OpenBLAS/driver/level2/ztrsv_U.c

/*********************************************************************/
/* Copyright 2009, 2010 The University of Texas at Austin.           */
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/* without modification, are permitted provided that the following   */
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/*      copyright notice, this list of conditions and the following  */
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/*    THIS  SOFTWARE IS PROVIDED  BY THE  UNIVERSITY OF  TEXAS AT    */
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/*********************************************************************/

#include <stdio.h>
#include <ctype.h>
#include "common.h"

const static FLOAT dm1 = -1.;

int CNAME(BLASLONG m, FLOAT *a, BLASLONG lda, FLOAT *b, BLASLONG incb, void *buffer){

  BLASLONG i, is, min_i;
#if (TRANSA == 2) || (TRANSA == 4)
  OPENBLAS_COMPLEX_FLOAT result;
#endif
#ifndef UNIT
  FLOAT ar, ai, br, bi, ratio, den;
#endif
  FLOAT *gemvbuffer = (FLOAT *)buffer;
  FLOAT *B = b;

  if (incb != 1) {
    B = buffer;
    gemvbuffer = (FLOAT *)(((BLASLONG)buffer + m * sizeof(FLOAT) * 2 + 4095) & ~4095);
    COPY_K(m, b, incb, buffer, 1);
  }

  for (is = m; is > 0; is -= DTB_ENTRIES){

    min_i = MIN(is, DTB_ENTRIES);

#if (TRANSA == 2) || (TRANSA == 4)
    if (m - is > 0){
#if TRANSA == 2
      GEMV_T(m - is, min_i, 0, dm1, ZERO,
	      a + (is + (is - min_i)  * lda) * COMPSIZE, lda,
	      B +  is          * COMPSIZE, 1,
	      B + (is - min_i) * COMPSIZE, 1, gemvbuffer);
#else
      GEMV_C(m - is, min_i, 0, dm1, ZERO,
	      a + (is + (is - min_i)  * lda) * COMPSIZE, lda,
	      B +  is            * COMPSIZE, 1,
	      B + (is - min_i)  * COMPSIZE, 1, gemvbuffer);
#endif
    }
#endif

    for (i = 0; i < min_i; i++) {
      FLOAT *AA = a + ((is - i - 1) + (is - i - 1) * lda) * COMPSIZE;
      FLOAT *BB = B + (is - i - 1) * COMPSIZE;

#if (TRANSA == 2) || (TRANSA == 4)
      if (i > 0) {
#if TRANSA == 2
	result = DOTU_K(i, AA + 2, 1, BB + 2, 1);
#else
	result = DOTC_K(i, AA + 2, 1, BB + 2, 1);
#endif

      BB[0] -= CREAL(result);
      BB[1] -= CIMAG(result);
      }
#endif

#ifndef UNIT
      ar = AA[0];
      ai = AA[1];

      if (fabs(ar) >= fabs(ai)){
	ratio = ai / ar;
	den = 1./(ar * ( 1 + ratio * ratio));

	ar =  den;
#if TRANSA < 3
	ai = -ratio * den;
#else
	ai =  ratio * den;
#endif
      } else {
	ratio = ar / ai;
	den = 1./(ai * ( 1 + ratio * ratio));
	ar =  ratio * den;
#if TRANSA < 3
	ai = -den;
#else
	ai =  den;
#endif
    }

      br = BB[0];
      bi = BB[1];

      BB[0] = ar*br - ai*bi;
      BB[1] = ar*bi + ai*br;
#endif

#if (TRANSA == 1) || (TRANSA == 3)
      if (i < min_i - 1) {
#if TRANSA == 1
	AXPYU_K (min_i - i - 1, 0, 0, - BB[0], -BB[1],
		 AA - (min_i - i - 1) * COMPSIZE, 1, BB - (min_i - i - 1) * COMPSIZE, 1, NULL, 0);
#else
	AXPYC_K(min_i - i - 1, 0, 0, - BB[0], -BB[1],
		 AA - (min_i - i - 1) * COMPSIZE, 1, BB - (min_i - i - 1) * COMPSIZE, 1, NULL, 0);
#endif
      }
#endif
    }

#if (TRANSA == 1) || (TRANSA == 3)
    if (is - min_i > 0){
#if   TRANSA == 1
      GEMV_N(is - min_i, min_i, 0, dm1, ZERO,
	      a +  (is - min_i) * lda * COMPSIZE, lda,
	      B +  (is - min_i)       * COMPSIZE, 1,
	      B,                                  1, gemvbuffer);
#else
      GEMV_R(is - min_i, min_i, 0, dm1, ZERO,
	      a +  (is - min_i) * lda * COMPSIZE, lda,
	      B +  (is - min_i)       * COMPSIZE, 1,
	      B,                                  1, gemvbuffer);
#endif
    }
#endif
  }

  if (incb != 1) {
    COPY_K(m, buffer, 1, b, incb);
  }

  return 0;
}