[PATCH]: initialize dconsts lazily, improve GCC startup time

[Kaveh R. Ghazi]

From: "Richard Guenther" <richard.guenther@gmail.com>

> Ok with one change:
>
>>  @@ -8244,7 +8251,7 @@ fold_builtin_logarithm (tree fndecl, tre
>>           CASE_FLT_FN (BUILT_IN_EXP10):
>>           CASE_FLT_FN (BUILT_IN_POW10):
>>             /* Prepare to do logN(exp10(exponent) -> exponent*logN(10). 
>> */
>>  -           x = build_real (type, dconst10);
>>  +           x = build_real_from_int_cst (type, build_int_cst (NULL_TREE, 
>> 10));
>>             exponent = CALL_EXPR_ARG (arg, 0);
>>             break;
>>           CASE_FLT_FN (BUILT_IN_SQRT):
>
> Please use build_real_from_int here to avoid build_int_cst with a NULL 
> type.
> Richard.

Um, I don't see any such function in GCC.  I tried looking for one before I 
submitted my patch and didn't find anything that goes directly from 10 to a 
"real" tree.  Perhaps it has another name?

        --Kaveh
--
Kaveh R. Ghazi