implement HEMV level2 blas routine

1 files changed, 36 insertions, 1 deletions

diff --git a/blas/level2_impl.h b/blas/level2_impl.h
index 92d058a5c..87a4d04df 100644
--- a/blas/level2_impl.h
+++ b/blas/level2_impl.h
@@ -500,8 +500,43 @@ int EIGEN_BLAS_FUNC(spr2)(char *uplo, int *n, RealScalar *alpha, RealScalar *x,
   *  where alpha and beta are scalars, x and y are n element vectors and
   *  A is an n by n hermitian matrix.
   */
-int EIGEN_BLAS_FUNC(hemv)(char *uplo, int *n, RealScalar *palpha, RealScalar *pa, int *lda, RealScalar *x, int *incx, RealScalar *pbeta, RealScalar *y, int *incy)
+int EIGEN_BLAS_FUNC(hemv)(char *uplo, int *n, RealScalar *palpha, RealScalar *pa, int *lda, RealScalar *px, int *incx, RealScalar *pbeta, RealScalar *py, int *incy)
 {
+  Scalar* a = reinterpret_cast<Scalar*>(pa);
+  Scalar* x = reinterpret_cast<Scalar*>(px);
+  Scalar* y = reinterpret_cast<Scalar*>(py);
+  Scalar alpha  = *reinterpret_cast<Scalar*>(palpha);
+  Scalar beta   = *reinterpret_cast<Scalar*>(pbeta);
+
+  // check arguments
+  int info = 0;
+  if(UPLO(*uplo)==INVALID)        info = 1;
+  else if(*n<0)                   info = 2;
+  else if(*lda<std::max(1,*n))    info = 5;
+  else if(*incx==0)               info = 7;
+  else if(*incy==0)               info = 10;
+  if(info)
+    return xerbla_(SCALAR_SUFFIX_UP"HEMV ",&info,6);
+
+  if(*n==0)
+    return 1;
+
+  Scalar* actual_x = get_compact_vector(x,*n,*incx);
+  Scalar* actual_y = get_compact_vector(y,*n,*incy);
+
+  if(beta!=Scalar(1))
+    vector(actual_y, *n) *= beta;
+
+  if(alpha!=Scalar(0))
+  {
+    // TODO performs a direct call to the underlying implementation function
+         if(UPLO(*uplo)==UP) vector(actual_y,*n).noalias() += matrix(a,*n,*n,*lda).selfadjointView<Upper>() * (alpha * vector(actual_x,*n));
+    else if(UPLO(*uplo)==LO) vector(actual_y,*n).noalias() += matrix(a,*n,*n,*lda).selfadjointView<Lower>() * (alpha * vector(actual_x,*n));
+  }
+  
+  if(actual_x!=x) delete[] actual_x;
+  if(actual_y!=y) delete[] copy_back(actual_y,y,*n,*incy);
+
   return 1;
 }