From: Sam Ravnborg <sam@ravnborg.org>
To: Joseph Myers <joseph@codesourcery.com>
Cc: libc-alpha@sourceware.org
Subject: Re: Fix powerpc ifunc-sel.h build for -Os
Date: Tue, 27 Feb 2018 20:34:00 -0000 [thread overview]
Message-ID: <20180227180834.GA3300@ravnborg.org> (raw)
In-Reply-To: <alpine.DEB.2.20.1802271756170.14335@digraph.polyomino.org.uk>
Hi Joseph.
On Tue, Feb 27, 2018 at 05:56:46PM +0000, Joseph Myers wrote:
> Compiling the testsuite for powerpc (multi-arch configurations) with
> -Os with GCC 7 fails with:
>
> In file included from ifuncmod1.c:7:0,
> from ifuncdep1.c:3:
> ../sysdeps/powerpc/ifunc-sel.h: In function 'ifunc_sel':
> ../sysdeps/powerpc/ifunc-sel.h:12:3: error: asm operand 2 probably doesn't match constraints [-Werror]
> __asm__ ("mflr 12\n\t"
> ^~~~~~~
> ../sysdeps/powerpc/ifunc-sel.h:12:3: error: asm operand 3 probably doesn't match constraints [-Werror]
> ../sysdeps/powerpc/ifunc-sel.h:12:3: error: asm operand 4 probably doesn't match constraints [-Werror]
> ../sysdeps/powerpc/ifunc-sel.h:12:3: error: impossible constraint in 'asm'
>
> The "i" constraints on function pointers require the function call to
> be inlined so the compiler can see the constant function pointer
> arguments passed to the asm. This patch marks the relevant functions
> as always_inline accordingly.
>
> Tested that this fixes the -Os testsuite build for
> powerpc-linux-gnu-power4, powerpc64-linux-gnu, powerpc64le-linux-gnu
> with build-many-glibcs.py.
>
> 2018-02-27 Joseph Myers <joseph@codesourcery.com>
>
> * sysdeps/powerpc/ifunc-sel.h (ifunc_sel): Make always_inline.
> (ifunc_one): Likewise.
>
> diff --git a/sysdeps/powerpc/ifunc-sel.h b/sysdeps/powerpc/ifunc-sel.h
> index bdb00bf..7112bed 100644
> --- a/sysdeps/powerpc/ifunc-sel.h
> +++ b/sysdeps/powerpc/ifunc-sel.h
> @@ -4,7 +4,7 @@
>
> extern int global;
>
> -static inline void *
> +static inline __attribute__ ((always_inline)) void *
> inhibit_stack_protector
It would be a little less verbose to use __always_inline from cdefs.h
Note: I did not check if this is not feasible for some reasons
> ifunc_sel (int (*f1) (void), int (*f2) (void), int (*f3) (void))
> {
> @@ -32,7 +32,7 @@ ifunc_sel (int (*f1) (void), int (*f2) (void), int (*f3) (void))
> return ret;
> }
>
> -static inline void *
> +static inline __attribute__ ((always_inline)) void *
> inhibit_stack_protector
Same goes here.
Sam
next prev parent reply other threads:[~2018-02-27 18:08 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-27 18:16 Joseph Myers
2018-02-27 20:34 ` Sam Ravnborg [this message]
2018-02-27 20:34 ` Joseph Myers
2018-03-02 22:21 ` Tulio Magno Quites Machado Filho
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