/*********************************************************************/
/* 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)
#define a4	(a3 + 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, *a3;
  FLOAT *b1, *b2, *b3, *b4;
  FLOAT A1, A2, A3, A4;
  FLOAT A5, A6, A7, A8;
  FLOAT B1, B2, B3, B4;
  FLOAT B5, B6, B7, B8;

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

 ipiv += k1;

  if (n  <= 0) return 0;
      
  j = (n >> 1);
  if (j > 0) {
    do {
      piv = ipiv;
      
      a1 = a + (k1 + 1) * 2;
      a3 = a1 + lda;
      
      ip1 = *(piv + 0) * 2;
      ip2 = *(piv + 1) * 2;
      piv += 2;
      
      b1 = a + ip1;
      b2 = a + ip2;
      
      b3 = b1 + lda;
      b4 = b2 + lda;
      
      i = ((k2 - k1) >> 1);
      
      if (i > 0) {
	do {
	  A1 = *(a1 + 0);
	  A2 = *(a1 + 1);
	  A3 = *(a2 + 0);
	  A4 = *(a2 + 1);
	  A5 = *(a3 + 0);
	  A6 = *(a3 + 1);
	  A7 = *(a4 + 0);
	  A8 = *(a4 + 1);

	  B1 = *(b1 + 0);
	  B2 = *(b1 + 1);
	  B3 = *(b2 + 0);
	  B4 = *(b2 + 1);
	  B5 = *(b3 + 0);
	  B6 = *(b3 + 1);
	  B7 = *(b4 + 0);
	  B8 = *(b4 + 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) = A5;
	      *(buffer + 3) = A6;
	      *(buffer + 4) = A3;
	      *(buffer + 5) = A4;
	      *(buffer + 6) = A7;
	      *(buffer + 7) = A8;
	    } else {
	      *(buffer + 0) = A1;
	      *(buffer + 1) = A2;
	      *(buffer + 2) = A5;
	      *(buffer + 3) = A6;
	      *(buffer + 4) = B3;
	      *(buffer + 5) = B4;
	      *(buffer + 6) = B7;
	      *(buffer + 7) = B8;
	      
	      *(b2 + 0) = A3;
	      *(b2 + 1) = A4;
	      *(b4 + 0) = A7;
	      *(b4 + 1) = A8;
	    }
	} else 
	  if (b1 == a2) {
	    if (b2 == a2) {
	      *(buffer + 0) = A3;
	      *(buffer + 1) = A4;
	      *(buffer + 2) = A7;
	      *(buffer + 3) = A8;
	      *(buffer + 4) = A1;
	      *(buffer + 5) = A2;
	      *(buffer + 6) = A5;
	      *(buffer + 7) = A6;
	    } else {
	      *(buffer + 0) = A3;
	      *(buffer + 1) = A4;
	      *(buffer + 2) = A7;
	      *(buffer + 3) = A8;
	      *(buffer + 4) = B3;
	      *(buffer + 5) = B4;
	      *(buffer + 6) = B7;
	      *(buffer + 7) = B8;

	      *(b2 + 0) = A1;
	      *(b2 + 1) = A2;
	      *(b4 + 0) = A5;
	      *(b4 + 1) = A6;
	    }
	  } else {
	    if (b2 == a2) {
	      *(buffer + 0) = B1;
	      *(buffer + 1) = B2;
	      *(buffer + 2) = B5;
	      *(buffer + 3) = B6;
	      *(buffer + 4) = A3;
	      *(buffer + 5) = A4;
	      *(buffer + 6) = A7;
	      *(buffer + 7) = A8;

	      *(b1 + 0) = A1;
	      *(b1 + 1) = A2;
	      *(b3 + 0) = A5;
	      *(b3 + 1) = A6;
	    } else 
	      if (b2 == b1) {
		*(buffer + 0) = B1;
		*(buffer + 1) = B2;
		*(buffer + 2) = B5;
		*(buffer + 3) = B6;
		*(buffer + 4) = A1;
		*(buffer + 5) = A2;
		*(buffer + 6) = A5;
		*(buffer + 7) = A6;

		*(b1 + 0) = A3;
		*(b1 + 1) = A4;
		*(b3 + 0) = A7;
		*(b3 + 1) = A8;
	      } else {
		*(buffer + 0) = B1;
		*(buffer + 1) = B2;
		*(buffer + 2) = B5;
		*(buffer + 3) = B6;
		*(buffer + 4) = B3;
		*(buffer + 5) = B4;
		*(buffer + 6) = B7;
		*(buffer + 7) = B8;
		*(b1 + 0) = A1;
		*(b1 + 1) = A2;
		*(b2 + 0) = A3;
		*(b2 + 1) = A4;
		*(b3 + 0) = A5;
		*(b3 + 1) = A6;
		*(b4 + 0) = A7;
		*(b4 + 1) = A8;
	      }
	  }
	  
	  buffer += 8;
	  
	  b1 = a + ip1;
	  b2 = a + ip2;
	  
	  b3 = b1 + lda;
	  b4 = b2 + lda;
	  
	  a1 += 4;
	  a3 += 4;
	  
	  i --;
	} while (i > 0);
      }
      
      i = ((k2 - k1) & 1);
      
      if (i > 0) {
	A1 = *(a1 + 0);
	A2 = *(a1 + 1);
	B1 = *(b1 + 0);
	B2 = *(b1 + 1);
	A3 = *(a3 + 0);
	A4 = *(a3 + 1);
	B3 = *(b3 + 0);
	B4 = *(b3 + 1);
	
	if (a1 == b1) {
	  *(buffer + 0) = A1;
	  *(buffer + 1) = A2;
	  *(buffer + 2) = A3;
	  *(buffer + 3) = A4;

	} else {
	  *(buffer + 0) = B1;
	  *(buffer + 1) = B2;
	  *(buffer + 2) = B3;
	  *(buffer + 3) = B4;
	  *(b1 + 0) = A1;
	  *(b1 + 1) = A2;
	  *(b3 + 0) = A3;
	  *(b3 + 1) = A4;
	}
	buffer += 4;
      }
      
      a += 2 * lda;
      j --;
    } while (j > 0);
  }
  
  if (n & 1) {
    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;
    }
  }

  return 0;
} 

