[CPU] enable fused_sigmoid_mul on CPU device (#29378)

python/sglang/srt/models/qwen3_5.py

@@ -142,6 +142,9 @@ if _is_cuda:
         fused_qk_gemma_rmsnorm_rope_gate,
     )
 
+if _is_cpu:
+    fused_sigmoid_mul = torch.ops.sgl_kernel.fused_sigmoid_mul_cpu
+
 if _is_npu:
     from sgl_kernel_npu.norm.split_qkv_rmsnorm_rope import (
         split_qkvgate_gemma_rmsnorm_rope,
@@ -1023,7 +1026,7 @@ class Qwen3_5AttentionDecoderLayer(nn.Module):
         attn_output = self.attn(q, k, v, forward_batch)
 
         if self.attn_output_gate:
-            if not (_is_npu or _is_cpu):
+            if not _is_npu:
                 attn_output = fused_sigmoid_mul(attn_output, gate, inplace=True)
             else:
                 gate_val = gate.reshape(gate.shape[0], -1) if gate.ndim == 3 else gate

sgl-kernel/csrc/cpu/activation.cpp

@@ -52,6 +52,55 @@ void act_and_mul_kernel_impl(
   });
 }
 
+// input : [num_tokens, dim] contiguous
+// gate : [num_tokens, num_heads, head_dim] 2d or 3d, maybe strided
+template <typename scalar_t>
+void fused_sigmoid_mul_kernel_impl(
+    scalar_t* __restrict__ output,
+    const scalar_t* __restrict__ input,
+    const scalar_t* __restrict__ gate,
+    int64_t num_tokens,
+    int64_t dim,
+    int64_t num_heads,
+    int64_t head_dim,
+    int64_t g_strideT,
+    int64_t g_strideH) {
+  using bVec = at::vec::Vectorized<scalar_t>;
+  using fVec = at::vec::Vectorized<float>;
+
+  constexpr int64_t kVecSize = bVec::size();
+  const fVec one = fVec(1.f);
+  at::parallel_for(0, num_tokens, 0, [&](int64_t begin, int64_t end) {
+    for (int64_t i = begin; i < end; ++i) {
+      const scalar_t* __restrict__ i_ptr = input + i * dim;
+      const scalar_t* __restrict__ g_ptr = gate + i * g_strideT;
+      scalar_t* __restrict__ o_ptr = output + i * dim;
+
+      for (int64_t h = 0; h < num_heads; ++h) {
+        const scalar_t* __restrict__ attn_ptr = i_ptr + h * head_dim;
+        const scalar_t* __restrict__ gate_ptr = g_ptr + h * g_strideH;
+        scalar_t* __restrict__ out_ptr = o_ptr + h * head_dim;
+
+        int64_t d = 0;
+#pragma GCC unroll 4
+        for (; d <= head_dim - kVecSize; d += kVecSize) {
+          auto [x_fvec0, x_fvec1] = load_float_vec2(attn_ptr + d);
+          auto [g_fvec0, g_fvec1] = load_float_vec2(gate_ptr + d);
+          x_fvec0 = x_fvec0 / (one + g_fvec0.neg().exp_u20());
+          x_fvec1 = x_fvec1 / (one + g_fvec1.neg().exp_u20());
+          convert_from_float_ext<scalar_t>(x_fvec0, x_fvec1).store(out_ptr + d);
+        }
+#pragma GCC unroll 4
+        for (; d < head_dim; ++d) {
+          float x_val = static_cast<float>(attn_ptr[d]);
+          float g_val = static_cast<float>(gate_ptr[d]);
+          out_ptr[d] = static_cast<scalar_t>(x_val / (1.f + std::exp(-g_val)));
+        }
+      }
+    }
+  });
+}
+
 }  // anonymous namespace
 
 // input   : {num_tokens, 2 * d}
@@ -130,3 +179,41 @@ at::Tensor gelu_and_mul_cpu(const at::Tensor& input) {
 
   return out;
 }
+
+at::Tensor fused_sigmoid_mul_cpu(at::Tensor& input, const at::Tensor& gate, bool inplace) {
+  CHECK_DIM(2, input);
+  const int64_t gate_dim = gate.dim();
+  TORCH_CHECK(gate_dim == 2 || gate_dim == 3, "gate must be a 2D or 3D tensor");
+  CHECK_CONTIGUOUS(input);
+  CHECK_LAST_DIM_CONTIGUOUS_INPUT(gate);
+
+  const auto st = input.scalar_type();
+  CHECK_EQ(gate.scalar_type(), st);
+
+  int64_t num_tokens = input.size(0);
+  int64_t d = input.size(1);
+
+  const bool is_gate_3d = gate_dim == 3;
+  int64_t num_heads = is_gate_3d ? gate.size(1) : 1;
+  int64_t head_dim = gate.size(-1);
+  CHECK_EQ(gate.size(0), num_tokens);
+  CHECK_EQ(d, num_heads * head_dim);
+
+  int64_t g_strideT = gate.stride(0);
+  int64_t g_strideH = is_gate_3d ? gate.stride(1) : 0;
+
+  at::Tensor out = inplace ? input : at::empty_like(input);
+  AT_DISPATCH_REDUCED_FLOATING_TYPES(st, "fused_sigmoid_mul", [&] {
+    fused_sigmoid_mul_kernel_impl<scalar_t>(
+        out.data_ptr<scalar_t>(),
+        input.data_ptr<scalar_t>(),
+        gate.data_ptr<scalar_t>(),
+        num_tokens,
+        d,
+        num_heads,
+        head_dim,
+        g_strideT,
+        g_strideH);
+  });
+  return out;
+}

sgl-kernel/csrc/cpu/torch_extension_cpu.cpp

@@ -27,6 +27,9 @@ at::Tensor silu_and_mul_cpu(at::Tensor& input);
 at::Tensor gelu_tanh_and_mul_cpu(const at::Tensor& input);
 at::Tensor gelu_and_mul_cpu(const at::Tensor& input);
 
+// fused_sigmoid_mul
+at::Tensor fused_sigmoid_mul_cpu(at::Tensor& input, const at::Tensor& gate, bool inplace);
+
 // l2norm
 at::Tensor l2norm_cpu(at::Tensor& input, double eps);
 
@@ -439,6 +442,8 @@ TORCH_LIBRARY_FRAGMENT(sgl_kernel, m) {
   m.impl("gelu_tanh_and_mul_cpu", torch::kCPU, &gelu_tanh_and_mul_cpu);
   m.def("gelu_and_mul_cpu(Tensor input) -> Tensor");
   m.impl("gelu_and_mul_cpu", torch::kCPU, &gelu_and_mul_cpu);
+  m.def("fused_sigmoid_mul_cpu(Tensor(a!) input, Tensor gate, bool inplace) -> Tensor(a!)");
+  m.impl("fused_sigmoid_mul_cpu", torch::kCPU, &fused_sigmoid_mul_cpu);
 
   // norm
   m.def("rmsnorm_cpu(Tensor input, Tensor weight, float eps) -> Tensor");

test/registered/cpu/test_activation.py

@@ -1,60 +1,74 @@
-import itertools
-import unittest
+import sys
 
+import pytest
 import torch
 from utils import GeluAndMul, SiluAndMul, precision
 
 from sglang.srt.server_args import ServerArgs, set_global_server_args_for_scheduler
 from sglang.test.ci.ci_register import register_cpu_ci
-from sglang.test.test_utils import CustomTestCase
 
 register_cpu_ci(est_time=10, suite="base-b-test-cpu")
 register_cpu_ci(est_time=10, suite="base-b-test-cpu-arm64")
 
 torch.manual_seed(1234)
 
-
-class TestActivation(CustomTestCase):
 M = [128, 129, 257]
 N = [22016, 22018]
-    dtype = [torch.float16, torch.bfloat16]
+DTYPES = [torch.float16, torch.bfloat16]
 
-    def _silu_and_mul_test(self, m, n, dtype):
+
+def _assert_close(ref_out, out):
+    atol = rtol = precision[ref_out.dtype]
+    torch.testing.assert_close(ref_out, out, atol=atol, rtol=rtol)
+
+
+@pytest.mark.parametrize("dtype", DTYPES)
+@pytest.mark.parametrize("n", N)
+@pytest.mark.parametrize("m", M)
+def test_activation(m, n, dtype):
     set_global_server_args_for_scheduler(ServerArgs(model_path="dummy"))
 
     x = torch.randn([m, n], dtype=dtype)
+    _assert_close(SiluAndMul(x), torch.ops.sgl_kernel.silu_and_mul_cpu(x))
 
-        out = torch.ops.sgl_kernel.silu_and_mul_cpu(x)
-        ref_out = SiluAndMul(x)
-
-        atol = rtol = precision[ref_out.dtype]
-        torch.testing.assert_close(ref_out, out, atol=atol, rtol=rtol)
-
-    def _gelu_and_mul_test(self, m, n, dtype):
     x = torch.randn([m, n], dtype=dtype)
+    _assert_close(
+        GeluAndMul(x, approximate="none"), torch.ops.sgl_kernel.gelu_and_mul_cpu(x)
+    )
 
-        out = torch.ops.sgl_kernel.gelu_and_mul_cpu(x)
-        ref_out = GeluAndMul(x, approximate="none")
-
-        atol = rtol = precision[ref_out.dtype]
-        torch.testing.assert_close(ref_out, out, atol=atol, rtol=rtol)
-
-    def _gelu_tanh_and_mul_test(self, m, n, dtype):
     x = torch.randn([m, n], dtype=dtype)
+    _assert_close(
+        GeluAndMul(x, approximate="tanh"),
+        torch.ops.sgl_kernel.gelu_tanh_and_mul_cpu(x),
+    )
 
-        out = torch.ops.sgl_kernel.gelu_tanh_and_mul_cpu(x)
-        ref_out = GeluAndMul(x, approximate="tanh")
 
-        atol = rtol = precision[ref_out.dtype]
-        torch.testing.assert_close(ref_out, out, atol=atol, rtol=rtol)
+@pytest.mark.parametrize("gate_3d", [False, True])
+@pytest.mark.parametrize("dtype", DTYPES)
+@pytest.mark.parametrize("head_dim", [256])
+@pytest.mark.parametrize("num_heads", [16])
+@pytest.mark.parametrize("m", [1, 17, 128])
+def test_fused_sigmoid_mul(m, num_heads, head_dim, dtype, gate_3d):
+    x = torch.randn([m, num_heads * head_dim], dtype=dtype)
+    if gate_3d:
+        gate_storage = torch.randn([m, num_heads, head_dim * 2], dtype=dtype)
+        gate = gate_storage[..., :head_dim]
+        assert not gate.is_contiguous()
+    else:
+        gate = torch.randn_like(x)
 
-    def test_activation(self):
-        for params in itertools.product(self.M, self.N, self.dtype):
-            with self.subTest(m=params[0], n=params[1], dtype=params[2]):
-                self._silu_and_mul_test(*params)
-                self._gelu_and_mul_test(*params)
-                self._gelu_tanh_and_mul_test(*params)
+    gate_ref = gate.reshape(m, -1) if gate_3d else gate
+    _assert_close(
+        x * torch.sigmoid(gate_ref),
+        torch.ops.sgl_kernel.fused_sigmoid_mul_cpu(x, gate, False),
+    )
+
+    x_inplace = x.clone()
+    ref_inplace = x_inplace * torch.sigmoid(gate_ref)
+    out_inplace = torch.ops.sgl_kernel.fused_sigmoid_mul_cpu(x_inplace, gate, True)
+    assert out_inplace.data_ptr() == x_inplace.data_ptr()
+    _assert_close(ref_inplace, x_inplace)
 
 
 if __name__ == "__main__":
-    unittest.main()
+    sys.exit(pytest.main([__file__]))