CUDA: Fuse MMVQ post-scale for NVFP4 (#24481)
* CUDA: Fuse MMVQ for NVFP4 and BS 1
TODO:
1. Add tests to test-backend-ops (did verify correctness manually for
one model)
2. Reorder bias/scale once PRs for NVFP4 are merged/landed
* Add dense MMVQ fusion as well
Perf numbers on B4500. Note qwen35 is FP8->Q8
+ ./scripts/compare-llama-bench.py -b master -c osimons/nvfp4_fuse_mmvq --tool llama-bench -i llama-bench.sqlite
| Model | Test | t/s master | t/s osimons/nvfp4_fuse_mmvq | Speedup |
|:-------------------------|:-------------|-------------:|------------------------------:|----------:|
| qwen35moe 35B.A3B NVFP4 | tg128@d32768 | 150.15 | 156.29 | 1.04 |
| qwen35moe 35B.A3B Q4_K_M | tg128@d32768 | 157.91 | 157.64 | 1.00 |
Perf numbers on DGX Spark
+ ./scripts/compare-llama-bench.py -b master -c osimons/nvfp4_fuse_mmvq --tool llama-bench -i llama-bench.sqlite
| Model | Test | t/s master | t/s osimons/nvfp4_fuse_mmvq | Speedup |
|:-------------------------|:-------------|-------------:|------------------------------:|----------:|
| qwen35moe 35B.A3B NVFP4 | tg128@d32768 | 58.31 | 59.69 | 1.02 |
| qwen35moe 35B.A3B Q4_K_M | tg128@d32768 | 54.94 | 54.79 | 1.00 |
* Add tests for the added fusion ops
* Cleanup test-backend-ops
* Cleanup ggml-cuda/mmvq
1. Unrestrict post-scale fusion
2. Rename names accordingly
3. Remove env variable to disable fusion
* Merge old mul_mat patterns into the lane-based approach
* Enable fusion for MoE in shared MMVQ
* Restrict scale_view_nodes, enroll MM + ADD into lane-matcher
* Refactor mmvq loads, still does not help non-nvfp4 kernels
* Restrict scale-fusion to NVFP4
This is necessary, as the prolog is quite heavy in GEMV for some
quants/model configs, leading to net perf regression.
We should really be looking to refactor this such that ratio of
prologue/hot-loop/epilogue is better on the hot-loop
front:
+ ./scripts/compare-llama-bench.py -b master -c c1b9381d327e063cc846b46b59708444b66dc4d8 --tool llama-bench -i llama-bench.sqlite
| CPU | Model | Test | t/s master | t/s c1b9381d3 | Speedup |
|:----------------------------|:-------------------------|:-------------|-------------:|----------------:|----------:|
| INTEL(R) XEON(R) GOLD 6542Y | gemma4 26B.A4B NVFP4 | tg128@d32768 | 151.70 | 154.32 | 1.02 |
| INTEL(R) XEON(R) GOLD 6542Y | gemma4 26B.A4B Q4_K_M | tg128@d32768 | 187.95 | 185.73 | 0.99 |
| INTEL(R) XEON(R) GOLD 6542Y | gpt-oss 20B MXFP4 MoE | tg128@d32768 | 304.62 | 300.69 | 0.99 |
| INTEL(R) XEON(R) GOLD 6542Y | qwen35moe 35B.A3B NVFP4 | tg128@d32768 | 193.72 | 211.99 | 1.09 |
| INTEL(R) XEON(R) GOLD 6542Y | qwen35moe 35B.A3B Q4_K_M | tg128@d32768 | 217.76 | 218.15 | 1.00
* Reorder scale & bias-add to adhere to #24331
* Restrict lane scale to NVFP4
Don't need to test unfused combinations
* Cleanup
* Merge single-lane mm-fusion helpers
* Refactor and clean-up host-side fusion logic
* Move gate_bias and scale into the same active-thread guard
Latest perf numbers:
B6000
build: 5b7d9f272 (9578)
+ ./scripts/compare-llama-bench.py -b master -c osimons/nvfp4_fuse_mmvq --tool llama-bench -i llama-bench.sqlite
| CPU | Model | Test | t/s master | t/s osimons/nvfp4_fuse_mmvq | Speedup |
|:----------------------------|:-------------------------|:-------------|-------------:|------------------------------:|----------:|
| INTEL(R) XEON(R) GOLD 6542Y | gemma4 26B.A4B NVFP4 | tg128@d32768 | 151.79 | 154.10 | 1.02 |
| INTEL(R) XEON(R) GOLD 6542Y | gemma4 26B.A4B Q4_K_M | tg128@d32768 | 187.90 | 187.27 | 1.00 |
| INTEL(R) XEON(R) GOLD 6542Y | gpt-oss 20B MXFP4 MoE | tg128@d32768 | 303.77 | 306.56 | 1.01 |
| INTEL(R) XEON(R) GOLD 6542Y | qwen35moe 35B.A3B NVFP4 | tg128@d32768 | 193.41 | 207.99 | 1.08 |
| INTEL(R) XEON(R) GOLD 6542Y | qwen35moe 35B.A3B Q4_K_M | tg128@d32768 | 217.60 | 218.58 | 1.00 |
DGX Spark
build: 5b7d9f272 (9578)
+ ./scripts/compare-llama-bench.py -b master -c osimons/nvfp4_fuse_mmvq --tool llama-bench -i llama-bench.sqlite
| CPU | Model | Test | t/s master | t/s osimons/nvfp4_fuse_mmvq | Speedup |
|:------|:-------------------------|:-------------|-------------:|------------------------------:|----------:|
| CPU | gemma4 26B.A4B NVFP4 | tg128@d32768 | 34.61 | 34.84 | 1.01 |
| CPU | gemma4 26B.A4B Q4_K_M | tg128@d32768 | 46.95 | 46.90 | 1.00 |
| CPU | gpt-oss 20B MXFP4 MoE | tg128@d32768 | 64.84 | 64.62 | 1.00 |
| CPU | qwen35moe 35B.A3B NVFP4 | tg128@d32768 | 59.63 | 60.72 | 1.02 |
| CPU | qwen35moe 35B.A3B Q4_K_M | tg128@d32768 | 56.53 | 56.55 | 1.00 |
PPL values for 5 chunks:
this PR
model mode ppl uncertainty log
/mnt/share/gguf/unsloth/Qwen3.6-35B-A3B-GGUF/Qwen3.6-35B-A3B-UD-Q4_K_M.gguf fusion_enabled 5.2892 0.35389 ppl-value-checks/Qwen3.6-35B-A3B-UD-Q4_K_M.fusion_enabled.log
/mnt/share/gguf/unsloth/Qwen3.6-35B-A3B-GGUF/Qwen3.6-35B-A3B-UD-Q4_K_M.gguf fusion_disabled 5.2742 0.35215 ppl-value-checks/Qwen3.6-35B-A3B-UD-Q4_K_M.fusion_disabled.log
/mnt/share/gguf/nvidia/Qwen3.6-35B-A3B-2.06GB-per-token-CT/Qwen3.6-35B-A3B-2.06GB-per-token-CT_fp8_q8.gguf fusion_enabled 5.4487 0.36866 ppl-value-checks/Qwen3.6-35B-A3B-2.06GB-per-token-CT_fp8_q8.fusion_enabled.log
/mnt/share/gguf/nvidia/Qwen3.6-35B-A3B-2.06GB-per-token-CT/Qwen3.6-35B-A3B-2.06GB-per-token-CT_fp8_q8.gguf fusion_disabled 5.4403 0.36782 ppl-value-checks/Qwen3.6-35B-A3B-2.06GB-per-token-CT_fp8_q8.fusion_disabled.log
/mnt/share/gguf/nvidia/Gemma-4-26B-A4B-NVFP4/Gemma-4-26B-A4B-NVFP4_fp8_q8.gguf fusion_enabled 17342.4348 3703.13932 ppl-value-checks/Gemma-4-26B-A4B-NVFP4_fp8_q8.fusion_enabled.log
/mnt/share/gguf/nvidia/Gemma-4-26B-A4B-NVFP4/Gemma-4-26B-A4B-NVFP4_fp8_q8.gguf fusion_disabled 18627.0624 3998.42475 ppl-value-checks/Gemma-4-26B-A4B-NVFP4_fp8_q8.fusion_disabled.log
/mnt/share/gguf/ggml-org/gpt-oss-20b-GGUF/gpt-oss-20b-mxfp4.gguf fusion_enabled 363.8913 33.14007 ppl-value-checks/gpt-oss-20b-mxfp4.fusion_enabled.log
/mnt/share/gguf/ggml-org/gpt-oss-20b-GGUF/gpt-oss-20b-mxfp4.gguf fusion_disabled 363.8913 33.14007 ppl-value-checks/gpt-oss-20b-mxfp4.fusion_disabled.log
/mnt/share/gguf/unsloth/gemma-4-26B-A4B-it-GGUF/gemma-4-26B-A4B-it-UD-Q4_K_XL.gguf fusion_enabled 17330.3926 3716.70472 ppl-value-checks/gemma-4-26B-A4B-it-UD-Q4_K_XL.fusion_enabled.log
/mnt/share/gguf/unsloth/gemma-4-26B-A4B-it-GGUF/gemma-4-26B-A4B-it-UD-Q4_K_XL.gguf fusion_disabled 17933.9524 3883.17066 ppl-value-checks/gemma-4-26B-A4B-it-UD-Q4_K_XL.fusion_disabled.log
master:
summary: ppl-value-checks/summary.tsv
model mode ppl uncertainty log
/mnt/share/gguf/unsloth/Qwen3.6-35B-A3B-GGUF/Qwen3.6-35B-A3B-UD-Q4_K_M.gguf fusion_enabled 5.2892 0.35389 ppl-value-checks/Qwen3.6-35B-A3B-UD-Q4_K_M.fusion_enabled.log
/mnt/share/gguf/unsloth/Qwen3.6-35B-A3B-GGUF/Qwen3.6-35B-A3B-UD-Q4_K_M.gguf fusion_disabled 5.2742 0.35215 ppl-value-checks/Qwen3.6-35B-A3B-UD-Q4_K_M.fusion_disabled.log
/mnt/share/gguf/nvidia/Qwen3.6-35B-A3B-2.06GB-per-token-CT/Qwen3.6-35B-A3B-2.06GB-per-token-CT_fp8_q8.gguf fusion_enabled 5.4487 0.36866 ppl-value-checks/Qwen3.6-35B-A3B-2.06GB-per-token-CT_fp8_q8.fusion_enabled.log
/mnt/share/gguf/nvidia/Qwen3.6-35B-A3B-2.06GB-per-token-CT/Qwen3.6-35B-A3B-2.06GB-per-token-CT_fp8_q8.gguf fusion_disabled 5.4403 0.36782 ppl-value-checks/Qwen3.6-35B-A3B-2.06GB-per-token-CT_fp8_q8.fusion_disabled.log
/mnt/share/gguf/nvidia/Gemma-4-26B-A4B-NVFP4/Gemma-4-26B-A4B-NVFP4_fp8_q8.gguf fusion_enabled 17342.4348 3703.13932 ppl-value-checks/Gemma-4-26B-A4B-NVFP4_fp8_q8.fusion_enabled.log
/mnt/share/gguf/nvidia/Gemma-4-26B-A4B-NVFP4/Gemma-4-26B-A4B-NVFP4_fp8_q8.gguf fusion_disabled 18627.0624 3998.42475 ppl-value-checks/Gemma-4-26B-A4B-NVFP4_fp8_q8.fusion_disabled.log
/mnt/share/gguf/ggml-org/gpt-oss-20b-GGUF/gpt-oss-20b-mxfp4.gguf fusion_enabled 363.8913 33.14007 ppl-value-checks/gpt-oss-20b-mxfp4.fusion_enabled.log
/mnt/share/gguf/ggml-org/gpt-oss-20b-GGUF/gpt-oss-20b-mxfp4.gguf fusion_disabled 363.8913 33.14007 ppl-value-checks/gpt-oss-20b-mxfp4.fusion_disabled.log
/mnt/share/gguf/unsloth/gemma-4-26B-A4B-it-GGUF/gemma-4-26B-A4B-it-UD-Q4_K_XL.gguf fusion_enabled 17330.3926 3716.70472 ppl-value-checks/gemma-4-26B-A4B-it-UD-Q4_K_XL.fusion_enabled.log
/mnt/share/gguf/unsloth/gemma-4-26B-A4B-it-GGUF/gemma-4-26B-A4B-it-UD-Q4_K_XL.gguf fusion_disabled 17933.9524 3883.17066 ppl-value-checks/gemma-4-26B-A4B-it-UD-Q4_K_XL.fusion_disabled.log
* Allow views to weights in ggml_can_fuse_subgraph
* Remove gate_first from test_mul_mat_vec_fusion
* Ditch lane-parsing approach in favor of hard-coded patterns
* Apply suggestions from code review
Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
* Rename ggml_is_constant_view_src to ggml_is_constant
* Finish renaming of 0905129e9d12e2bc6f16d6d3cc4e6b40606fc893
* Readd descriptive prints for fusion debugging
* Add weight-buffer pre-allocation to `test_case`
This is required so we correctly test fusion of NVFP4.
* Update ggml/src/ggml.c
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
* Add 2nd context for weights as suggested by @JohannesGaessler
This reflects more natural use of ggml compared to artifically
pre-allocating weights into the same context
* Exclude fused tests from gradient mode
I'm unsure of the current state, but naively every fusion pattern
should require its own backpropagation implementation. I don't see these
implemented for the CUDA backend, so we can disable tests to avoid
triggering GGML_ASSERT for
ggml_tensor * build_graph(ggml_context * ctx) override {
GGML_ASSERT(!use_weight_context());
return build_graph(ctx, nullptr);
}
* Apply suggestions from code review
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
---------
Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
