torch/lib/THNN/generic/Sigmoid.c

#ifndef TH_GENERIC_FILE
#define TH_GENERIC_FILE "generic/Sigmoid.c"
#else

void THNN_(Sigmoid_updateOutput)(
          THNNState *state,
          THTensor *input,
          THTensor *output)
{
  THTensor_(sigmoid)(output, input);
}

void THNN_(Sigmoid_updateGradInput)(
          THNNState *state,
          THTensor *input,
          THTensor *gradOutput,
          THTensor *gradInput,
          THTensor *output)
{
  THNN_CHECK_NELEMENT(output, gradOutput);
  THTensor_(resizeAs)(gradInput, output);
  TH_TENSOR_APPLY3(real, gradInput, real, gradOutput, real, output,
    real z = *output_data;
    *gradInput_data = *gradOutput_data * (1. - z) * z;
  );
}

#endif