delete ch_four contorl in conv_3x3_dw. test=develop (#4435)

lite/backends/arm/math/conv3x3s1px_depthwise_fp32.cc

@@ -645,7 +645,6 @@ void conv_3x3s1_depthwise_fp32_bias(const float* i_data,
   bool flag_bias = param.bias != nullptr;
 
   /// get workspace
-  LOG(INFO) << "conv_3x3s1_depthwise_fp32_bias: ";
   float* ptr_zero = ctx->workspace_data<float>();
   memset(ptr_zero, 0, sizeof(float) * win_round);
   float* ptr_write = ptr_zero + win_round;

lite/backends/arm/math/conv_impl.cc

@@ -620,10 +620,8 @@ void conv_depthwise_3x3_fp32(const void* din,
   int pad = pad_w;
   bool flag_bias = param.bias != nullptr;
   bool pads_less = ((paddings[1] < 2) && (paddings[3] < 2));
-  bool ch_four = ch_in <= 4 * w_in;
   if (stride == 1) {
-    if (ch_four && pads_less && (pad_h == pad_w) &&
-        (pad < 2)) {  // support pad = [0, 1]
+    if (pads_less && (pad_h == pad_w) && (pad < 2)) {  // support pad = [0, 1]
       conv_depthwise_3x3s1_fp32(reinterpret_cast<const float*>(din),
                                 reinterpret_cast<float*>(dout),
                                 num,
@@ -656,8 +654,7 @@ void conv_depthwise_3x3_fp32(const void* din,
                                 ctx);
     }
   } else if (stride == 2) {
-    if (ch_four && pads_less && pad_h == pad_w &&
-        (pad < 2)) {  // support pad = [0, 1]
+    if (pads_less && pad_h == pad_w && (pad < 2)) {  // support pad = [0, 1]
       conv_depthwise_3x3s2_fp32(reinterpret_cast<const float*>(din),
                                 reinterpret_cast<float*>(dout),
                                 num,

lite/kernels/arm/conv_depthwise.cc

@@ -32,11 +32,10 @@ void DepthwiseConv<PRECISION(kFloat), PRECISION(kFloat)>::PrepareForRun() {
   auto hin = param.x->dims()[2];
   auto win = param.x->dims()[3];
   auto paddings = *param.paddings;
-  bool ch_four = channel <= 4 * win;
   // select dw conv kernel
   if (kw == 3) {
     bool pads_less = ((paddings[1] < 2) && (paddings[3] < 2));
-    if (ch_four && pads_less && paddings[0] == paddings[2] &&
+    if (pads_less && paddings[0] == paddings[2] &&
         (paddings[0] == 0 || paddings[0] == 1)) {
       flag_trans_weights_ = false;
     } else {