[sharktank] Revert "[llama] Added the fused rotary embedding kernel (#…

…719)" (#752)

This reverts commit fc9576b, which
causes segmentation fault at Llama prefill in IREE runtime.

sharktank/sharktank/examples/export_paged_llm_v1.py

@@ -79,6 +79,7 @@ def main():
         hp,
         tensor_parallelism_size=tensor_parallelism_size,
         use_hf=False,
+        static_tables=False,  # Rely on the compiler for hoisting tables.
         kv_cache_type="direct" if args.bs == [1] else "paged",
         attention_kernel=args.attention_kernel,
         block_seq_stride=args.block_seq_stride,
@@ -218,16 +219,22 @@ def _(model, tokens, seq_lens, seq_block_ids, cs):
             else:
                 cache_tensors = cs
 
+            sl = tokens.shape[1]
+            input_mask = model.input_mask(seq_lens, sl)
+            attention_mask = model.attention_mask(input_mask)
+
             if llama_config.tensor_parallelism_size != 1:
                 shard_count = llama_config.tensor_parallelism_size
 
                 tokens = ops.replicate(tokens, count=shard_count)
+                attention_mask = ops.replicate(attention_mask, count=shard_count)
                 seq_block_ids = ops.replicate(seq_block_ids, count=shard_count)
+
                 cache_tensors = repack_cache(cs, cache_shard_dim)
 
             logits = model.prefill(
                 tokens,
-                attention_mask=None,  # We rely on causal attention
+                attention_mask=attention_mask,
                 seq_block_ids=seq_block_ids,
                 cache_state=cache_tensors,
             )

sharktank/sharktank/kernels/__init__.py

@@ -10,7 +10,6 @@
 from .mmt_block_scaled_offset_q4 import *
 from .mmt_block_scaled_q8 import *
 from .mmt_super_block_scaled_offset_q4 import *
-from .rotary import *
 from .batch_matmul_transpose_b import *
 from .conv_2d_nchw_fchw import *
 from .pooling_nchw_sum import *

sharktank/sharktank/layers/paged_llama_attention_block.py

@@ -221,7 +221,7 @@ def repeat_kv(x: torch.Tensor) -> torch.Tensor:
                 k=keys,  # [bs, ..., sl, dim]
                 v=values,  # [bs, ..., sl, dim]
                 a=attention_mask,  # [bs, ..., sl, sl]
-                is_causal=attention_mask is None,  # assumes causal masking when true
+                is_causal=False,  # assumes causal masking when true
                 scale=None,  # defaults to 1/sqrt(dim)
             )
 

sharktank/sharktank/layers/rotary_embedding.py

@@ -11,7 +11,6 @@
 
 from .base import BaseLayer
 from .. import ops
-from .. import kernels
 from ..types import SplitPrimitiveTensor, ReplicatedTensor, unbox_tensor
 
 
@@ -26,6 +25,7 @@ def __init__(
         rope_freq_base: Optional[float],
         device: Optional[torch.device] = None,
         use_hf: bool = False,
+        static_tables: bool = False,
         use_table: bool = True,
         tensor_parallelism_size: int = 1,
     ):
@@ -34,44 +34,60 @@ def __init__(
         self.rope_dimension_count = rope_dimension_count
         self.max_seqlen = max_seqlen
         self.use_hf = use_hf
+        self.static_tables = static_tables
         self.use_table = use_table
 
         self.rope_freq_base = rope_freq_base if rope_freq_base is not None else 10000.0
         self.tensor_parallelism_size = tensor_parallelism_size
+        if static_tables:
+            ops.module_register_buffer(
+                self, "static_rotary_embed_table", self._create_rotary_embed_table()
+            )
+        else:
+            self.static_rotary_embed_table = None
 
     @property
     def rotary_embed_table(self):
-        return self._create_rotary_embed_table()
+        if self.use_table:
+            if self.static_tables:
+                return self.static_rotary_embed_table
+            return self._create_rotary_embed_table()
+
+        return None
 
     def forward(
         self,
         *,
         xt: Union[torch.Tensor, SplitPrimitiveTensor],
         start_index: int,
     ):
-        table = self.rotary_embed_table
-        if not isinstance(xt, SplitPrimitiveTensor):
+        if isinstance(xt, SplitPrimitiveTensor):
+            rotary_shards = [None] * xt.shard_count
+            if self.rotary_embed_table is not None:
+                assert (
+                    isinstance(self.rotary_embed_table, ReplicatedTensor)
+                    and xt.shard_count == self.rotary_embed_table.shard_count
+                )
+                rotary_shards = [
+                    unbox_tensor(shard) for shard in self.rotary_embed_table.shards
+                ]
+
+            xt_shards = [
+                self.forward_unsharded(
+                    xt=unbox_tensor(xt_shard),
+                    start_index=start_index,
+                    rotary_embed_table=rotary_shard,
+                )
+                for xt_shard, rotary_shard in zip(xt.shards, rotary_shards)
+            ]
+            xt = SplitPrimitiveTensor(ts=xt_shards, shard_dim=xt.shard_dim)
+            return xt
+        else:
             return self.forward_unsharded(
                 xt=xt,
                 start_index=start_index,
-                rotary_embed_table=table,
-            )
-
-        assert (
-            isinstance(table, ReplicatedTensor) and xt.shard_count == table.shard_count
-        )
-        rotary_shards = [unbox_tensor(shard) for shard in table.shards]
-
-        xt_shards = [
-            self.forward_unsharded(
-                xt=unbox_tensor(xt_shard),
-                start_index=start_index,
-                rotary_embed_table=rotary_shard,
+                rotary_embed_table=self.rotary_embed_table,
             )
-            for xt_shard, rotary_shard in zip(xt.shards, rotary_shards)
-        ]
-        xt = SplitPrimitiveTensor(ts=xt_shards, shard_dim=xt.shard_dim)
-        return xt
 
     def _create_interleaved_tensor(_, dim):
         """Creates a tensor which indexes an tensor such that
@@ -127,17 +143,18 @@ def forward_unsharded(
         # Offset the table based on starting position.
         if self.use_table:
             freqs_cis = rotary_embed_table[start_index : start_index + sl, :]
-            freqs_cis = freqs_cis[0:sl, :]
+            freqs_cis = freqs_cis[None, 0:sl, None, :]
         else:
             freqs_cis = torch.arange(sl, device=xt.device) + start_index
-            freqs_cis = self._compute_rotary_embed_table(freqs_cis)
+            freqs_cis = self._compute_rotary_embed_table(freqs_cis)[None, :, None, :]
 
         assert (
-            freqs_cis.shape[0] >= sl
+            freqs_cis.shape[1] >= sl
         ), f"Sequence length longer than embedding table ({sl} vs {freqs_cis.shape[0]})"
 
-        freqs_cis = ops.repeat(freqs_cis[None, :, :], (xt_.shape[0], 1, 1))
-        xt_out = kernels.apply_rotary_embedding(xt_.to(freqs_cis.dtype), freqs_cis)
+        xt_ = ops.view_as_complex(xt_)
+        xt_ = xt_ * freqs_cis
+        xt_out = ops.view_as_real(xt_)
 
         if self.use_hf:
             xt_out = xt_out[..., self._create_ordering_tensor(xt_out.shape[-1])]
@@ -164,7 +181,7 @@ def compute_batch_mask(
         self.trace_tensor("rope.positions_seq", positions_seq)
 
         if self.use_table:
-            freqs_cis = self.rotary_embed_table[positions_seq.flatten()]
+            freqs_cis = self.rotary_embed_table[positions_seq]
         else:
             shape = positions_seq.shape
             if isinstance(positions_seq, ReplicatedTensor):
@@ -175,8 +192,11 @@ def compute_batch_mask(
                 freqs_cis = ReplicatedTensor(ts=ts)
             else:
                 freqs_cis = self._compute_rotary_embed_table(positions_seq.flatten())
+                freqs_cis = freqs_cis.unflatten(0, shape)
 
-        return freqs_cis.unsqueeze(1)
+        # Unsqueeze a unit dim for attention heads.
+        broadcast_freqs_cis = freqs_cis.unsqueeze(2)
+        return broadcast_freqs_cis
 
     def apply_batched_mask(
         self,
@@ -212,7 +232,9 @@ def apply_batched_mask_unsharded(self, *, xt: torch.Tensor, mask: torch.Tensor):
         if self.use_hf:
             xt = xt[..., self._create_interleaved_tensor(xt.shape[-1])]
 
-        xt_out = kernels.apply_rotary_embedding(xt.to(mask.dtype), mask)
+        xt_ = ops.view_as_complex(xt)
+        xt_ = xt_ * mask
+        xt_out = ops.view_as_real(xt_)
 
         if self.use_hf:
             xt_out = xt_out[..., self._create_ordering_tensor(xt_out.shape[-1])]
@@ -222,10 +244,14 @@ def apply_batched_mask_unsharded(self, *, xt: torch.Tensor, mask: torch.Tensor):
     def _compute_rotary_embed_table(self, t):
         dim = self.rope_dimension_count
         freqs = 1.0 / (
-            self.rope_freq_base ** ((torch.arange(0, dim) // 2).float() / dim * 2.0)
+            self.rope_freq_base ** (torch.arange(0, dim, 2)[: (dim // 2)].float() / dim)
         )
         freqs = torch.outer(t, freqs).float()
-        return freqs
+
+        cos = torch.cos(freqs)
+        sin = torch.sin(freqs)
+        complex = torch.complex(cos, sin)
+        return complex
 
     def _create_rotary_embed_table(self):
         t = torch.arange(self.max_seqlen, device=self.device)

sharktank/sharktank/models/llama/llama.py

@@ -67,6 +67,7 @@ def __init__(self, theta: Theta, config: LlamaModelConfig):
         super().__init__(
             theta,
             context_length=config.hp.context_length,
+            static_tables=config.static_tables,
             device=config.device,
             activation_dtype=config.activation_dtype,
             attention_dtype=config.attention_dtype,
@@ -91,6 +92,7 @@ def __init__(self, theta: Theta, config: LlamaModelConfig):
                 max_seqlen=hp.context_length,
                 device=self.device,
                 use_hf=self.use_hf,
+                static_tables=config.static_tables,
                 tensor_parallelism_size=config.tensor_parallelism_size,
             ),
         )
@@ -124,7 +126,7 @@ def prefill(
         tokens: Union[torch.Tensor, ReplicatedTensor],
         *,
         # [1, 1, batch_seq_len, batch_seq_len]
-        attention_mask: Optional[Union[torch.Tensor, ReplicatedTensor]],
+        attention_mask: Union[torch.Tensor, ReplicatedTensor],
         # [bs, batch_seq_len // block_seq_stride]
         seq_block_ids: Union[torch.Tensor, ReplicatedTensor],
         cache_state: list[Union[torch.Tensor, SplitPrimitiveTensor]],

sharktank/tests/evaluate/perplexity_iree_test.py

@@ -34,7 +34,6 @@ def setUp(self):
         with open(self.baseline_perplexity_scores, "r") as f:
             self.baseline_perplexity = json.load(f)
 
-    @pytest.mark.xfail(reason="Runtime segfault", run=False)
     def test_llama3_8B_f16_decomposed(self):
 
         # Llama 3.1 8B decomposed