/*********************************************************************/
/* 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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/*      disclaimer.                                                  */
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/*      provided with the distribution.                              */
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/*    THIS  SOFTWARE IS PROVIDED  BY THE  UNIVERSITY OF  TEXAS AT    */
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/*********************************************************************/

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

#define a2	(a1 + 2)

int CNAME(BLASLONG n, BLASLONG k1, BLASLONG k2, FLOAT *a, BLASLONG lda, blasint *ipiv, FLOAT *buffer){

  BLASLONG i, j, ip1, ip2;
  blasint *piv;
  FLOAT *a1;
  FLOAT *b1, *b2;
  FLOAT A1, A2, A3, A4;
  FLOAT B1, B2, B3, B4;

  a -= 2;
  lda *= 2;
  k1 --;

  ipiv += k1;
  
  if (n  <= 0) return 0;
  
  j = n;
  do {
    piv = ipiv;
    
    a1 = a + (k1 + 1) * 2;
    
    ip1 = *(piv + 0) * 2;
    ip2 = *(piv + 1) * 2;
    piv += 2;
    
    b1 = a + ip1;
    b2 = a + ip2;
    
    i = ((k2 - k1) >> 1);
    
    if (i > 0) {
      do {
	A1 = *(a1 + 0);
	A2 = *(a1 + 1);
	A3 = *(a2 + 0);
	A4 = *(a2 + 1);
	B1 = *(b1 + 0);
	B2 = *(b1 + 1);
	B3 = *(b2 + 0);
	B4 = *(b2 + 1);
	
	ip1 = *(piv + 0) * 2;
	ip2 = *(piv + 1) * 2;
	piv += 2;
	
	if (b1 == a1) {
	    if (b2 == a2) {
	      *(buffer + 0) = A1;
	      *(buffer + 1) = A2;
	      *(buffer + 2) = A3;
	      *(buffer + 3) = A4;
	    } else {
	      *(buffer + 0) = A1;
	      *(buffer + 1) = A2;
	      *(buffer + 2) = B3;
	      *(buffer + 3) = B4;

	      *(b2 + 0) = A3;
	      *(b2 + 1) = A4;
	    }
	} else 
	  if (b1 == a2) {
	      if (b2 == a2) {
		*(buffer + 0) = A3;
		*(buffer + 1) = A4;
		*(buffer + 2) = A1;
		*(buffer + 3) = A2;
	      } else {
		*(buffer + 0) = A3;
		*(buffer + 1) = A4;
		*(buffer + 2) = B3;
		*(buffer + 3) = B4;
		*(b2 + 0) = A1;
		*(b2 + 1) = A2;
	      }
	  } else {
	      if (b2 == a2) {
		*(buffer + 0) = B1;
		*(buffer + 1) = B2;
		*(buffer + 2) = A3;
		*(buffer + 3) = A4;
		*(b1 + 0) = A1;
		*(b1 + 1) = A2;
	      } else 
		if (b2 == b1) {
		  *(buffer + 0) = B1;
		  *(buffer + 1) = B2;
		  *(buffer + 2) = A1;
		  *(buffer + 3) = A2;
		  *(b1 + 0) = A3;
		  *(b1 + 1) = A4;
		} else {
		  *(buffer + 0) = B1;
		  *(buffer + 1) = B2;
		  *(buffer + 2) = B3;
		  *(buffer + 3) = B4;
		  *(b1 + 0) = A1;
		  *(b1 + 1) = A2;
		  *(b2 + 0) = A3;
		  *(b2 + 1) = A4;
		}
	  }
	
	buffer += 4;
	
	b1 = a + ip1;
	b2 = a + ip2;
	
	a1 += 4;
	
	i --;
      } while (i > 0);
    }
    
    i = ((k2 - k1) & 1);
    
    if (i > 0) {
      A1 = *(a1 + 0);
      A2 = *(a1 + 1);
      B1 = *(b1 + 0); 
      B2 = *(b1 + 1);
     
      if (a1 == b1) {
	*(buffer + 0) = A1;
	*(buffer + 1) = A2;
      } else {
	*(buffer + 0) = B1;
	*(buffer + 1) = B2;
	*(b1 + 0) = A1;
	*(b1 + 1) = A2;
      }
      buffer += 2;
    }

    a += lda;
    j --;
  } while (j > 0);

  return 0;
}