wouldn't be C++ enough, due to not
using a function template to combine each pair of functions. :-)
Richard
