bug#24290: ImageMagick optimized for the host processor type on x86_64 and i686

bug#24290: ImageMagick optimized for the host processor type on x86_64 and i686

[Leo Famulari]

When building ImageMagick on i686 and x86_64, the '-mtune' GCC option
[0] is automatically set to optimize the output for the host processor
[1].

My understand of the GCC documentation is that the binaries will still
run on other processor types, which is why we haven't noticed any
related problems with ImageMagick so far.

But, this definitely makes the ImageMagick package non-reproducible.

Potential solutions:

* Set '-mtune=generic' when building on x86_64 and i686.
* Patch the build system to not try setting this flag at all. I'm not
sure how to achieve this, but I'm sure it's possible.
* Your great idea here :)

These are the two files that contain the string '-mtune' in the
ImageMagick source tree:

http://git.imagemagick.org/repos/ImageMagick/blob/ImageMagick-6/m4/ax_gcc_archflag.m4

I recommend *not* opening this file in your browser. It's very long and
might crash your browser. Try cloning the Git repo instead.
hXXp://git.imagemagick.org/repos/ImageMagick/blob/ImageMagick-6/configure

[0]
https://gcc.gnu.org/onlinedocs/gcc-4.9.4/gcc/i386-and-x86-64-Options.html#i386-and-x86-64-Options

[1]
http://hydra.gnu.org/build/1441619/log#line-2626
[...]
checking whether C compiler accepts -mtune=haswell... yes
checking for gcc architecture flag... -mtune=haswell
[...]

bug#24290: [PATCH 0/1] Potential solution

[Leo Famulari]

I found this bug report on a related issue:
https://fedorahosted.org/fesco/ticket/1443

They suggested building with '--without-gcc-arch', and it seems to work
for me. At least, '-mtune' is not mentioned anywhere in the build log.

Leo Famulari (1):
  gnu: imagemagick: Don't build with processor-specific optimizations.

 gnu/packages/imagemagick.scm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.9.3

bug#24290: [PATCH 1/1] gnu: imagemagick: Don't build with processor-specific optimizations.

[Leo Famulari]

* gnu/packages/imagemagick.scm (imagemagick)[arguments]: Pass --without-gcc-arch
to #:configure-flags.
---
 gnu/packages/imagemagick.scm | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gnu/packages/imagemagick.scm b/gnu/packages/imagemagick.scm
index b7054c8..a554b73 100644
--- a/gnu/packages/imagemagick.scm
+++ b/gnu/packages/imagemagick.scm
@@ -51,7 +51,7 @@
                "00arcvyhsy9i5gp3b0lhfvs04qwhxpmq0bfsv4ipllinb6mjgxf5"))))
     (build-system gnu-build-system)
     (arguments
-     `(#:configure-flags '("--with-frozenpaths")
+     `(#:configure-flags '("--with-frozenpaths" "--without-gcc-arch")
        #:phases (modify-phases %standard-phases
                   (add-before
                    'build 'pre-build
-- 
2.9.3

bug#24290: [PATCH 1/1] gnu: imagemagick: Don't build with processor-specific optimizations.

[Eric Bavier]

On Mon, 22 Aug 2016 22:40:02 -0400
Leo Famulari <leo@famulari.name> wrote:

> * gnu/packages/imagemagick.scm (imagemagick)[arguments]: Pass --without-gcc-arch
> to #:configure-flags.
> ---
>  gnu/packages/imagemagick.scm | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gnu/packages/imagemagick.scm b/gnu/packages/imagemagick.scm
> index b7054c8..a554b73 100644
> --- a/gnu/packages/imagemagick.scm
> +++ b/gnu/packages/imagemagick.scm
> @@ -51,7 +51,7 @@
>                 "00arcvyhsy9i5gp3b0lhfvs04qwhxpmq0bfsv4ipllinb6mjgxf5"))))
>      (build-system gnu-build-system)
>      (arguments
> -     `(#:configure-flags '("--with-frozenpaths")
> +     `(#:configure-flags '("--with-frozenpaths" "--without-gcc-arch")
>         #:phases (modify-phases %standard-phases
>                    (add-before
>                     'build 'pre-build

This seems like a good solution to me.  We commonly target SSE2 as a
lcd.  Can we make sure that ImageMagick compiles for SSE2 at least?

`~Eric

bug#24290: [PATCH 1/1] gnu: imagemagick: Don't build with processor-specific optimizations.

[Leo Famulari]

[-- Attachment #1.1: Type: text/plain, Size: 320 bytes --]

On Mon, Aug 22, 2016 at 11:53:52PM -0500, Eric Bavier wrote:
> This seems like a good solution to me.  We commonly target SSE2 as a
> lcd.  Can we make sure that ImageMagick compiles for SSE2 at least?

Sure, but I don't know how to check for that :)

I've attached the log of the configure phase with my patch applied.

[-- Attachment #1.2: imagemagick-configure-log.xz --]
[-- Type: application/octet-stream, Size: 8104 bytes --]

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]

bug#24290: [PATCH 1/1] gnu: imagemagick: Don't build with processor-specific optimizations.

[Leo Famulari]

On Mon, Aug 22, 2016 at 11:53:52PM -0500, Eric Bavier wrote:
> On Mon, 22 Aug 2016 22:40:02 -0400
> Leo Famulari <leo@famulari.name> wrote:
> 
> > * gnu/packages/imagemagick.scm (imagemagick)[arguments]: Pass --without-gcc-arch
> > to #:configure-flags.
> > ---
> >  gnu/packages/imagemagick.scm | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/gnu/packages/imagemagick.scm b/gnu/packages/imagemagick.scm
> > index b7054c8..a554b73 100644
> > --- a/gnu/packages/imagemagick.scm
> > +++ b/gnu/packages/imagemagick.scm
> > @@ -51,7 +51,7 @@
> >                 "00arcvyhsy9i5gp3b0lhfvs04qwhxpmq0bfsv4ipllinb6mjgxf5"))))
> >      (build-system gnu-build-system)
> >      (arguments
> > -     `(#:configure-flags '("--with-frozenpaths")
> > +     `(#:configure-flags '("--with-frozenpaths" "--without-gcc-arch")
> >         #:phases (modify-phases %standard-phases
> >                    (add-before
> >                     'build 'pre-build
> 
> This seems like a good solution to me.  We commonly target SSE2 as a
> lcd.  Can we make sure that ImageMagick compiles for SSE2 at least?

Mark pointed out on IRC that we don't want to assume support for SSE for
our i686 packages, and that SSE/SSE2 is part of the base specification
for x86_64.

So, I pushed this patch as 00831624, and I'm not going to do anything
related to SSE.