Add a toy llama test for numerics

sharktank/sharktank/models/llama/toy_llama.py

@@ -18,10 +18,8 @@
 parser.add_argument("-o", "--output", default="/tmp/toy_llama.irpa")
 
 
-def main():
-    args = parser.parse_args()
-    torch.manual_seed(args.seed)
-
+def generate(seed):
+    torch.manual_seed(seed)
     dtype = torch.float16
     block_seq_stride = 16
     max_blocks = 8
@@ -56,6 +54,12 @@ def main():
         config=config,
         vocab_size=vocabulary_size,
     )
+    return theta, config
+
+
+def main():
+    args = parser.parse_args()
+    theta, config = generate(args.seed)
 
     config_dict = config.hp.to_gguf_props()
 

sharktank/tests/models/llama/test_llama.py

@@ -0,0 +1,50 @@
+# Copyright 2025 Advanced Micro Devices, Inc
+#
+# Licensed under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+
+from sharktank.models.llama.llama import PagedLlamaModelV1
+from sharktank.models.llama.toy_llama import generate
+from sharktank.utils.create_cache import create_paged_kv_cache
+
+import pytest
+import torch
+
+def test_llama():
+    theta, config = generate(12345)
+    model = PagedLlamaModelV1(theta=theta, config=config)
+
+    ids = [0, 208, 214, 29, 19, 86, 176, 120, 120, 80, 120, 208, 37, 157, 191, 137]
+    seq_len = len(ids)
+
+    blocks = (seq_len - 1) // config.block_seq_stride
+    blocks = blocks + 1
+    padded_length = blocks * config.block_seq_stride
+    padding = padded_length - seq_len
+    ids = ids + [0] * padding
+
+    ids = torch.asarray([ids], dtype=torch.int64)
+    block_ids = torch.asarray([[i for i in range(blocks)]]).to(torch.int64)
+
+    cache=create_paged_kv_cache(config)
+    cache_state = model.cache.allocate(
+        page_count=config.hp.context_length // config.block_seq_stride
+    )
+
+    logits = model.prefill(
+        tokens=ids,
+        attention_mask=None,
+        cache_state=cache_state,
+        seq_block_ids=block_ids
+        )
+
+    # Remove padding
+    ids = ids[:, :seq_len]
+    logits = logits[:, :seq_len, :]
+
+    ids = ids[0, 1:]
+    logits = logits[0, :-1]
+    cross_entropy = torch.nn.functional.cross_entropy(logits, ids)
+    assert pytest.approx(0.577, 1e-2) == cross_entropy