[tree-ssa] dead const/pure/alloca call removal

[Jason Merrill]

On Sat, 08 Nov 2003 10:55:16 -0800, "Zack Weinberg" <zack@codesourcery.com> wrote:

> Falk Hueffner <falk.hueffner@student.uni-tuebingen.de> writes:
>
>> Jan Hubicka <jh@suse.cz> writes:
>>
>>> + /* Return false when CALL can be removed when it's return value is dead.
>>               ^ true?
>>
>> I would formulate it like this:
>>
>> Return true if CALL can be removed in case its return value is dead.
>
> Still better English, given your explanation of the return value:
>
>   Return true if CALL cannot be removed even if its return value
>   is dead (i.e. CALL must be assumed to have side effects).

We have a flag for this: TREE_SIDE_EFFECTS, which is cleared in
gimplify_call_expr for const functions.  If it should also be cleared for
pure and alloca calls, please make the change there rather than introduce a
new function.

Jason