Re: Work around PR65873

[Sandra Loosemore <sandra at codesourcery dot com>]

On 05/12/2015 04:12 PM, Jan Hubicka wrote:
> Hi,
> this patch works around PR where we refuse to inline always_inline memcpy
> into function with explicit Ofast optimization attribute.  This is because
> we think we can not promote -fno-fast-math code to -fast-math code.
> This is of course safe for memcpy because it contains to fast-math code,
> but we don't really do the analysis for each of the flags we check.
>
> Earlier compilers was happily producing wrong code here and it seems practical
> to do that on GCC 5 to deal with common falout.  I will implement the more
> fine grained check incrementally.
>
> Bootstrapped/regtested x86_64-linux. Will commit it to mainline shortly and
> to release branch later this week.
>
> 	PR ipa/65873
> 	* ipa-inline.c (can_inline_edge_p): Allow early inlining of always
> 	inlines across optimization boundary.
> 	* testsuite/gcc.c-torture/compile/pr65873.c: New testcase.
> Index: ipa-inline.c
> ===================================================================
> --- ipa-inline.c	(revision 223093)
> +++ ipa-inline.c	(working copy)
> @@ -427,46 +427,55 @@ can_inline_edge_p (struct cgraph_edge *e
>   	      && lookup_attribute ("always_inline",
>   				   DECL_ATTRIBUTES (callee->decl)));

I'm having problems parsing the following comment block:

> +     /* Until GCC 4.9 we did not check the semantics alterning flags

"alterning"?

> +	bellow and inline across optimization boundry.

s/bellow/below/g
s/boundry/boundary/

> +	Enabling checks bellow breaks several packages by refusing
> +	to inline library always_inline functions. See PR65873.
> +	Disable the check for early inlining for now until better solution
> +	is found.  */
> +     if (always_inline && early)
> +	;

-Sandra