grouped conv (#8)

Summary:
Pull Request resolved: https://github.com/pytorch/FBGEMM/pull/8

This is the second diff of the stack that implements grouped convolution.

Reviewed By: jianyuh

Differential Revision: D13048844

fbshipit-source-id: 7f1e8c1412e499cc76ca788004bb8e41c8f0308c

1 files changed, 10 insertions, 0 deletions

diff --git a/include/fbgemm/ConvUtils.h b/include/fbgemm/ConvUtils.h
index 667998c..fa6967a 100644
--- a/include/fbgemm/ConvUtils.h
+++ b/include/fbgemm/ConvUtils.h
@@ -53,6 +53,16 @@ struct conv_param_t {
         K(k),
         stride(strd),
         pad(pd) {
+    if (ic % g != 0) {
+      throw std::runtime_error(
+          "groups = " + std::to_string(g) +
+          " does not divide number of input channels = " + std::to_string(ic));
+    }
+    if (oc % g != 0) {
+      throw std::runtime_error(
+          "groups = " + std::to_string(g) +
+          " does not divide number of output channels = " + std::to_string(oc));
+    }
     for (int d = 0; d < SPATIAL_DIM; ++d) {
       dilation[d] = 1;
       IN_DIMP[d] = IN_DIM[d] + pad[d] + pad[SPATIAL_DIM + d];