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Date: Mon, 01 Aug 2016 11:33:00 -0000
From: Richard Biener <rguenther@suse.de>
To: Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>
cc: gcc Patches <gcc-patches@gcc.gnu.org>
Subject: Re: fold strlen (s) eq/ne 0 to *s eq/ne 0 on GIMPLE
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On Mon, 1 Aug 2016, Prathamesh Kulkarni wrote:

> Hi Richard,
> The attached patch tries to fold strlen (s) eq/ne 0 to *s eq/ne 0 on GIMPLE.
> I am not sure where was the ideal place to put this transform in and ended up
> adding it to strlen_optimize_stmt().
> Does that look OK ?
> 
> I needed to add TODO_update_ssa to strlen pass, otherwise we hit the
> following assert in execute_todo():
> if (flag_checking
>       && cfun
>       && need_ssa_update_p (cfun))
>     gcc_assert (flags & TODO_update_ssa_any);
> 
> Bootstrap+test in progress on x86_64-unknown-linux-gnu.

I believe you should factor small-size part of handle_builtin_memcmp and
re-use that for the code generation part.

You should also remove the corresponding fold-const.c code I think.

Richard.