pnnx fuse t5-layernorm as rmsnorm

tools/pnnx/src/CMakeLists.txt

@@ -369,6 +369,7 @@ set(pnnx_pass_level5_SRCS
     pass_level5/fuse_pixel_unshuffle.cpp
     pass_level5/fuse_layernorm.cpp
     pass_level5/fuse_multiheadattention.cpp
+    pass_level5/fuse_rmsnorm.cpp
     pass_level5/fuse_scaled_dot_product_attention.cpp
     pass_level5/fuse_select_to_unbind.cpp
     pass_level5/fuse_silu.cpp

tools/pnnx/src/pass_level5.cpp

@@ -44,6 +44,7 @@
 #include "pass_level5/fuse_multiheadattention.h"
 #include "pass_level5/fuse_pad_conv1d.h"
 #include "pass_level5/fuse_pad_conv2d.h"
+#include "pass_level5/fuse_rmsnorm.h"
 #include "pass_level5/fuse_scaled_dot_product_attention.h"
 #include "pass_level5/fuse_select_to_unbind.h"
 #include "pass_level5/fuse_silu.h"
@@ -145,6 +146,7 @@ void pass_level5(Graph& g, const std::set<std::string>& foldable_constants, cons
 
     fuse_channel_shuffle(g);
     fuse_layernorm(g);
+    fuse_rmsnorm(g);
     fuse_multiheadattention(g);
     fuse_scaled_dot_product_attention(g);
 

tools/pnnx/src/pass_level5/fuse_rmsnorm.cpp

@@ -0,0 +1,79 @@
+// Tencent is pleased to support the open source community by making ncnn available.
+//
+// Copyright (C) 2024 THL A29 Limited, a Tencent company. All rights reserved.
+//
+// Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
+// in compliance with the License. You may obtain a copy of the License at
+//
+// https://opensource.org/licenses/BSD-3-Clause
+//
+// Unless required by applicable law or agreed to in writing, software distributed
+// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+// CONDITIONS OF ANY KIND, either express or implied. See the License for the
+// specific language governing permissions and limitations under the License.
+
+#include "fuse_rmsnorm.h"
+
+#include "pass_level2.h"
+
+#include <math.h>
+#include <string.h>
+
+namespace pnnx {
+
+class fuse_rmsnorm_pass : public GraphRewriterPass
+{
+public:
+    const char* match_pattern_graph() const
+    {
+        return R"PNNXIR(7767517
+6 5
+pnnx.Input              input       0 1 input
+pnnx.Attribute          op_0        0 1 weight @data #weight=(%c)f32
+pnnx.Expression         op_1        1 1 input sq expr=pow(@0,2)
+torch.mean              op_2        1 1 sq sqmean dim=(-1) keepdim=True
+pnnx.Expression         op_3        3 1 weight input sqmean out expr=mul(@0,mul(@1,rsqrt(add(@2,%eps))))
+pnnx.Output             output      1 0 out
+)PNNXIR";
+    }
+
+
+    const char* replace_pattern_graph() const
+    {
+        return R"PNNXIR(7767517
+3 2
+pnnx.Input              input       0 1 input
+nn.RMSNorm              rmsnorm     1 1 input out elementwise_affine=True eps=%eps normalized_shape=(%c) @weight=%op_0.data
+pnnx.Output             output      1 0 out
+)PNNXIR";
+    }
+};
+
+class fuse_rmsnorm_pass_onnx : public fuse_rmsnorm_pass
+{
+public:
+    const char* match_pattern_graph() const
+    {
+        return R"PNNXIR(7767517
+6 5
+pnnx.Input              input       0 1 input
+pnnx.Attribute          op_0        0 1 weight @data #weight=(%c)f32
+pnnx.Expression         op_1        1 1 input sq expr=pow(@0,2.000000e+00)
+torch.mean              op_2        1 1 sq sqmean dim=(-1) keepdim=True
+pnnx.Expression         op_3        3 1 weight input sqmean out expr=mul(@0,mul(@1,div(1.000000e+00,sqrt(add(@2,%eps)))))
+pnnx.Output             output      1 0 out
+)PNNXIR";
+    }
+};
+
+void fuse_rmsnorm(Graph& graph)
+{
+    fuse_rmsnorm_pass a;
+    fuse_rmsnorm_pass_onnx b;
+    int opindex = 0;
+
+    pnnx_graph_rewrite(graph, &a, opindex);
+    pnnx_graph_rewrite(graph, &b, opindex);
+}
+
+} // namespace pnnx

tools/pnnx/src/pass_level5/fuse_rmsnorm.h

@@ -0,0 +1,21 @@
+// Tencent is pleased to support the open source community by making ncnn available.
+//
+// Copyright (C) 2024 THL A29 Limited, a Tencent company. All rights reserved.
+//
+// Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
+// in compliance with the License. You may obtain a copy of the License at
+//
+// https://opensource.org/licenses/BSD-3-Clause
+//
+// Unless required by applicable law or agreed to in writing, software distributed
+// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+// CONDITIONS OF ANY KIND, either express or implied. See the License for the
+// specific language governing permissions and limitations under the License.
+
+#include "ir.h"
+
+namespace pnnx {
+
+void fuse_rmsnorm(Graph& graph);
+
+} // namespace pnnx

tools/pnnx/tests/CMakeLists.txt

@@ -346,6 +346,7 @@ pnnx_add_test(pnnx_fuse_input_unpack)
 pnnx_add_test(pnnx_fuse_layernorm)
 pnnx_add_test(pnnx_fuse_linear_batchnorm1d)
 pnnx_add_test(pnnx_fuse_multiheadattention)
+pnnx_add_test(pnnx_fuse_rmsnorm)
 pnnx_add_test(pnnx_fuse_scaled_dot_product_attention)
 pnnx_add_test(pnnx_fuse_select_to_unbind)
 pnnx_add_test(pnnx_fuse_slice_to_tensor_split)

tools/pnnx/tests/test_pnnx_fuse_rmsnorm.py

@@ -0,0 +1,73 @@
+# Tencent is pleased to support the open source community by making ncnn available.
+#
+# Copyright (C) 2024 THL A29 Limited, a Tencent company. All rights reserved.
+#
+# Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
+# in compliance with the License. You may obtain a copy of the License at
+#
+# https://opensource.org/licenses/BSD-3-Clause
+#
+# Unless required by applicable law or agreed to in writing, software distributed
+# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+# CONDITIONS OF ANY KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations under the License.
+
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+
+class T5LayerNorm(nn.Module):
+    def __init__(self, hidden_size, eps=1e-6):
+        super().__init__()
+        self.weight = nn.Parameter(torch.rand(hidden_size))
+        self.variance_epsilon = eps
+
+    def forward(self, x):
+        variance = x.pow(2).mean(-1, keepdim=True)
+        x = x * torch.rsqrt(variance + self.variance_epsilon)
+        return self.weight * x
+
+class Model(nn.Module):
+    def __init__(self):
+        super(Model, self).__init__()
+
+        self.rmsn_0 = T5LayerNorm(26)
+        self.rmsn_1 = T5LayerNorm(21)
+
+    def forward(self, x, y):
+        x = self.rmsn_0(x)
+        y = self.rmsn_1(y)
+        return x, y
+
+def test():
+    net = Model()
+    net.eval()
+
+    torch.manual_seed(0)
+    x = torch.rand(1, 64, 26)
+    y = torch.rand(3, 15, 15, 21)
+
+    a0, a1 = net(x, y)
+
+    # export onnx
+    torch.onnx.export(net, (x,y), "test.onnx")
+
+    # export torchscript
+    mod = torch.jit.trace(net, (x, y))
+    mod.save("test_pnnx_fuse_rmsnorm.pt")
+
+    # torchscript to pnnx
+    import os
+    os.system("../src/pnnx test_pnnx_fuse_rmsnorm.pt inputshape=[1,64,26],[3,15,15,21]")
+
+    # pnnx inference
+    import test_pnnx_fuse_rmsnorm_pnnx
+    b0, b1 = test_pnnx_fuse_rmsnorm_pnnx.test_inference()
+
+    return torch.allclose(a0, b0, 1e-4, 1e-4) and torch.allclose(a1, b1, 1e-4, 1e-4)
+
+if __name__ == "__main__":
+    if test():
+        exit(0)
+    else:
+        exit(1)