Skip to content
develop

tigris compile

Compile an ONNX or TFLite model into a binary .tgrs execution plan for deployment on embedded devices. compile prints the same summary as tigris analyze, then writes the plan only if the model fits every budget given.

Terminal window
tigris compile MODEL [OPTIONS]
Flag Type Required Description
MODEL path yes ONNX (.onnx) or TFLite (.tflite) model file
-m, --mem size (multiple) yes Memory pools, fast to slow (e.g. -m 256K or -m 256K -m 8M)
-o, --output path no Output .tgrs path (default: MODEL.tgrs)
-f, --flash size no Flash budget. No plan is written if the plan exceeds it.
-c, --compress none / lz4 no Weight compression (default: none)
--xip flag no Execute-in-place: weights read directly from flash at runtime
--input-shape NAME:1x3x224x224 (multiple) no Shape to compile an input for. Overrides what the model declares; a dimension the model leaves free is otherwise bound to 1

The compiler runs a 7-stage pipeline:

  1. Load. Import the ONNX model, fold constants, canonicalize the graph.
  2. Normalize. Fold QDQ patterns, extract quantization parameters, lower ops to TiGrIS op types.
  3. Lifetimes. Compute tensor lifetimes from the execution order.
  4. Memory Timeline. Build the activation memory timeline, compute peak memory.
  5. Temporal Partition. Split the graph into stages that each fit within the SRAM budget, inserting spill/reload ops at stage boundaries.
  6. Spatial Partition. For stages that still exceed the budget, compute spatial tiling plans (tile height, halo, receptive field) and detect chain-tileable stage sequences.
  7. Binary Emit. Serialize to the .tgrs binary format.

The output is a single .tgrs file designed for zero-copy, zero-alloc loading on the target device.

When --xip is enabled on an uncompressed plan, the runtime reads weights directly from flash via memory-mapped I/O instead of copying the full weight blob to RAM. The plan binary format is designed for memory-mapped access, so the C loader returns pointers directly into the mapped buffer. If weight compression is also enabled, weights are still stored compactly in flash but each stage’s compressed block is decompressed into the fast arena before execution.

LZ4 compression reduces plan size on flash at the cost of a small SRAM overhead for decompression at runtime.

Terminal window
tigris compile model.onnx -m 256K -c lz4 -o model.tgrs

When compression is enabled:

  • Weights are compressed per stage into individual blocks
  • At runtime, the executor decompresses one stage’s weights at a time into a reserved prefix of the SRAM arena
  • Size the complete core fast arena with tigris_fast_arena_required(&plan); it includes the simultaneous decompression reservation without duplicating the runtime’s arithmetic
  • The plan reports both compressed and uncompressed sizes

Compile with a 256K SRAM budget:

Terminal window
tigris compile ds_cnn.onnx -m 256K -o ds_cnn.tgrs
ds_cnn.onnx float32, 12 operators
input input 1x1x49x10 float32
output output 1x12 float32
fits 256.00 KiB fast memory, 1 stage
memory
unscheduled 62.50 KiB
largest tensor 31.25 KiB 1x64x25x5
this plan 62.50 KiB 193.50 KiB headroom
slow memory 2.00 KiB
flash
plan 89.94 KiB weights 88.30 KiB, overhead 1.64 KiB
as int8 23.71 KiB estimate
wrote ds_cnn.tgrs 89.94 KiB

Compile with LZ4 compression and a flash budget check. The last line says how much of the fast memory the decompressed weights take:

Terminal window
tigris compile ds_cnn.onnx -m 128K -c lz4 -f 4M -o ds_cnn.tgrs
wrote ds_cnn.tgrs 88.73 KiB, LZ4, 66.50 KiB of the 128.00 KiB fast memory holds decompressed weights

When the decompressed weights do not fit the budget, no plan is written:

Error: no plan written: decompressed weights need 88.31 KiB of fast memory, the budget is 64.00 KiB

Two-pool memory (SRAM + PSRAM):

Terminal window
tigris compile yolov5n.onnx -m 232K -m 6M -o yolov5n.tgrs