Revert change from #532 due to unsafe use of static buffer

see #1844

driver/level2/gemv_thread.c

@@ -62,11 +62,6 @@
 #endif
 #endif
 
-#ifndef TRANSA
-#define Y_DUMMY_NUM 1024
-static FLOAT y_dummy[Y_DUMMY_NUM];
-#endif
-
 static int gemv_kernel(blas_arg_t *args, BLASLONG *range_m, BLASLONG *range_n, FLOAT *dummy1, FLOAT *buffer, BLASLONG pos){
 
   FLOAT *a, *x, *y;
@@ -104,15 +99,10 @@ static int gemv_kernel(blas_arg_t *args, BLASLONG *range_m, BLASLONG *range_n, F
     a += n_from * lda  * COMPSIZE;
 #ifdef TRANSA
     y += n_from * incy * COMPSIZE;
-#else
-    //for split matrix row (n) direction and vector x of gemv_n
-    x += n_from * incx * COMPSIZE;
-    //store partial result for every thread
-    y += (m_to - m_from) * 1 * COMPSIZE * pos;
 #endif
   }
 
-  //fprintf(stderr, "M_From = %d  M_To = %d  N_From = %d  N_To = %d POS=%d\n", m_from, m_to, n_from, n_to, pos);
+  //  fprintf(stderr, "M_From = %d  M_To = %d  N_From = %d  N_To = %d\n", m_from, m_to, n_from, n_to);
 
   GEMV(m_to - m_from, n_to - n_from, 0,
        *((FLOAT *)args -> alpha + 0),
@@ -136,10 +126,6 @@ int CNAME(BLASLONG m, BLASLONG n, FLOAT *alpha, FLOAT *a, BLASLONG lda, FLOAT *x
 
   BLASLONG width, i, num_cpu;
 
-#ifndef TRANSA
-  int split_x=0;
-#endif
-
 #ifdef SMP
 #ifndef COMPLEX
 #ifdef XDOUBLE
@@ -212,58 +198,6 @@ int CNAME(BLASLONG m, BLASLONG n, FLOAT *alpha, FLOAT *a, BLASLONG lda, FLOAT *x
     i -= width;
   }
 
-#ifndef TRANSA
-  //try to split matrix on row direction and x.
-  //Then, reduction.
-  if (num_cpu < nthreads) {
-
-    //too small to split or bigger than the y_dummy buffer.
-    double MN = (double) m * (double) n;
-    if ( MN <= (24.0 * 24.0  * (double) (GEMM_MULTITHREAD_THRESHOLD*GEMM_MULTITHREAD_THRESHOLD))
-	 || m*COMPSIZE*nthreads > Y_DUMMY_NUM)
-      goto Outer;
-
-    num_cpu  = 0;
-    range[0] = 0;
-
-    memset(y_dummy, 0, sizeof(FLOAT) * m * COMPSIZE * nthreads);
-
-    args.ldc = 1;
-    args.c = (void *)y_dummy;
-
-    //split on row (n) and x
-    i=n;
-    split_x=1;
-    while (i > 0){
-
-      width  = blas_quickdivide(i + nthreads - num_cpu - 1, nthreads - num_cpu);
-      if (width < 4) width = 4;
-      if (i < width) width = i;
-
-      range[num_cpu + 1] = range[num_cpu] + width;
-
-      queue[num_cpu].mode    = mode;
-      queue[num_cpu].routine = gemv_kernel;
-      queue[num_cpu].args    = &args;
-
-      queue[num_cpu].position = num_cpu;
-
-      queue[num_cpu].range_m = NULL;
-      queue[num_cpu].range_n = &range[num_cpu];
-
-      queue[num_cpu].sa      = NULL;
-      queue[num_cpu].sb      = NULL;
-      queue[num_cpu].next    = &queue[num_cpu + 1];
-
-      num_cpu ++;
-      i -= width;
-    }
-
-  }
-
-  Outer:
-#endif
-
   if (num_cpu) {
     queue[0].sa = NULL;
     queue[0].sb = buffer;
@@ -272,21 +206,5 @@ int CNAME(BLASLONG m, BLASLONG n, FLOAT *alpha, FLOAT *a, BLASLONG lda, FLOAT *x
     exec_blas(num_cpu, queue);
   }
 
-#ifndef TRANSA
-  if(split_x==1){
-    //reduction
-    for(i=0; i<num_cpu; i++){
-
-      int j;
-      for(j=0; j<m; j++){
-	y[j*incy*COMPSIZE] +=y_dummy[i*m*COMPSIZE + j*COMPSIZE];
-#ifdef COMPLEX
-	y[j*incy*COMPSIZE+1] +=y_dummy[i*m*COMPSIZE + j*COMPSIZE+1];
-#endif
-      }
-    }
-  }
-#endif
-
   return 0;
 }