Merge pull request PaddlePaddle#41 from lifeiteng/master

avoid repeated exp() calculation
NKNaN · Jul 1, 2016 · 19547b5 · 19547b5
2 parents e80803b + bf78d35
commit 19547b5
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/include/detail/cpu_ctc.h b/include/detail/cpu_ctc.h
@@ -168,11 +168,13 @@ CpuCTC<ProbT>::softmax(const ProbT* const activations, ProbT* probs,
                 max_activation = std::max(max_activation, activations[r + col_offset]);
 
             ProbT denom = ProbT(0.);
-            for(int r = 0; r < alphabet_size_; ++r)
-                denom += std::exp(activations[r + col_offset] - max_activation);
+            for(int r = 0; r < alphabet_size_; ++r) {
+                probs[r + col_offset] = std::exp(activations[r + col_offset] - max_activation);
+                denom += probs[r + col_offset];
+            }
 
             for(int r = 0; r < alphabet_size_; ++r) {
-                probs[r + col_offset] = std::exp(activations[r + col_offset] - max_activation) / denom;
+                probs[r + col_offset] /= denom;
             }
         }
     }