OpenBLAS/lapack/laswp/generic/laswp_k_1.c

/*********************************************************************/
/* Copyright 2009, 2010 The University of Texas at Austin.           */
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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 "common.h"

#ifndef MINUS
#define a2	(a1 + 1)
#else
#define a2	(a1 - 1)
#endif

int CNAME(BLASLONG n, BLASLONG k1, BLASLONG k2, FLOAT dummy1, FLOAT *a, BLASLONG lda,
	 FLOAT *dummy2, BLASLONG dumy3, blasint *ipiv, BLASLONG incx){

  BLASLONG i, j, ip1, ip2, rows;
  blasint *piv;
  FLOAT *a1;
  FLOAT *b1, *b2;
  FLOAT A1, A2, B1, B2;

  a--;
  k1 --;

#ifndef MINUS
 ipiv += k1;
#else
  ipiv -= (k2 - 1) * incx;
#endif

  if (n  <= 0) return 0;

  rows = k2-k1;
  if (rows <=0) return 0;
  if (rows == 1) {
    //Only have 1 row
    ip1 = *ipiv;
    a1 = a + k1 + 1;
    b1 = a + ip1;

    if(a1 == b1) return 0;

    for(j=0; j<n; j++){
	A1 = *a1;
	B1 = *b1;
	*a1 = B1;
	*b1 = A1;

	a1 += lda;
	b1 += lda;
    }
    return 0;
  }

  j = n;
  if (j > 0) {
    do {
      piv = ipiv;

#ifndef MINUS
      a1 = a + k1 + 1;
#else
      a1 = a + k2;
#endif

      ip1 = *piv;
      piv += incx;
      ip2 = *piv;
      piv += incx;

      b1 = a + ip1;
      b2 = a + ip2;

      i = (rows >> 1);

      i--;
      //Main Loop
      while (i > 0) {
#ifdef OPTERON
#ifndef MINUS
	  asm volatile("prefetchw  2 * 128(%0)\n"  : : "r"(a1));
	  asm volatile("prefetchw  2 * 128(%0)\n"  : : "r"(b1));
#else
	  asm volatile("prefetchw -2 * 128(%0)\n"  : : "r"(a1));
	  asm volatile("prefetchw -2 * 128(%0)\n"  : : "r"(b1));
#endif
#endif

#ifdef CORE2
#ifndef MINUS
	  asm volatile("prefetcht1  2 * 128(%0)\n"  : : "r"(a1));
	  asm volatile("prefetcht1  2 * 128(%0)\n"  : : "r"(b1));
	  asm volatile("prefetcht1  2 * 128(%0)\n"  : : "r"(b2));
#else
	  asm volatile("prefetcht1 -2 * 128(%0)\n"  : : "r"(a1));
	  asm volatile("prefetcht1 -2 * 128(%0)\n"  : : "r"(b1));
	  asm volatile("prefetcht1 -2 * 128(%0)\n"  : : "r"(b2));
#endif
#endif
	  A1 = *a1;
	  A2 = *a2;
	  B1 = *b1;
	  B2 = *b2;

	  ip1 = *piv;
	  piv += incx;
	  ip2 = *piv;
	  piv += incx;

	  if (b1 == a1) {
	    if (b2 == a1) {
	      *a1 = A2;
	      *a2 = A1;
	    } else
	      if (b2 != a2) {
		*a2 = B2;
		*b2 = A2;
	      }
	  } else
	    if (b1 == a2) {
	      if (b2 != a1) {
		if (b2 == a2) {
		  *a1 = A2;
		  *a2 = A1;
		} else {
		  *a1 = A2;
		  *a2 = B2;
		  *b2 = A1;
		}
	      }
	    } else {
	      if (b2 == a1) {
		*a1 = A2;
		*a2 = B1;
		*b1 = A1;
	      } else
		if (b2 == a2) {
		  *a1 = B1;
		  *b1 = A1;
		} else
		  if (b2 == b1) {
		    *a1 = B1;
		    *a2 = A1;
		    *b1 = A2;
		  } else {
		    *a1 = B1;
		    *a2 = B2;
		    *b1 = A1;
		    *b2 = A2;
		  }
	    }

	  b1 = a + ip1;
	  b2 = a + ip2;

#ifndef MINUS
	  a1 += 2;
#else
	  a1 -= 2;
#endif
	i --;
      }

      //Loop Ending
      A1 = *a1;
      A2 = *a2;
      B1 = *b1;
      B2 = *b2;
      if (b1 == a1) {
	if (b2 == a1) {
	  *a1 = A2;
	  *a2 = A1;
	} else
	  if (b2 != a2) {
	    *a2 = B2;
	    *b2 = A2;
	  }
      } else
	if (b1 == a2) {
	  if (b2 != a1) {
	    if (b2 == a2) {
	      *a1 = A2;
	      *a2 = A1;
	    } else {
	      *a1 = A2;
	      *a2 = B2;
	      *b2 = A1;
	    }
	  }
	} else {
	  if (b2 == a1) {
	    *a1 = A2;
	    *a2 = B1;
	    *b1 = A1;
	  } else
	    if (b2 == a2) {
	      *a1 = B1;
	      *b1 = A1;
	    } else
	      if (b2 == b1) {
		*a1 = B1;
		*a2 = A1;
		*b1 = A2;
	      } else {
		*a1 = B1;
		*a2 = B2;
		*b1 = A1;
		*b2 = A2;
	      }
	}

#ifndef MINUS
	  a1 += 2;
#else
	  a1 -= 2;
#endif

      //Remain
      i = (rows & 1);

      if (i > 0) {
	ip1 = *piv;
	b1 = a + ip1;

	A1 = *a1;
	B1 = *b1;
	*a1 = B1;
	*b1 = A1;
      }

      a += lda;

      j --;
    } while (j > 0);
  }

  return 0;
}