Use EXLA for Nx backend

Author: kipcole9

config/test.exs

@@ -3,4 +3,8 @@ import Config
 config :logger,
   level: :warning
 
+# Route all Nx.Defn computations (including Bumblebee featurizer
+# preprocessing) through EXLA. This includes Apple Silicon — EXLA's
+# XLA CPU path uses NEON/AMX and is significantly faster than the
+# pure-Elixir Nx.Defn.Evaluator for both preprocessing and inference.
 config :nx, :default_defn_options, [compiler: EXLA]

lib/classification.ex

@@ -271,9 +271,8 @@ if ImageVision.bumblebee_configured?() do
     end
 
     # Use EXLA as the Nx compiler when it is properly loaded and implements
-    # the current Nx.Defn.Compiler protocol. Falls back to the default
-    # evaluator when EXLA is absent or version-mismatched (e.g. EXLA 0.10
-    # paired with Nx 0.11 does not export __compile__/4).
+    # the current Nx.Defn.Compiler protocol. Falls back to the configured
+    # default (or Nx.Defn.Evaluator) when EXLA is absent or mismatched.
     defp defn_options do
       if Code.ensure_loaded?(EXLA) and function_exported?(EXLA, :__compile__, 4) do
         [compiler: EXLA]

mix.exs

@@ -61,20 +61,20 @@ defmodule ImageVision.MixProject do
       # These are declared `optional: true` so downstream consumers
       # must opt in explicitly. `image_vision` itself does not pull
       # them into the dependency graph, letting applications choose
-      # their preferred backend (EXLA for CPU/GPU, etc.) and their
-      # own Bumblebee version.
+      # their preferred backend and Bumblebee version.
       #
       # * Segmentation (`Image.Segmentation`) and object detection
       #   (`Image.Detection`) run ONNX models via Ortex.
       {:ortex, "~> 0.1", optional: true},
       #
       # * Classification (`Image.Classification`) and embedding
       #   (`Image.Classification.embed/2`) use Bumblebee servings.
-      #   Users must separately add `:exla` (or another Nx compiler)
-      #   to their own `mix.exs` for the actual Nx backend at runtime.
+      #   Users must separately add an Nx compiler to their own `mix.exs`.
       {:nx, "~> 0.11", optional: true, override: true},
       {:nx_image, "~> 0.1", optional: true},
       {:bumblebee, "~> 0.6", optional: true},
+      # EXLA provides XLA-backed Nx.Defn compilation. Works on all
+      # platforms including Apple Silicon (via XLA's CPU/NEON/AMX path).
       {:exla, "~> 0.11", optional: true},
 
       # --- Tooling ---

mix.lock

@@ -10,6 +10,7 @@
   "dialyxir": {:hex, :dialyxir, "1.4.7", "dda948fcee52962e4b6c5b4b16b2d8fa7d50d8645bbae8b8685c3f9ecb7f5f4d", [:mix], [{:erlex, ">= 0.2.8", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "b34527202e6eb8cee198efec110996c25c5898f43a4094df157f8d28f27d9efe"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.44", "f20830dd6b5c77afe2b063777ddbbff09f9759396500cdbe7523efd58d7a339c", [:mix], [], "hexpm", "4778ac752b4701a5599215f7030989c989ffdc4f6df457c5f36938cc2d2a2750"},
   "elixir_make": {:hex, :elixir_make, "0.9.0", "6484b3cd8c0cee58f09f05ecaf1a140a8c97670671a6a0e7ab4dc326c3109726", [:mix], [], "hexpm", "db23d4fd8b757462ad02f8aa73431a426fe6671c80b200d9710caf3d1dd0ffdb"},
+  "emily": {:hex, :emily, "0.3.2", "6eccc28a62b0a08628e50ce79034d36da71e78c3c24dafbd5cf20ae880899a08", [:mix], [{:axon, "~> 0.7", [hex: :axon, repo: "hexpm", optional: true]}, {:bumblebee, "~> 0.6", [hex: :bumblebee, repo: "hexpm", optional: true]}, {:elixir_make, "~> 0.9", [hex: :elixir_make, repo: "hexpm", optional: false]}, {:fine, "~> 0.1", [hex: :fine, repo: "hexpm", optional: false]}, {:nx, "~> 0.10", [hex: :nx, repo: "hexpm", optional: false]}, {:tokenizers, "~> 0.5", [hex: :tokenizers, repo: "hexpm", optional: true]}], "hexpm", "74e876a0dde427d021f7685f5b7d0679eb41861d48993c2bf9fdc7adc1104b2a"},
   "erlex": {:hex, :erlex, "0.2.8", "cd8116f20f3c0afe376d1e8d1f0ae2452337729f68be016ea544a72f767d9c12", [:mix], [], "hexpm", "9d66ff9fedf69e49dc3fd12831e12a8a37b76f8651dd21cd45fcf5561a8a7590"},
   "ex_doc": {:hex, :ex_doc, "0.40.1", "67542e4b6dde74811cfd580e2c0149b78010fd13001fda7cfeb2b2c2ffb1344d", [:mix], [{:earmark_parser, "~> 1.4.44", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "bcef0e2d360d93ac19f01a85d58f91752d930c0a30e2681145feea6bd3516e00"},
   "exla": {:hex, :exla, "0.11.0", "1428de9edcb297480a64611d3a72fcefe13c93c115bba6d38e910583c37e38c8", [:make, :mix], [{:elixir_make, "~> 0.6", [hex: :elixir_make, repo: "hexpm", optional: false]}, {:fine, "~> 0.1", [hex: :fine, repo: "hexpm", optional: false]}, {:nimble_pool, "~> 1.0", [hex: :nimble_pool, repo: "hexpm", optional: false]}, {:nx, "~> 0.11.0", [hex: :nx, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4.0 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}, {:xla, "~> 0.10.0", [hex: :xla, repo: "hexpm", optional: false]}], "hexpm", "1067207c802bd6f28cded6a2664979ee2e25dddce95cb84be3f0a3ebfbab2c74"},