bug#63986: Julia is very slow

[Simon Tournier]

Hi,

On Thu, 22 Jun 2023 at 19:25, Efraim Flashner <efraim@flashner.co.il> wrote:

> It might need some tuning anyway, currently we have julia for i686 and
> switching to solely openblas-ilp64 we'd lose 32-bit support.

Yes, indeed.  This attached patch conditionally switches.

>From 9e1912148d4a691a5484fc7f87597b579ba61785 Mon Sep 17 00:00:00 2001
Message-Id: 
<9e1912148d4a691a5484fc7f87597b579ba61785.1687453627.git.zimon.toutoune@gmail.com>
From: Simon Tournier <zimon.toutoune@gmail.com>
Date: Thu, 22 Jun 2023 17:45:50 +0200
Subject: [PATCH v2] gnu: julia: Conditionally use openblas with ILP64 support.

Fixes <https://bugs.gnu.org/63986>.
Reported by Cayetano Santos <csantosb@inventati.org>.

* gnu/packages/julia.scm (julia)[arguments]<#:make-flags>: Conditionally use
OpenBLAS with ILP64 support for x86-64 target.
[inputs]: Conditionally replace openblas by openblas-ilp64 for x86-64 target.
---
 gnu/packages/julia.scm | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/gnu/packages/julia.scm b/gnu/packages/julia.scm
index ba54175822..3ffd1fa4cb 100644
--- a/gnu/packages/julia.scm
+++ b/gnu/packages/julia.scm
@@ -483,8 +483,12 @@ (define-public julia
              `("USE_BLAS64=0")
              '())
 
-         "LIBBLAS=-lopenblas"
-         "LIBBLASNAME=libopenblas"
+         ,@(if (target-x86-64?)
+             `("USE_BLAS64=1"
+               "LIBBLAS=-lopenblas_ilp64"
+               "LIBBLASNAME=libopenblas_ilp64")
+             `("LIBBLAS=-lopenblas"
+               "LIBBLASNAME=libopenblas"))
 
          (string-append "UTF8PROC_INC="
                         (assoc-ref %build-inputs "utf8proc")
@@ -513,7 +517,9 @@ (define-public julia
        ("llvm" ,llvm-julia)
        ("mbedtls-apache" ,mbedtls-apache)
        ("mpfr" ,mpfr)
-       ("openblas" ,openblas)
+       ,@(if (target-x86-64?)
+             `(("openblas" ,openblas-ilp64))
+             `(("openblas" ,openblas)))
        ("openlibm" ,openlibm)
        ("p7zip" ,p7zip)
        ("pcre2" ,pcre2)

base-commit: 37c2e94cec6cb8b5e0e93e7b6c712c3b187ca5db
-- 
2.38.1


Well, the current recipe could be improved but let focus on the current
bug report.  And I guess the slowness come from an incorrect use of BLAS
for x86-64.  That seems fixed by the patch, no?

Cheers,
simon