fix blas dot and add cblas scal

paddle/fluid/operators/math/blas.h

@@ -156,6 +156,9 @@ class Blas {
   template <typename T>
   T DOT(int n, const T* x, const T* y) const;
 
+  template <typename T>
+  void SCAL(int n, const T a, const T* x) const;
+
   template <typename T>
   void BatchedGEMM(CBLAS_TRANSPOSE transA, CBLAS_TRANSPOSE transB, int M, int N,
                    int K, T alpha, const T* A, const T* B, T beta, T* C,

paddle/fluid/operators/math/blas_impl.h

@@ -78,6 +78,11 @@ struct CBlas<float> {
     return platform::dynload::cblas_sdot(args...);
   }
 
+  template <typename... ARGS>
+  static void SCAL(ARGS... args) {
+    platform::dynload::cblas_sscal(args...);
+  }
+
   template <typename... ARGS>
   static void GEMM_BATCH(ARGS... args) {
     platform::dynload::cblas_sgemm_batch(args...);
@@ -148,6 +153,11 @@ struct CBlas<double> {
     return platform::dynload::cblas_ddot(args...);
   }
 
+  template <typename... ARGS>
+  static void SCAL(ARGS... args) {
+    platform::dynload::cblas_dscal(args...);
+  }
+
   template <typename... ARGS>
   static void GEMM_BATCH(ARGS... args) {
     platform::dynload::cblas_dgemm_batch(args...);
@@ -221,6 +231,7 @@ struct CBlas<platform::float16> {
   }
   static void VMUL(...) { PADDLE_THROW("float16 VMUL not supported on CPU"); }
   static void DOT(...) { PADDLE_THROW("float16 DOT not supported on CPU"); };
+  static void SCAL(...) { PADDLE_THROW("float16 SCAL not supported on CPU"); };
 #ifdef PADDLE_WITH_MKLML
   static void GEMM_BATCH(...) {
     PADDLE_THROW("float16 GEMM_BATCH not supported on CPU");
@@ -367,7 +378,7 @@ template <>
 template <typename T>
 T Blas<platform::CPUDeviceContext>::DOT(int n, const T *x, const T *y) const {
 #ifdef PADDLE_WITH_MKLML
-  return CBlas<T>::DOT(n, x, y);
+  return CBlas<T>::DOT(n, x, 1, y, 1);
 #else
   // try to find if openblas support cblas_dot
   T sum = 0;
@@ -378,6 +389,20 @@ T Blas<platform::CPUDeviceContext>::DOT(int n, const T *x, const T *y) const {
 #endif
 }
 
+template <>
+template <typename T>
+void Blas<platform::CPUDeviceContext>::SCAL(int n, const T a,
+                                            const T *x) const {
+#ifdef PADDLE_WITH_MKLML
+  CBlas<T>::SCAL(n, a, x, 1);
+#else
+  // try to find if openblas support cblas_scal
+  for (int i = 0; i < n; ++i) {
+    x[i] = a * x[i];
+  }
+#endif
+}
+
 template <>
 template <typename T>
 void Blas<platform::CPUDeviceContext>::GEMV(bool trans_a, int M, int N, T alpha,

paddle/fluid/platform/dynload/mklml.h

@@ -68,6 +68,8 @@ extern void* mklml_dso_handle;
   __macro(cblas_dgemm_batch);       \
   __macro(cblas_sdot);              \
   __macro(cblas_ddot);              \
+  __macro(cblas_sscal);             \
+  __macro(cblas_dscal);             \
   __macro(vsAdd);                   \
   __macro(vdAdd);                   \
   __macro(vsMul);                   \