diff --git a/modules/nsf_hifigan/models.py b/modules/nsf_hifigan/models.py
index a77eb0a38..cc21039f7 100644
--- a/modules/nsf_hifigan/models.py
+++ b/modules/nsf_hifigan/models.py
@@ -130,41 +130,20 @@ def _f02uv(self, f0):
         uv = uv * (f0 > self.voiced_threshold)
         return uv
 
-    def _f02sine(self, f0_values, upp):
-        """ f0_values: (batchsize, length, dim)
+    def _f02sine(self, f0, upp):
+        """ f0: (batchsize, length, dim)
             where dim indicates fundamental tone and overtones
         """
-        rad_values = (f0_values / self.sampling_rate).fmod(1.)  # %1意味着n_har的乘积无法后处理优化
-        rand_ini = torch.rand(1, self.dim, device=f0_values.device)
-        rand_ini[:, 0] = 0
-        rad_values[:, 0, :] += rand_ini
-        is_half = rad_values.dtype is not torch.float32
-        tmp_over_one = torch.cumsum(rad_values.double(), 1)  # % 1  #####%1意味着后面的cumsum无法再优化
-        if is_half:
-            tmp_over_one = tmp_over_one.half()
-        else:
-            tmp_over_one = tmp_over_one.float()
-        tmp_over_one *= upp
-        tmp_over_one = F.interpolate(
-            tmp_over_one.transpose(2, 1), scale_factor=upp,
-            mode='linear', align_corners=True
-        ).transpose(2, 1)
-        rad_values = F.interpolate(rad_values.transpose(2, 1), scale_factor=upp, mode='nearest').transpose(2, 1)
-        tmp_over_one = tmp_over_one.fmod(1.)
-        diff = F.conv2d(
-            tmp_over_one.unsqueeze(1), torch.FloatTensor([[[[-1.], [1.]]]]).to(tmp_over_one.device),
-            stride=(1, 1), padding=0, dilation=(1, 1)
-        ).squeeze(1)  # Equivalent to torch.diff, but able to export ONNX
-        cumsum_shift = (diff < 0).double()
-        cumsum_shift = torch.cat((
-            torch.zeros((1, 1, self.dim), dtype=torch.double).to(f0_values.device),
-            cumsum_shift
-        ), dim=1)
-        sines = torch.sin(torch.cumsum(rad_values.double() + cumsum_shift, dim=1) * 2 * np.pi)
-        if is_half:
-            sines = sines.half()
-        else:
-            sines = sines.float()
+        rad = f0 / self.sampling_rate * torch.arange(1, upp + 1, device=f0.device)
+        rad2 = torch.fmod(rad[..., -1:].float() + 0.5, 1.0) - 0.5
+        rad_acc = rad2.cumsum(dim=1).fmod(1.0).to(f0)
+        rad += F.pad(rad_acc, (0, 0, 1, -1))
+        rad = rad.reshape(f0.shape[0], -1, 1)
+        rad = torch.multiply(rad, torch.arange(1, self.dim + 1, device=f0.device).reshape(1, 1, -1))
+        rand_ini = torch.rand(1, 1, self.dim, device=f0.device)
+        rand_ini[..., 0] = 0
+        rad += rand_ini
+        sines = torch.sin(2 * np.pi * rad)
         return sines
 
     @torch.no_grad()
@@ -176,8 +155,7 @@ def forward(self, f0, upp):
         output uv: tensor(batchsize=1, length, 1)
         """
         f0 = f0.unsqueeze(-1)
-        fn = torch.multiply(f0, torch.arange(1, self.dim + 1, device=f0.device).reshape((1, 1, -1)))
-        sine_waves = self._f02sine(fn, upp) * self.sine_amp
+        sine_waves = self._f02sine(f0, upp) * self.sine_amp
         uv = (f0 > self.voiced_threshold).float()
         uv = F.interpolate(uv.transpose(2, 1), scale_factor=upp, mode='nearest').transpose(2, 1)
         noise_amp = uv * self.noise_std + (1 - uv) * self.sine_amp / 3