Re: [PATCH] fix size_estimation for builtin_expect

[Rong Xu <xur at google dot com>]

attached the new patch. OK for check in?

On Wed, Oct 2, 2013 at 9:12 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> > Hi,
>> >
>> > builtin_expect should be a NOP in size_estimation. Indeed, the call
>> > stmt itself is 0 weight in size and time. But it may introduce
>> > an extra relation expr which has non-zero size/time. The end result
>> > is: for w/ and w/o builtin_expect, we have different size/time estimation
>> > for inlining.
>> >
>> > This patch fixes this problem.
>> >
>> > An earlier discussion of this patch is
>> >   https://mail.google.com/mail/u/0/?pli=1#label/gcc-paches/1415c590ad8c5315
>> >
>> > This new patch address Honza's comments.
>> > It passes the bootstrap and regression.
>> >
>> > Richard: I looked at your tree-ssa.c:walk_use_def_chains() code. I think
>> > that's an overkill for this simple problem. Your code is mostly dealing
>> > with the recursively walk the PHI node to find the real def stmts.
>> > Here the traversal is within one BB and I may need to continue on multiple
>> > real assignment. Calling walk_use_def_chains probably only uses
>> > the SSA_NAME_DEF_STMT() part of the code.
>> >
>> > Thanks,
>> >
>> > -Rong
>
> This patch is OK.  Add white space after
> +          bool match = false;
> +          bool done = false;
>
> and fix
> +          if (match && single_imm_use (var, &use_p, &use_stmt) &&
> +              (gimple_code (use_stmt) == GIMPLE_COND))
>
> && should be at beggining of new line..
>
> Thanks,
> Honza

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