modify in pad_op and pad_constant

paddle/fluid/operators/pad_constant_like_op.cc

@@ -42,7 +42,10 @@ class PadConstantLikeOp : public framework::OperatorWithKernel {
       if ((!ctx->IsRuntime()) && ((x_dim[i] == -1) || (y_dim[i] == -1))) {
         continue;
       } else {
-        PADDLE_ENFORCE_GE(x_dim[i], y_dim[i]);
+        PADDLE_ENFORCE_GE(
+            x_dim[i], y_dim[i],
+            "expected X_dim[i] >= Y_dim[i], but received %d < %d for dim %d",
+            x_dim[i], y_dim[i], i);
       }
     }
 
@@ -171,7 +174,10 @@ class PadConstantLikeOpGrad : public framework::OperatorWithKernel {
         if ((!ctx->IsRuntime()) && ((dout_dim[i] == -1) || (y_dim[i] == -1))) {
           continue;
         } else {
-          PADDLE_ENFORCE_GE(dout_dim[i], y_dim[i]);
+          PADDLE_ENFORCE_GE(dout_dim[i], y_dim[i],
+                            "expected Out_dim[i] >= Y_dim[i], but received %d "
+                            "< %d for dim %d",
+                            dout_dim[i], y_dim[i], i);
         }
       }
     }

paddle/fluid/operators/pad_op.cc

@@ -34,6 +34,9 @@ class PadOp : public framework::OperatorWithKernel {
     PADDLE_ENFORCE_EQ(x_dim.size() * 2, int64_t(paddings.size()),
                       "Size of paddings should be equal to 2 * dimension size "
                       "of input tensor.");
+    for (size_t i = 0; i < paddings.size(); ++i) {
+      PADDLE_ENFORCE_GE(paddings[i], 0, "paddings should >= 0.");
+    }
     std::vector<int64_t> out_dims(x_dim.size());
     for (int i = 0; i < x_dim.size(); ++i) {
       if ((!ctx->IsRuntime()) && (x_dim[i] == -1)) {