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Re: [RFC] Builtin infrastructure change


On Tue, Oct 4, 2011 at 2:07 AM, Michael Meissner
<meissner@linux.vnet.ibm.com> wrote:
> On Sat, Oct 01, 2011 at 02:11:27PM +0000, Joseph S. Myers wrote:
>> On Fri, 30 Sep 2011, Michael Meissner wrote:
>>
>> > Is this enough of a savings to continue on? ?I'm of two minds about it, one is
>>
>> The thing to measure is not so much memory as startup time (how long it
>> takes to compile an empty source file), which is important for libraries
>> and programs using a coding style with lots of small source files.
>
> With my current changes which has modified the standard builtins to be lazy,
> but I haven't yet done the machine dependent builtins, I saw a difference of
> 0.0022 seconds (0.0170 vs. 0.0148) on my 3 year old Intel core 2 laptop. ?I did
> 14 runs in total, and skipped the fastest 2 runs and slowest 2 runs, and then
> averaged the 10 runs in the middle. ?I built boostrap builds with release
> checking with the top of subversion head without changes and with my changes.
>
> So at this point, I'm wondering whether it is worth it to finish the
> optimization for lazy builtins.

I think it is.

+/* Return the tree node for a builtin function or NULL, indexing into the
+   array.  */
+static inline tree
+built_in_set_decl_add (enum built_in_function fncode, int addend)
+{
+  return built_in_decls ((enum built_in_function)(((int)fncode) + addend));
+}

this doesn't seem to "set" anything.  Mistake?

+static inline tree
+built_in_decls (enum built_in_function fncode)

I'd prefer singular, built_in_decl () instead of plural.

+static inline tree
+implicit_built_in_decls (enum built_in_function fncode)

Likewise.

+/* Initialize an implicit builtin function.  */
+static inline void
+built_in_set_implicit (enum built_in_function fncode, tree implicit)

and built_in_set_implicit_decl (or rather set_implicit_built_in_decl - hm,
I guess I'm now bikeshedding ;)).

The patch is ok with the built_in_set_decl_add mystery resolved
(I'd best not have the function at all but perform the ugly add and casting
in the few callers -- it _is_ ugly to do that after all, so it might as well
look so ;)).

It would be nice to use singular/plural consistently (different currently
for set and get, I prefer singular).  The rest of the bikeshedding - oh well ;)

Thanks,
Richard.

> --
> Michael Meissner, IBM
> 5 Technology Place Drive, M/S 2757, Westford, MA 01886-3141, USA
> meissner@linux.vnet.ibm.com ? ? fax +1 (978) 399-6899
>


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