/*********************************************************************/
/* Copyright 2009, 2010 The University of Texas at Austin.           */
/* All rights reserved.                                              */
/*                                                                   */
/* Redistribution and use in source and binary forms, with or        */
/* without modification, are permitted provided that the following   */
/* conditions are met:                                               */
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/*      copyright notice, this list of conditions and the following  */
/*      disclaimer.                                                  */
/*                                                                   */
/*   2. Redistributions in binary form must reproduce the above      */
/*      copyright notice, this list of conditions and the following  */
/*      disclaimer in the documentation and/or other materials       */
/*      provided with the distribution.                              */
/*                                                                   */
/*    THIS  SOFTWARE IS PROVIDED  BY THE  UNIVERSITY OF  TEXAS AT    */
/*    AUSTIN  ``AS IS''  AND ANY  EXPRESS OR  IMPLIED WARRANTIES,    */
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/* documentation are those of the authors and should not be          */
/* interpreted as representing official policies, either expressed   */
/* or implied, of The University of Texas at Austin.                 */
/*********************************************************************/

#include <stdio.h>
#include "common.h"
#include "l1param.h"
#ifdef FUNCTION_PROFILE
#include "functable.h"
#endif

#ifdef XDOUBLE
#define ERROR_NAME "QGEMV "
#elif defined(DOUBLE)
#define ERROR_NAME "DGEMV "
#else
#define ERROR_NAME "SGEMV "
#endif

#ifdef SMP
static int (*gemv_thread[])(BLASLONG, BLASLONG, FLOAT, FLOAT *, BLASLONG,  FLOAT * , BLASLONG, FLOAT *, BLASLONG, FLOAT *, int) = {
#ifdef XDOUBLE
  qgemv_thread_n, qgemv_thread_t,
#elif defined DOUBLE
  dgemv_thread_n, dgemv_thread_t,
#else
  sgemv_thread_n, sgemv_thread_t,
#endif
};
#endif

#ifndef CBLAS

void NAME(char *TRANS, blasint *M, blasint *N,
	   FLOAT *ALPHA, FLOAT *a, blasint *LDA,
	   FLOAT *x, blasint *INCX,
	   FLOAT *BETA, FLOAT *y, blasint *INCY){

  char trans = *TRANS;
  blasint m = *M;
  blasint n = *N;
  blasint lda = *LDA;
  blasint incx = *INCX;
  blasint incy = *INCY;
  FLOAT alpha = *ALPHA;
  FLOAT beta  = *BETA;
  FLOAT *buffer;
  int buffer_size;
#ifdef SMP
  int nthreads;
#endif

  int (*gemv[])(BLASLONG, BLASLONG, BLASLONG, FLOAT, FLOAT *, BLASLONG,  FLOAT * , BLASLONG, FLOAT *, BLASLONG, FLOAT *) = {
    GEMV_N, GEMV_T,
  };

  blasint info;
  blasint lenx, leny;
  blasint i;

  PRINT_DEBUG_NAME;

  TOUPPER(trans);

  info = 0;

  i = -1;

  if (trans == 'N') i = 0;
  if (trans == 'T') i = 1;
  if (trans == 'R') i = 0;
  if (trans == 'C') i = 1;

  if (incy == 0)	info = 11;
  if (incx == 0)	info = 8;
  if (lda < MAX(1, m))	info = 6;
  if (n < 0)		info = 3;
  if (m < 0)		info = 2;
  if (i < 0)          info = 1;

  trans = i;

  if (info != 0){
    BLASFUNC(xerbla)(ERROR_NAME, &info, sizeof(ERROR_NAME));
    return;
  }

#else

void CNAME(enum CBLAS_ORDER order,
	   enum CBLAS_TRANSPOSE TransA,
	   blasint m, blasint n,
	   FLOAT alpha,
	   FLOAT  *a, blasint lda,
	   FLOAT  *x, blasint incx,
	   FLOAT beta,
	   FLOAT  *y, blasint incy){

  FLOAT *buffer;
  blasint lenx, leny;
  int trans, buffer_size;
  blasint info, t;
#ifdef SMP
  int nthreads;
#endif

  int (*gemv[])(BLASLONG, BLASLONG, BLASLONG, FLOAT, FLOAT *, BLASLONG,  FLOAT * , BLASLONG, FLOAT *, BLASLONG, FLOAT *) = {
    GEMV_N, GEMV_T,
  };

  PRINT_DEBUG_CNAME;

  trans = -1;
  info  =  0;

  if (order == CblasColMajor) {
    if (TransA == CblasNoTrans)     trans = 0;
    if (TransA == CblasTrans)       trans = 1;
    if (TransA == CblasConjNoTrans) trans = 0;
    if (TransA == CblasConjTrans)   trans = 1;

    info = -1;

    if (incy == 0)	  info = 11;
    if (incx == 0)	  info = 8;
    if (lda < MAX(1, m))  info = 6;
    if (n < 0)		  info = 3;
    if (m < 0)		  info = 2;
    if (trans < 0)        info = 1;

  }

  if (order == CblasRowMajor) {
    if (TransA == CblasNoTrans)     trans = 1;
    if (TransA == CblasTrans)       trans = 0;
    if (TransA == CblasConjNoTrans) trans = 1;
    if (TransA == CblasConjTrans)   trans = 0;

    info = -1;

    t = n;
    n = m;
    m = t;

    if (incy == 0)	  info = 11;
    if (incx == 0)	  info = 8;
    if (lda < MAX(1, m))  info = 6;
    if (n < 0)		  info = 3;
    if (m < 0)		  info = 2;
    if (trans < 0)        info = 1;

  }

  if (info >= 0) {
    BLASFUNC(xerbla)(ERROR_NAME, &info, sizeof(ERROR_NAME));
    return;
  }

#endif
  if ((m==0) || (n==0)) return;

  lenx = n;
  leny = m;
  if (trans) lenx = m;
  if (trans) leny = n;

  if (beta != ONE) SCAL_K(leny, 0, 0, beta, y, blasabs(incy), NULL, 0, NULL, 0);

  if (alpha == ZERO) return;
	
#if 0
/* this optimization causes stack corruption on x86_64 under OSX, Windows and FreeBSD */	
  if (trans == 0 && incx == 1 && incy == 1 && m*n < 2304 *GEMM_MULTITHREAD_THRESHOLD) {
    GEMV_N(m, n, 0, alpha, a, lda, x, incx, y, incy, NULL);
    return;
  }    
#endif
  IDEBUG_START;

  FUNCTION_PROFILE_START();

  if (incx < 0) x -= (lenx - 1) * incx;
  if (incy < 0) y -= (leny - 1) * incy;

  buffer_size = m + n + 128 / sizeof(FLOAT);
#ifdef WINDOWS_ABI
  buffer_size += 160 / sizeof(FLOAT) ;
#endif
  // for alignment
  buffer_size = (buffer_size + 3) & ~3;
  STACK_ALLOC(buffer_size, FLOAT, buffer);

#ifdef SMP

  if ( 1L * m * n < 2304L * GEMM_MULTITHREAD_THRESHOLD )
    nthreads = 1;
  else
    nthreads = num_cpu_avail(2);

  if (nthreads == 1) {
#endif

    (gemv[(int)trans])(m, n, 0, alpha, a, lda, x, incx, y, incy, buffer);

#ifdef SMP
  } else {

    (gemv_thread[(int)trans])(m, n, alpha, a, lda, x, incx, y, incy, buffer, nthreads);

  }
#endif

  STACK_FREE(buffer);
  FUNCTION_PROFILE_END(1, m * n + m + n,  2 * m * n);

  IDEBUG_END;

  return;

}
