Files
Jesse Gross 2e036e7cdf mlx, mlxrunner: move the MLX engine out of x/
The MLX runner is the only Go inference runner left and is no longer
experimental, so its packages leave x/. The bindings become a top-level
mlx package beside the carried patches in mlx/compat, mirroring how
llama/ holds the llama.cpp integration, and the runner becomes mlxrunner
with the architectures nested under the package they implement.
Subpackages move with their parent unless listed.

  x/mlxrunner/mlx            mlx
  x/internal/mlxthread       mlx/mlxthread
  x/internal/mlxthreadtest   mlx/mlxthread/mlxthreadtest
  x/internal/mlxtest         mlx/mlxtest
  x/quant                    mlx/quant
  mlx/compat/*.patch         mlx/compat/mlx-c   (MLX patches go in mlx/compat/mlx)
  x/mlxrunner                mlxrunner
  x/models/nn                mlxrunner/nn
  x/models/<arch>            mlxrunner/model/<arch>
  x/mlxrunner/imports.go     mlxrunner/model/architectures   (new package)
  x/create                   create
  x/safetensors              fs/safetensors
  x/tokenizer                mlxrunner/tokenizer

Every package keeps its name, so the Go changes are the import path
rewrites the moves force, and the CMake, Dockerfile, CI cache keys, drift
check and Darwin payload script follow the new paths. Four edits are not
paths: the runner's blank architecture imports become the package
mlxrunner/model/architectures, so the list to extend for a new model sits
beside the architecture directories; a depguard rule keeps the two test
harnesses out of non-test code, as the x/internal placement used to; the
CI change filter's two entries for the long-deleted x/imagegen/mlx now
name the bindings' CMake project and the carried patches, so a change to
either builds the payload; and the tokenizer parity test reads its
fixtures from its own testdata instead of walking out of x/.

x/server and x/imagegen/manifest stay for the next two commits.
2026-09-16 14:06:08 -07:00

62 lines
2.4 KiB
Go

package create
import (
"encoding/json"
"fmt"
"strings"
)
// cohere2MoeImportTransform adjusts quantization for Cohere2 MoE imports
// (Command A family / North models).
type cohere2MoeImportTransform struct {
numLayers int
}
func newCohere2MoeImportTransform(rawConfig json.RawMessage) (quantizePolicy, error) {
var cfg struct {
NumHiddenLayers int `json:"num_hidden_layers"`
}
if err := json.Unmarshal(rawConfig, &cfg); err != nil {
return nil, fmt.Errorf("cohere2moe: parse config.json: %w", err)
}
return cohere2MoeImportTransform{numLayers: cfg.NumHiddenLayers}, nil
}
func (t cohere2MoeImportTransform) quantizationType(name string, shape []int32, quantize string) string {
base := normalizeQuantType(quantize)
// The embedding serves double duty: lookup (via QuantizedEmbedding) and the
// tied lm_head projection (via AsLinear). With a 262k vocab the bf16
// embedding dominates decode bandwidth through the lm_head matmul, so
// quantize it to the 8-bit variant of the requested mode, or keep source
// precision when that does not fit.
if isEmbedTokensWeight(name) && len(shape) == 2 {
return promoteEmbedding(shape, base)
}
// The MoE router picks the top-k expert set; quantization noise there can
// flip expert selection and compound downstream. It is tiny, so keep it in
// source precision. (GetTensorQuantization already skips "mlp.gate.weight";
// kept explicit here so renames in the default policy cannot regress this.)
if strings.HasSuffix(name, ".mlp.gate.weight") {
return ""
}
// Sensitive tensors (v_proj, k_proj, down_proj) get higher precision only
// at quantization-sensitive layer positions (useMoreBits) instead of the
// default policy's blanket promotion. The blanket int8 down_proj costs
// ~25% of decode bandwidth on a top-8 MoE; the layer-position heuristic
// keeps the early/late layers (and every third in between) at 8 bits where
// residual-stream error matters most.
isSensitive := strings.Contains(name, ".v_proj") || strings.Contains(name, ".k_proj") || strings.Contains(name, "down_proj")
if isSensitive && eightBit(base) != base && t.numLayers > 0 {
if idx := layerIndex(name); idx >= 0 {
// Bypass GetTensorQuantization's blanket promotion — the
// layer-position heuristic is authoritative here.
return sensitiveType(useMoreBits(idx, t.numLayers), shape, base)
}
}
return GetTensorQuantization(name, shape, quantize)
}