[bug#49569] [PATCH] gnu: Add make-single-arch-llvm procedure.

[bug#49569] [PATCH] gnu: Add make-single-arch-llvm procedure.

[Efraim Flashner]

* gnu/packages/llvm.scm (make-single-arch-llvm): New procedure.
(llvm-native-12, llvm-native): New variables.
---

Using this copy of llvm for packages like mesa will reduce the closure
of those packages. I don't suppose it would work as well for compilers
like rust which use LLVM for compiling and targeting different
architectures.

This drops the size of llvm-12 from 167M to 111M.

 gnu/packages/llvm.scm | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/gnu/packages/llvm.scm b/gnu/packages/llvm.scm
index 575c63c713..35cecdfd84 100644
--- a/gnu/packages/llvm.scm
+++ b/gnu/packages/llvm.scm
@@ -1347,3 +1347,27 @@ LLVM."))))
 (define-public ocaml-llvm-9 (make-ocaml-llvm llvm-9))
 (define-public ocaml-llvm-10 (make-ocaml-llvm llvm-10))
 (define-public ocaml-llvm-11 (make-ocaml-llvm llvm-11))
+
+(define* (make-single-arch-llvm llvm #:optional (system (or (%current-target-system)
+                                                            (%current-system))))
+  (package
+    (inherit llvm)
+    (name (string-append "llvm-for-" (string-downcase
+                                       (system->llvm-target system))))
+    (arguments
+     (substitute-keyword-arguments (package-arguments llvm)
+       ((#:configure-flags cf)
+        `(cons* ,(string-append "-DLLVM_TARGETS_TO_BUILD="
+                                (system->llvm-target system))
+                ,cf))))
+    (synopsis "Compiler with support for a single architecture")))
+
+(define-public llvm-native-12
+  (package
+    (inherit (make-single-arch-llvm llvm-12))
+    (name "llvm-native")))
+
+(define-public llvm-native
+  (package
+    (inherit (make-single-arch-llvm llvm))
+    (name "llvm-native")))

base-commit: 17c8fedc256406047c7a1e8317bc52641c621286
-- 
2.32.0

[bug#49569] [PATCH] gnu: Add make-single-arch-llvm procedure.

[Ludovic Courtès]

Hi,

Efraim Flashner <efraim@flashner.co.il> skribis:

> * gnu/packages/llvm.scm (make-single-arch-llvm): New procedure.
> (llvm-native-12, llvm-native): New variables.
> ---
>
> Using this copy of llvm for packages like mesa will reduce the closure
> of those packages. I don't suppose it would work as well for compilers
> like rust which use LLVM for compiling and targeting different
> architectures.
>
> This drops the size of llvm-12 from 167M to 111M.

That’s less impressive than I would have thought.

For Mesa perhaps we could maybe have a variant that’s even more
stripped?

The downside of this is that we risk having several LLVM copies on
typical installations.

Thoughts?

Thanks,
Ludo’.

[bug#49569] [PATCH] gnu: Add make-single-arch-llvm procedure.

[Efraim Flashner]

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On Mon, Jul 26, 2021 at 06:47:14PM +0200, Ludovic Courtès wrote:
> Hi,
> 
> Efraim Flashner <efraim@flashner.co.il> skribis:
> 
> > * gnu/packages/llvm.scm (make-single-arch-llvm): New procedure.
> > (llvm-native-12, llvm-native): New variables.
> > ---
> >
> > Using this copy of llvm for packages like mesa will reduce the closure
> > of those packages. I don't suppose it would work as well for compilers
> > like rust which use LLVM for compiling and targeting different
> > architectures.
> >
> > This drops the size of llvm-12 from 167M to 111M.
> 
> That’s less impressive than I would have thought.
> 
> For Mesa perhaps we could maybe have a variant that’s even more
> stripped?
> 
> The downside of this is that we risk having several LLVM copies on
> typical installations.
> 
> Thoughts?
> 
> Thanks,
> Ludo’.

I think you're mostly shocked by the large numbers, it is a drop of 33%.

It turns out that llvm-julia uses something similar to only target one
arch, so the idea's there somewhere. We could probably add it in there
too for dlang. Icecat/icedove/mozjs-78 should be OK to switch. And
xf86-video-vmware already has mesa as an input and could likely use a
special llvm-for-mesa version.

I can look at mesa and see which libraries from llvm it links to and see
about just building those. A first look shows 50 llvm libraries from
mesa and about 150 from llvm@11, with the 4 libraries being
libOSMesa  libvulkan_radeon  libxatracker  libXvMCnouveau


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[bug#49569] [PATCH] gnu: Add make-single-arch-llvm procedure.

[Ludovic Courtès]

Efraim Flashner <efraim@flashner.co.il> skribis:

> On Mon, Jul 26, 2021 at 06:47:14PM +0200, Ludovic Courtès wrote:
>> Hi,
>> 
>> Efraim Flashner <efraim@flashner.co.il> skribis:
>> 
>> > * gnu/packages/llvm.scm (make-single-arch-llvm): New procedure.
>> > (llvm-native-12, llvm-native): New variables.
>> > ---
>> >
>> > Using this copy of llvm for packages like mesa will reduce the closure
>> > of those packages. I don't suppose it would work as well for compilers
>> > like rust which use LLVM for compiling and targeting different
>> > architectures.
>> >
>> > This drops the size of llvm-12 from 167M to 111M.
>> 
>> That’s less impressive than I would have thought.

[...]

> I think you're mostly shocked by the large numbers, it is a drop of 33%.
>
> It turns out that llvm-julia uses something similar to only target one
> arch, so the idea's there somewhere. We could probably add it in there
> too for dlang. Icecat/icedove/mozjs-78 should be OK to switch. And
> xf86-video-vmware already has mesa as an input and could likely use a
> special llvm-for-mesa version.

OK, maybe that’d be an improvement, and indeed, 33% is not negligible.

> I can look at mesa and see which libraries from llvm it links to and see
> about just building those. A first look shows 50 llvm libraries from
> mesa and about 150 from llvm@11, with the 4 libraries being
> libOSMesa  libvulkan_radeon  libxatracker  libXvMCnouveau

Makes sense.

Does Mesa require some special GPU compiler backend in addition to the
native backend?

Thanks,
Ludo’.

bug#49569: [PATCH] gnu: Add make-single-arch-llvm procedure.

[Efraim Flashner]

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I think we can drop this with llvm-for-mesa in core-updates.

-- 
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[bug#49569] [PATCH] gnu: Add make-single-arch-llvm procedure.

[Thiago Jung Bauermann via Guix-patches via]

Hello,

Em quinta-feira, 15 de julho de 2021, às 07:04:52 -03, Efraim Flashner
escreveu:
> * gnu/packages/llvm.scm (make-single-arch-llvm): New procedure.
> (llvm-native-12, llvm-native): New variables.
> ---
> 
> Using this copy of llvm for packages like mesa will reduce the closure
> of those packages. I don't suppose it would work as well for compilers
> like rust which use LLVM for compiling and targeting different
> architectures.
> 
> This drops the size of llvm-12 from 167M to 111M.

I don’t have an opinion on the issue that Ludo’ raised, just one comment
about the code below.

>  gnu/packages/llvm.scm | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/gnu/packages/llvm.scm b/gnu/packages/llvm.scm
> index 575c63c713..35cecdfd84 100644
> --- a/gnu/packages/llvm.scm
> +++ b/gnu/packages/llvm.scm
> @@ -1347,3 +1347,27 @@ LLVM."))))
>  (define-public ocaml-llvm-9 (make-ocaml-llvm llvm-9))
>  (define-public ocaml-llvm-10 (make-ocaml-llvm llvm-10))
>  (define-public ocaml-llvm-11 (make-ocaml-llvm llvm-11))
> +
> +(define* (make-single-arch-llvm llvm #:optional (system (or (%current-target-system)
> +                                                            (%current-system))))
> +  (package
> +    (inherit llvm)
> +    (name (string-append "llvm-for-" (string-downcase
> +                                       (system->llvm-target system))))

‘system->llvm-target’ needs a Nix system identifier but
‘%current-target-system’ contains a GNU triplet, so the above won’t work
when cross-compiling for armhf-linux – whose GNU triplet is
“arm-unknown-linux-gnueabihf”.

I suggest changing the default value of ‘system’ to

    (or (and=> (%current-target-system) gnu-triplet->nix-system)
        (%current-system))

which is the default argument for ‘system->llvm-target’.

If I can add a shameless plug, patch 2 of my “Target check fixes and
cleanups” series¹ adds a helper procedure with the code above. :-)

> +    (arguments
> +     (substitute-keyword-arguments (package-arguments llvm)
> +       ((#:configure-flags cf)
> +        `(cons* ,(string-append "-DLLVM_TARGETS_TO_BUILD="
> +                                (system->llvm-target system))

Same problem here.

-- 
Thanks,
Thiago

¹ https://issues.guix.gnu.org/49672