[BUG] unrolled loops in stdlib killing compilation (LayoutTensor copy_from())

Bug description

Actual behavior

(mojollm) (base) me@mypc:~/Desktop/GitHub/mojollm/src$ mojo bugreport.mojo max/kernels/src/layout/layout_tensor.mojo:5472:9: warning: parameter for unrolling loop more than 65536 times may cause long compilation time and large code size. (use '--loop-unrolling-warn-threshold' to increase the threshold or set to 0 to disable this warning)Killed

Expected behavior

build / run without crashing

Steps to reproduce

Use copy_from() on a LayoutTensor of size 1024 x 1024 or greater. 1024 x 512 has been trying to compile for 10+minutes now, hasn't been killed yet.

https://godbolt.org/z/odcKa57GK

bugreportcopyfrom.txt

System information

(mojollm) (base) me@me-B650I-AORUS-ULTRA:~/Desktop/GitHub/mojollm/src$ pixi infoSystem

   Pixi version: 0.48.2
       Platform: linux-64

Virtual packages: __unix=0=0 : __linux=6.14.0=0 : __glibc=2.39=0 : __cuda=13.0=0 : __archspec=1=zen4 Cache dir: /home/me/.cache/rattler/cache Auth storage: /home/me/.rattler/credentials.json Config locations: /home/me/.pixi/config.toml

Global

        Bin dir: /home/me/.pixi/bin
Environment dir: /home/me/.pixi/envs
   Manifest dir: /home/me/.pixi/manifests/pixi-global.toml

Workspace

           Name: mojollm
        Version: 0.1.0
  Manifest file: /home/me/Documents/GitHub/mojollm/pixi.toml
   Last updated: 16-01-2026 09:43:37

Environments

    Environment: default
       Features: default
       Channels: https://conda.modular.com/max-nightly, conda-forge

Dependency count: 2 Dependencies: mojo, max Target platforms: linux-64 Prefix location: /home/me/Documents/GitHub/mojollm/.pixi/envs/default

• Provide version information for MAX (includes Mojo) by pasting the output of pixi list max.

(mojollm) (base) me@me-B650I-AORUS-ULTRA:/Desktop/GitHub/mojollm/src$ pixi list max~~~~~~~~Package Version Build Size Kind Source~~~~~~~~max 26.1.0.dev2026011405 3.14release 5.8 MiB conda https://conda.modular.com/max-nightly/~~~~max-core 26.1.0.dev2026011405 release 120.6 MiB conda https://conda.modular.com/max-nightly/~~~~(mojollm) (base) me@me-B650I-AORUS-ULTRA:/Desktop/GitHub/mojollm/src$ pixi list mojoPackage Version Build Size Kind Sourcemojo 0.26.1.0.dev2026011405 release 84.8 MiB conda https://conda.modular.com/max-nightly/mojo-compiler 0.26.1.0.dev2026011405 release 82.4 MiB conda https://conda.modular.com/max-nightly/mojo-python 0.26.1.0.dev2026011405 release 23.7 KiB conda https://conda.modular.com/max-nightly/