#define PETSCMAT_DLL

/*
    Factorization code for BAIJ format. 
*/
#include "src/mat/impls/baij/seq/baij.h"
#include "src/inline/ilu.h"

/* ------------------------------------------------------------*/
/*
      Version for when blocks are 4 by 4
*/
#undef __FUNCT__  
#define __FUNCT__ "MatLUFactorNumeric_SeqBAIJ_4"
PetscErrorCode MatLUFactorNumeric_SeqBAIJ_4(Mat A,MatFactorInfo *info,Mat *B)
{
  Mat            C = *B;
  Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ *)C->data;
  IS             isrow = b->row,isicol = b->icol;
  PetscErrorCode ierr;
  PetscInt       *r,*ic,i,j,n = a->mbs,*bi = b->i,*bj = b->j;
  PetscInt       *ajtmpold,*ajtmp,nz,row;
  PetscInt       *diag_offset = b->diag,idx,*ai=a->i,*aj=a->j,*pj;
  MatScalar      *pv,*v,*rtmp,*pc,*w,*x;
  MatScalar      p1,p2,p3,p4,m1,m2,m3,m4,m5,m6,m7,m8,m9,x1,x2,x3,x4;
  MatScalar      p5,p6,p7,p8,p9,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15,x16;
  MatScalar      p10,p11,p12,p13,p14,p15,p16,m10,m11,m12;
  MatScalar      m13,m14,m15,m16;
  MatScalar      *ba = b->a,*aa = a->a;
  PetscTruth     pivotinblocks = b->pivotinblocks;
  PetscReal      shift = info->shiftinblocks;

  PetscFunctionBegin;
  ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
  ierr = ISGetIndices(isicol,&ic);CHKERRQ(ierr);
  ierr = PetscMalloc(16*(n+1)*sizeof(MatScalar),&rtmp);CHKERRQ(ierr);

  for (i=0; i<n; i++) {
    nz    = bi[i+1] - bi[i];
    ajtmp = bj + bi[i];
    for  (j=0; j<nz; j++) {
      x = rtmp+16*ajtmp[j]; 
      x[0]  = x[1]  = x[2]  = x[3]  = x[4]  = x[5]  = x[6] = x[7] = x[8] = x[9] = 0.0;
      x[10] = x[11] = x[12] = x[13] = x[14] = x[15] = 0.0;
    }
    /* load in initial (unfactored row) */
    idx      = r[i];
    nz       = ai[idx+1] - ai[idx];
    ajtmpold = aj + ai[idx];
    v        = aa + 16*ai[idx];
    for (j=0; j<nz; j++) {
      x    = rtmp+16*ic[ajtmpold[j]];
      x[0]  = v[0];  x[1]  = v[1];  x[2]  = v[2];  x[3]  = v[3];
      x[4]  = v[4];  x[5]  = v[5];  x[6]  = v[6];  x[7]  = v[7];  x[8]  = v[8];
      x[9]  = v[9];  x[10] = v[10]; x[11] = v[11]; x[12] = v[12]; x[13] = v[13];
      x[14] = v[14]; x[15] = v[15]; 
      v    += 16;
    }
    row = *ajtmp++;
    while (row < i) {
      pc  = rtmp + 16*row;
      p1  = pc[0];  p2  = pc[1];  p3  = pc[2];  p4  = pc[3];
      p5  = pc[4];  p6  = pc[5];  p7  = pc[6];  p8  = pc[7];  p9  = pc[8];
      p10 = pc[9];  p11 = pc[10]; p12 = pc[11]; p13 = pc[12]; p14 = pc[13];
      p15 = pc[14]; p16 = pc[15]; 
      if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0 || p5 != 0.0 ||
          p6 != 0.0 || p7 != 0.0 || p8 != 0.0 || p9 != 0.0 || p10 != 0.0 ||
          p11 != 0.0 || p12 != 0.0 || p13 != 0.0 || p14 != 0.0 || p15 != 0.0
          || p16 != 0.0) {
        pv = ba + 16*diag_offset[row];
        pj = bj + diag_offset[row] + 1;
        x1  = pv[0];  x2  = pv[1];  x3  = pv[2];  x4  = pv[3];
        x5  = pv[4];  x6  = pv[5];  x7  = pv[6];  x8  = pv[7];  x9  = pv[8];
        x10 = pv[9];  x11 = pv[10]; x12 = pv[11]; x13 = pv[12]; x14 = pv[13];
        x15 = pv[14]; x16 = pv[15]; 
        pc[0] = m1 = p1*x1 + p5*x2  + p9*x3  + p13*x4;
        pc[1] = m2 = p2*x1 + p6*x2  + p10*x3 + p14*x4;
        pc[2] = m3 = p3*x1 + p7*x2  + p11*x3 + p15*x4;
        pc[3] = m4 = p4*x1 + p8*x2  + p12*x3 + p16*x4;

        pc[4] = m5 = p1*x5 + p5*x6  + p9*x7  + p13*x8;
        pc[5] = m6 = p2*x5 + p6*x6  + p10*x7 + p14*x8;
        pc[6] = m7 = p3*x5 + p7*x6  + p11*x7 + p15*x8;
        pc[7] = m8 = p4*x5 + p8*x6  + p12*x7 + p16*x8;

        pc[8]  = m9  = p1*x9 + p5*x10  + p9*x11  + p13*x12;
        pc[9]  = m10 = p2*x9 + p6*x10  + p10*x11 + p14*x12;
        pc[10] = m11 = p3*x9 + p7*x10  + p11*x11 + p15*x12;
        pc[11] = m12 = p4*x9 + p8*x10  + p12*x11 + p16*x12;

        pc[12] = m13 = p1*x13 + p5*x14  + p9*x15  + p13*x16;
        pc[13] = m14 = p2*x13 + p6*x14  + p10*x15 + p14*x16;
        pc[14] = m15 = p3*x13 + p7*x14  + p11*x15 + p15*x16;
        pc[15] = m16 = p4*x13 + p8*x14  + p12*x15 + p16*x16;

        nz = bi[row+1] - diag_offset[row] - 1;
        pv += 16;
        for (j=0; j<nz; j++) {
          x1   = pv[0];  x2  = pv[1];   x3 = pv[2];  x4  = pv[3];
          x5   = pv[4];  x6  = pv[5];   x7 = pv[6];  x8  = pv[7]; x9 = pv[8];
          x10  = pv[9];  x11 = pv[10]; x12 = pv[11]; x13 = pv[12];
          x14  = pv[13]; x15 = pv[14]; x16 = pv[15];
          x    = rtmp + 16*pj[j];
          x[0] -= m1*x1 + m5*x2  + m9*x3  + m13*x4;
          x[1] -= m2*x1 + m6*x2  + m10*x3 + m14*x4;
          x[2] -= m3*x1 + m7*x2  + m11*x3 + m15*x4;
          x[3] -= m4*x1 + m8*x2  + m12*x3 + m16*x4;

          x[4] -= m1*x5 + m5*x6  + m9*x7  + m13*x8;
          x[5] -= m2*x5 + m6*x6  + m10*x7 + m14*x8;
          x[6] -= m3*x5 + m7*x6  + m11*x7 + m15*x8;
          x[7] -= m4*x5 + m8*x6  + m12*x7 + m16*x8;

          x[8]  -= m1*x9 + m5*x10 + m9*x11  + m13*x12;
          x[9]  -= m2*x9 + m6*x10 + m10*x11 + m14*x12;
          x[10] -= m3*x9 + m7*x10 + m11*x11 + m15*x12;
          x[11] -= m4*x9 + m8*x10 + m12*x11 + m16*x12;

          x[12] -= m1*x13 + m5*x14  + m9*x15  + m13*x16;
          x[13] -= m2*x13 + m6*x14  + m10*x15 + m14*x16;
          x[14] -= m3*x13 + m7*x14  + m11*x15 + m15*x16;
          x[15] -= m4*x13 + m8*x14  + m12*x15 + m16*x16;

          pv   += 16;
        }
        ierr = PetscLogFlops(128*nz+112);CHKERRQ(ierr);
      }
      row = *ajtmp++;
    }
    /* finished row so stick it into b->a */
    pv = ba + 16*bi[i];
    pj = bj + bi[i];
    nz = bi[i+1] - bi[i];
    for (j=0; j<nz; j++) {
      x      = rtmp+16*pj[j];
      pv[0]  = x[0];  pv[1]  = x[1];  pv[2]  = x[2];  pv[3]  = x[3];
      pv[4]  = x[4];  pv[5]  = x[5];  pv[6]  = x[6];  pv[7]  = x[7]; pv[8] = x[8];
      pv[9]  = x[9];  pv[10] = x[10]; pv[11] = x[11]; pv[12] = x[12];
      pv[13] = x[13]; pv[14] = x[14]; pv[15] = x[15];
      pv   += 16;
    }
    /* invert diagonal block */
    w    = ba + 16*diag_offset[i];
    if (pivotinblocks) {
      ierr = Kernel_A_gets_inverse_A_4(w,shift);CHKERRQ(ierr);
    } else {
      ierr = Kernel_A_gets_inverse_A_4_nopivot(w);CHKERRQ(ierr);
    }
  }

  ierr = PetscFree(rtmp);CHKERRQ(ierr);
  ierr = ISRestoreIndices(isicol,&ic);CHKERRQ(ierr);
  ierr = ISRestoreIndices(isrow,&r);CHKERRQ(ierr);
  C->ops->solve          = MatSolve_SeqBAIJ_4;
  C->ops->solvetranspose = MatSolveTranspose_SeqBAIJ_4;
  C->assembled = PETSC_TRUE;
  ierr = PetscLogFlops(1.3333*64*b->mbs);CHKERRQ(ierr); /* from inverting diagonal blocks */
  PetscFunctionReturn(0);
}