gcc/libgfortran/generated/matmul_i4.c

/* Implementation of the MATMUL intrinsic
Copyright (C) 2002-2017 Free Software Foundation, Inc.
Contributed by Paul Brook <paul@nowt.org>

This file is part of the GNU Fortran runtime library (libgfortran).

Libgfortran is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.

Libgfortran is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  */

#include "liblfortran.h"
#include <string.h>
#include <assert.h>


#if defined (HAVE_GFC_INTEGER_4)

/* Prototype for the BLAS ?gemm subroutine, a pointer to which can be
passed to us by the front-end, in which case we call it for large
matrices.  */

typedef void (*blas_call)(const char *, const char *, const int *, const int *,
                          const int *, const GFC_INTEGER_4 *, const GFC_INTEGER_4 *,
                          const int *, const GFC_INTEGER_4 *, const int *,
                          const GFC_INTEGER_4 *, GFC_INTEGER_4 *, const int *,
                          int, int);

/* The order of loops is different in the case of plain matrix
multiplication C=MATMUL(A,B), and in the frequent special case where
the argument A is the temporary result of a TRANSPOSE intrinsic:
C=MATMUL(TRANSPOSE(A),B).  Transposed temporaries are detected by
looking at their strides.

The equivalent Fortran pseudo-code is:

DIMENSION A(M,COUNT), B(COUNT,N), C(M,N)
IF (.NOT.IS_TRANSPOSED(A)) THEN
C = 0
DO J=1,N
DO K=1,COUNT
DO I=1,M
C(I,J) = C(I,J)+A(I,K)*B(K,J)
ELSE
DO J=1,N
DO I=1,M
S = 0
DO K=1,COUNT
S = S+A(I,K)*B(K,J)
C(I,J) = S
ENDIF
*/

/* If try_blas is set to a nonzero value, then the matmul function will
see if there is a way to perform the matrix multiplication by a call
to the BLAS gemm function.  */

extern void matmul_i4 (gfc_array_i4 * const restrict retarray, 
                       gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
                       int blas_limit, blas_call gemm);
export_proto(matmul_i4);

/* Put exhaustive list of possible architectures here here, ORed together.  */

#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_AVX512F)

#ifdef HAVE_AVX
static void
    matmul_i4_avx (gfc_array_i4 * const restrict retarray, 
    gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
    int blas_limit, blas_call gemm) __attribute__((__target__("avx")));
static void
    matmul_i4_avx (gfc_array_i4 * const restrict retarray, 
    gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
    int blas_limit, blas_call gemm)
{
    const GFC_INTEGER_4 * restrict abase;
    const GFC_INTEGER_4 * restrict bbase;
    GFC_INTEGER_4 * restrict dest;

    index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
    index_type x, y, n, count, xcount, ycount;

    assert (GFC_DESCRIPTOR_RANK (a) == 2
        || GFC_DESCRIPTOR_RANK (b) == 2);

    /* C[xcount,ycount] = A[xcount, count] * B[count,ycount]

    Either A or B (but not both) can be rank 1:

    o One-dimensional argument A is implicitly treated as a row matrix
    dimensioned [1,count], so xcount=1.

    o One-dimensional argument B is implicitly treated as a column matrix
    dimensioned [count, 1], so ycount=1.
    */

    if (retarray->base_addr == NULL)
    {
        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
        }
        else
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);

            GFC_DIMENSION_SET(retarray->dim[1], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1,
                GFC_DESCRIPTOR_EXTENT(retarray,0));
        }

        retarray->base_addr
            = xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_4));
        retarray->offset = 0;
    }
    else if (unlikely (compile_options.bounds_check))
    {
        index_type ret_extent, arg_extent;

        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 1: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);

            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 2: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);	}
    }


    if (GFC_DESCRIPTOR_RANK (retarray) == 1)
    {
        /* One-dimensional result may be addressed in the code below
        either as a row or a column matrix. We want both cases to
        work. */
        rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
    }
    else
    {
        rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
        rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
    }


    if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        /* Treat it as a a row matrix A[1,count]. */
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = 1;

        xcount = 1;
        count = GFC_DESCRIPTOR_EXTENT(a,0);
    }
    else
    {
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = GFC_DESCRIPTOR_STRIDE(a,1);

        count = GFC_DESCRIPTOR_EXTENT(a,1);
        xcount = GFC_DESCRIPTOR_EXTENT(a,0);
    }

    if (count != GFC_DESCRIPTOR_EXTENT(b,0))
    {
        if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
            runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
    }

    if (GFC_DESCRIPTOR_RANK (b) == 1)
    {
        /* Treat it as a column matrix B[count,1] */
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);

        /* bystride should never be used for 1-dimensional b.
        in case it is we want it to cause a segfault, rather than
        an incorrect result. */
        bystride = 0xDEADBEEF;
        ycount = 1;
    }
    else
    {
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
        bystride = GFC_DESCRIPTOR_STRIDE(b,1);
        ycount = GFC_DESCRIPTOR_EXTENT(b,1);
    }

    abase = a->base_addr;
    bbase = b->base_addr;
    dest = retarray->base_addr;

    /* Now that everything is set up, we perform the multiplication
    itself.  */

#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
#define min(a,b) ((a) <= (b) ? (a) : (b))
#define max(a,b) ((a) >= (b) ? (a) : (b))

    if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
        && (bxstride == 1 || bystride == 1)
        && (((float) xcount) * ((float) ycount) * ((float) count)
          > POW3(blas_limit)))
    {
        const int m = xcount, n = ycount, k = count, ldc = rystride;
        const GFC_INTEGER_4 one = 1, zero = 0;
        const int lda = (axstride == 1) ? aystride : axstride,
            ldb = (bxstride == 1) ? bystride : bxstride;

        if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
        {
            assert (gemm != NULL);
            gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
                &n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
                &ldc, 1, 1);
            return;
        }
    }

    if (rxstride == 1 && axstride == 1 && bxstride == 1)
    {
        /* This block of code implements a tuned matmul, derived from
        Superscalar GEMM-based level 3 BLAS,  Beta version 0.1

        Bo Kagstrom and Per Ling
        Department of Computing Science
        Umea University
        S-901 87 Umea, Sweden

        from netlib.org, translated to C, and modified for matmul.m4.  */

        const GFC_INTEGER_4 *a, *b;
        GFC_INTEGER_4 *c;
        const index_type m = xcount, n = ycount, k = count;

        /* System generated locals */
        index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
            i1, i2, i3, i4, i5, i6;

        /* Local variables */
        GFC_INTEGER_4 t1[65536], /* was [256][256] */
            f11, f12, f21, f22, f31, f32, f41, f42,
            f13, f14, f23, f24, f33, f34, f43, f44;
        index_type i, j, l, ii, jj, ll;
        index_type isec, jsec, lsec, uisec, ujsec, ulsec;

        a = abase;
        b = bbase;
        c = retarray->base_addr;

        /* Parameter adjustments */
        c_dim1 = rystride;
        c_offset = 1 + c_dim1;
        c -= c_offset;
        a_dim1 = aystride;
        a_offset = 1 + a_dim1;
        a -= a_offset;
        b_dim1 = bystride;
        b_offset = 1 + b_dim1;
        b -= b_offset;

        /* Empty c first.  */
        for (j=1; j<=n; j++)
            for (i=1; i<=m; i++)
                c[i + j * c_dim1] = (GFC_INTEGER_4)0;

        /* Early exit if possible */
        if (m == 0 || n == 0 || k == 0)
            return;

        /* Start turning the crank. */
        i1 = n;
        for (jj = 1; jj <= i1; jj += 512)
        {
            /* Computing MIN */
            i2 = 512;
            i3 = n - jj + 1;
            jsec = min(i2,i3);
            ujsec = jsec - jsec % 4;
            i2 = k;
            for (ll = 1; ll <= i2; ll += 256)
            {
                /* Computing MIN */
                i3 = 256;
                i4 = k - ll + 1;
                lsec = min(i3,i4);
                ulsec = lsec - lsec % 2;

                i3 = m;
                for (ii = 1; ii <= i3; ii += 256)
                {
                    /* Computing MIN */
                    i4 = 256;
                    i5 = m - ii + 1;
                    isec = min(i4,i5);
                    uisec = isec - isec % 2;
                    i4 = ll + ulsec - 1;
                    for (l = ll; l <= i4; l += 2)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 2)
                        {
                            t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
                                a[i + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
                                a[i + (l + 1) * a_dim1];
                            t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + (l + 1) * a_dim1];
                        }
                        if (uisec < isec)
                        {
                            t1[l - ll + 1 + (isec << 8) - 257] =
                                a[ii + isec - 1 + l * a_dim1];
                            t1[l - ll + 2 + (isec << 8) - 257] =
                                a[ii + isec - 1 + (l + 1) * a_dim1];
                        }
                    }
                    if (ulsec < lsec)
                    {
                        i4 = ii + isec - 1;
                        for (i = ii; i<= i4; ++i)
                        {
                            t1[lsec + ((i - ii + 1) << 8) - 257] =
                                a[i + (ll + lsec - 1) * a_dim1];
                        }
                    }

                    uisec = isec - isec % 4;
                    i4 = jj + ujsec - 1;
                    for (j = jj; j <= i4; j += 4)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 4)
                        {
                            f11 = c[i + j * c_dim1];
                            f21 = c[i + 1 + j * c_dim1];
                            f12 = c[i + (j + 1) * c_dim1];
                            f22 = c[i + 1 + (j + 1) * c_dim1];
                            f13 = c[i + (j + 2) * c_dim1];
                            f23 = c[i + 1 + (j + 2) * c_dim1];
                            f14 = c[i + (j + 3) * c_dim1];
                            f24 = c[i + 1 + (j + 3) * c_dim1];
                            f31 = c[i + 2 + j * c_dim1];
                            f41 = c[i + 3 + j * c_dim1];
                            f32 = c[i + 2 + (j + 1) * c_dim1];
                            f42 = c[i + 3 + (j + 1) * c_dim1];
                            f33 = c[i + 2 + (j + 2) * c_dim1];
                            f43 = c[i + 3 + (j + 2) * c_dim1];
                            f34 = c[i + 2 + (j + 3) * c_dim1];
                            f44 = c[i + 3 + (j + 3) * c_dim1];
                            i6 = ll + lsec - 1;
                            for (l = ll; l <= i6; ++l)
                            {
                                f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + j * b_dim1];
                                f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + j * b_dim1];
                                f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + j * b_dim1];
                                f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + j * b_dim1];
                                f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                            }
                            c[i + j * c_dim1] = f11;
                            c[i + 1 + j * c_dim1] = f21;
                            c[i + (j + 1) * c_dim1] = f12;
                            c[i + 1 + (j + 1) * c_dim1] = f22;
                            c[i + (j + 2) * c_dim1] = f13;
                            c[i + 1 + (j + 2) * c_dim1] = f23;
                            c[i + (j + 3) * c_dim1] = f14;
                            c[i + 1 + (j + 3) * c_dim1] = f24;
                            c[i + 2 + j * c_dim1] = f31;
                            c[i + 3 + j * c_dim1] = f41;
                            c[i + 2 + (j + 1) * c_dim1] = f32;
                            c[i + 3 + (j + 1) * c_dim1] = f42;
                            c[i + 2 + (j + 2) * c_dim1] = f33;
                            c[i + 3 + (j + 2) * c_dim1] = f43;
                            c[i + 2 + (j + 3) * c_dim1] = f34;
                            c[i + 3 + (j + 3) * c_dim1] = f44;
                        }
                        if (uisec < isec)
                        {
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                f12 = c[i + (j + 1) * c_dim1];
                                f13 = c[i + (j + 2) * c_dim1];
                                f14 = c[i + (j + 3) * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 1) * b_dim1];
                                    f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 2) * b_dim1];
                                    f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 3) * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + (j + 1) * c_dim1] = f12;
                                c[i + (j + 2) * c_dim1] = f13;
                                c[i + (j + 3) * c_dim1] = f14;
                            }
                        }
                    }
                    if (ujsec < jsec)
                    {
                        i4 = jj + jsec - 1;
                        for (j = jj + ujsec; j <= i4; ++j)
                        {
                            i5 = ii + uisec - 1;
                            for (i = ii; i <= i5; i += 4)
                            {
                                f11 = c[i + j * c_dim1];
                                f21 = c[i + 1 + j * c_dim1];
                                f31 = c[i + 2 + j * c_dim1];
                                f41 = c[i + 3 + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + 1 + j * c_dim1] = f21;
                                c[i + 2 + j * c_dim1] = f31;
                                c[i + 3 + j * c_dim1] = f41;
                            }
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                            }
                        }
                    }
                }
            }
        }
        return;
    }
    else if (rxstride == 1 && aystride == 1 && bxstride == 1)
    {
        if (GFC_DESCRIPTOR_RANK (a) != 1)
        {
            const GFC_INTEGER_4 *restrict abase_x;
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 *restrict dest_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                dest_y = &dest[y*rystride];
                for (x = 0; x < xcount; x++)
                {
                    abase_x = &abase[x*axstride];
                    s = (GFC_INTEGER_4) 0;
                    for (n = 0; n < count; n++)
                        s += abase_x[n] * bbase_y[n];
                    dest_y[x] = s;
                }
            }
        }
        else
        {
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase[n*axstride] * bbase_y[n];
                dest[y*rystride] = s;
            }
        }
    }
    // else if (axstride < aystride)
    //   {
    //     for (y = 0; y < ycount; y++)
    //for (x = 0; x < xcount; x++)
    //  dest[x*rxstride + y*rystride] = (GFC_INTEGER_4)0;

    //     for (y = 0; y < ycount; y++)
    //for (n = 0; n < count; n++)
    //  for (x = 0; x < xcount; x++)
    //    /* dest[x,y] += a[x,n] * b[n,y] */
    //    dest[x*rxstride + y*rystride] +=
    //				abase[x*axstride + n*aystride] *
    //				bbase[n*bxstride + y*bystride];
    //   }
    else if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            s = (GFC_INTEGER_4) 0;
            for (n = 0; n < count; n++)
                s += abase[n*axstride] * bbase_y[n*bxstride];
            dest[y*rxstride] = s;
        }
    }
    else
    {
        const GFC_INTEGER_4 *restrict abase_x;
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 *restrict dest_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            dest_y = &dest[y*rystride];
            for (x = 0; x < xcount; x++)
            {
                abase_x = &abase[x*axstride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase_x[n*aystride] * bbase_y[n*bxstride];
                dest_y[x*rxstride] = s;
            }
        }
    }
}
#undef POW3
#undef min
#undef max

#endif /* HAVE_AVX */

#ifdef HAVE_AVX2
static void
    matmul_i4_avx2 (gfc_array_i4 * const restrict retarray, 
    gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
    int blas_limit, blas_call gemm) __attribute__((__target__("avx2,fma")));
static void
    matmul_i4_avx2 (gfc_array_i4 * const restrict retarray, 
    gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
    int blas_limit, blas_call gemm)
{
    const GFC_INTEGER_4 * restrict abase;
    const GFC_INTEGER_4 * restrict bbase;
    GFC_INTEGER_4 * restrict dest;

    index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
    index_type x, y, n, count, xcount, ycount;

    assert (GFC_DESCRIPTOR_RANK (a) == 2
        || GFC_DESCRIPTOR_RANK (b) == 2);

    /* C[xcount,ycount] = A[xcount, count] * B[count,ycount]

    Either A or B (but not both) can be rank 1:

    o One-dimensional argument A is implicitly treated as a row matrix
    dimensioned [1,count], so xcount=1.

    o One-dimensional argument B is implicitly treated as a column matrix
    dimensioned [count, 1], so ycount=1.
    */

    if (retarray->base_addr == NULL)
    {
        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
        }
        else
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);

            GFC_DIMENSION_SET(retarray->dim[1], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1,
                GFC_DESCRIPTOR_EXTENT(retarray,0));
        }

        retarray->base_addr
            = xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_4));
        retarray->offset = 0;
    }
    else if (unlikely (compile_options.bounds_check))
    {
        index_type ret_extent, arg_extent;

        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 1: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);

            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 2: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
    }


    if (GFC_DESCRIPTOR_RANK (retarray) == 1)
    {
        /* One-dimensional result may be addressed in the code below
        either as a row or a column matrix. We want both cases to
        work. */
        rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
    }
    else
    {
        rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
        rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
    }


    if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        /* Treat it as a a row matrix A[1,count]. */
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = 1;

        xcount = 1;
        count = GFC_DESCRIPTOR_EXTENT(a,0);
    }
    else
    {
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = GFC_DESCRIPTOR_STRIDE(a,1);

        count = GFC_DESCRIPTOR_EXTENT(a,1);
        xcount = GFC_DESCRIPTOR_EXTENT(a,0);
    }

    if (count != GFC_DESCRIPTOR_EXTENT(b,0))
    {
        if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
            runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
    }

    if (GFC_DESCRIPTOR_RANK (b) == 1)
    {
        /* Treat it as a column matrix B[count,1] */
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);

        /* bystride should never be used for 1-dimensional b.
        in case it is we want it to cause a segfault, rather than
        an incorrect result. */
        bystride = 0xDEADBEEF;
        ycount = 1;
    }
    else
    {
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
        bystride = GFC_DESCRIPTOR_STRIDE(b,1);
        ycount = GFC_DESCRIPTOR_EXTENT(b,1);
    }

    abase = a->base_addr;
    bbase = b->base_addr;
    dest = retarray->base_addr;

    /* Now that everything is set up, we perform the multiplication
    itself.  */

#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
#define min(a,b) ((a) <= (b) ? (a) : (b))
#define max(a,b) ((a) >= (b) ? (a) : (b))

    if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
        && (bxstride == 1 || bystride == 1)
        && (((float) xcount) * ((float) ycount) * ((float) count)
        > POW3(blas_limit)))
    {
        const int m = xcount, n = ycount, k = count, ldc = rystride;
        const GFC_INTEGER_4 one = 1, zero = 0;
        const int lda = (axstride == 1) ? aystride : axstride,
            ldb = (bxstride == 1) ? bystride : bxstride;

        if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
        {
            assert (gemm != NULL);
            gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
                &n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
                &ldc, 1, 1);
            return;
        }
    }

    if (rxstride == 1 && axstride == 1 && bxstride == 1)
    {
        /* This block of code implements a tuned matmul, derived from
        Superscalar GEMM-based level 3 BLAS,  Beta version 0.1

        Bo Kagstrom and Per Ling
        Department of Computing Science
        Umea University
        S-901 87 Umea, Sweden

        from netlib.org, translated to C, and modified for matmul.m4.  */

        const GFC_INTEGER_4 *a, *b;
        GFC_INTEGER_4 *c;
        const index_type m = xcount, n = ycount, k = count;

        /* System generated locals */
        index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
            i1, i2, i3, i4, i5, i6;

        /* Local variables */
        GFC_INTEGER_4 t1[65536], /* was [256][256] */
            f11, f12, f21, f22, f31, f32, f41, f42,
            f13, f14, f23, f24, f33, f34, f43, f44;
        index_type i, j, l, ii, jj, ll;
        index_type isec, jsec, lsec, uisec, ujsec, ulsec;

        a = abase;
        b = bbase;
        c = retarray->base_addr;

        /* Parameter adjustments */
        c_dim1 = rystride;
        c_offset = 1 + c_dim1;
        c -= c_offset;
        a_dim1 = aystride;
        a_offset = 1 + a_dim1;
        a -= a_offset;
        b_dim1 = bystride;
        b_offset = 1 + b_dim1;
        b -= b_offset;

        /* Empty c first.  */
        for (j=1; j<=n; j++)
            for (i=1; i<=m; i++)
                c[i + j * c_dim1] = (GFC_INTEGER_4)0;

        /* Early exit if possible */
        if (m == 0 || n == 0 || k == 0)
            return;

        /* Start turning the crank. */
        i1 = n;
        for (jj = 1; jj <= i1; jj += 512)
        {
            /* Computing MIN */
            i2 = 512;
            i3 = n - jj + 1;
            jsec = min(i2,i3);
            ujsec = jsec - jsec % 4;
            i2 = k;
            for (ll = 1; ll <= i2; ll += 256)
            {
                /* Computing MIN */
                i3 = 256;
                i4 = k - ll + 1;
                lsec = min(i3,i4);
                ulsec = lsec - lsec % 2;

                i3 = m;
                for (ii = 1; ii <= i3; ii += 256)
                {
                    /* Computing MIN */
                    i4 = 256;
                    i5 = m - ii + 1;
                    isec = min(i4,i5);
                    uisec = isec - isec % 2;
                    i4 = ll + ulsec - 1;
                    for (l = ll; l <= i4; l += 2)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 2)
                        {
                            t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
                                a[i + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
                                a[i + (l + 1) * a_dim1];
                            t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + (l + 1) * a_dim1];
                        }
                        if (uisec < isec)
                        {
                            t1[l - ll + 1 + (isec << 8) - 257] =
                                a[ii + isec - 1 + l * a_dim1];
                            t1[l - ll + 2 + (isec << 8) - 257] =
                                a[ii + isec - 1 + (l + 1) * a_dim1];
                        }
                    }
                    if (ulsec < lsec)
                    {
                        i4 = ii + isec - 1;
                        for (i = ii; i<= i4; ++i)
                        {
                            t1[lsec + ((i - ii + 1) << 8) - 257] =
                                a[i + (ll + lsec - 1) * a_dim1];
                        }
                    }

                    uisec = isec - isec % 4;
                    i4 = jj + ujsec - 1;
                    for (j = jj; j <= i4; j += 4)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 4)
                        {
                            f11 = c[i + j * c_dim1];
                            f21 = c[i + 1 + j * c_dim1];
                            f12 = c[i + (j + 1) * c_dim1];
                            f22 = c[i + 1 + (j + 1) * c_dim1];
                            f13 = c[i + (j + 2) * c_dim1];
                            f23 = c[i + 1 + (j + 2) * c_dim1];
                            f14 = c[i + (j + 3) * c_dim1];
                            f24 = c[i + 1 + (j + 3) * c_dim1];
                            f31 = c[i + 2 + j * c_dim1];
                            f41 = c[i + 3 + j * c_dim1];
                            f32 = c[i + 2 + (j + 1) * c_dim1];
                            f42 = c[i + 3 + (j + 1) * c_dim1];
                            f33 = c[i + 2 + (j + 2) * c_dim1];
                            f43 = c[i + 3 + (j + 2) * c_dim1];
                            f34 = c[i + 2 + (j + 3) * c_dim1];
                            f44 = c[i + 3 + (j + 3) * c_dim1];
                            i6 = ll + lsec - 1;
                            for (l = ll; l <= i6; ++l)
                            {
                                f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + j * b_dim1];
                                f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + j * b_dim1];
                                f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + j * b_dim1];
                                f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + j * b_dim1];
                                f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                            }
                            c[i + j * c_dim1] = f11;
                            c[i + 1 + j * c_dim1] = f21;
                            c[i + (j + 1) * c_dim1] = f12;
                            c[i + 1 + (j + 1) * c_dim1] = f22;
                            c[i + (j + 2) * c_dim1] = f13;
                            c[i + 1 + (j + 2) * c_dim1] = f23;
                            c[i + (j + 3) * c_dim1] = f14;
                            c[i + 1 + (j + 3) * c_dim1] = f24;
                            c[i + 2 + j * c_dim1] = f31;
                            c[i + 3 + j * c_dim1] = f41;
                            c[i + 2 + (j + 1) * c_dim1] = f32;
                            c[i + 3 + (j + 1) * c_dim1] = f42;
                            c[i + 2 + (j + 2) * c_dim1] = f33;
                            c[i + 3 + (j + 2) * c_dim1] = f43;
                            c[i + 2 + (j + 3) * c_dim1] = f34;
                            c[i + 3 + (j + 3) * c_dim1] = f44;
                        }
                        if (uisec < isec)
                        {
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                f12 = c[i + (j + 1) * c_dim1];
                                f13 = c[i + (j + 2) * c_dim1];
                                f14 = c[i + (j + 3) * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 1) * b_dim1];
                                    f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 2) * b_dim1];
                                    f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 3) * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + (j + 1) * c_dim1] = f12;
                                c[i + (j + 2) * c_dim1] = f13;
                                c[i + (j + 3) * c_dim1] = f14;
                            }
                        }
                    }
                    if (ujsec < jsec)
                    {
                        i4 = jj + jsec - 1;
                        for (j = jj + ujsec; j <= i4; ++j)
                        {
                            i5 = ii + uisec - 1;
                            for (i = ii; i <= i5; i += 4)
                            {
                                f11 = c[i + j * c_dim1];
                                f21 = c[i + 1 + j * c_dim1];
                                f31 = c[i + 2 + j * c_dim1];
                                f41 = c[i + 3 + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + 1 + j * c_dim1] = f21;
                                c[i + 2 + j * c_dim1] = f31;
                                c[i + 3 + j * c_dim1] = f41;
                            }
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                            }
                        }
                    }
                }
            }
        }
        return;
    }
    else if (rxstride == 1 && aystride == 1 && bxstride == 1)
    {
        if (GFC_DESCRIPTOR_RANK (a) != 1)
        {
            const GFC_INTEGER_4 *restrict abase_x;
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 *restrict dest_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                dest_y = &dest[y*rystride];
                for (x = 0; x < xcount; x++)
                {
                    abase_x = &abase[x*axstride];
                    s = (GFC_INTEGER_4) 0;
                    for (n = 0; n < count; n++)
                        s += abase_x[n] * bbase_y[n];
                    dest_y[x] = s;
                }
            }
        }
        else
        {
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase[n*axstride] * bbase_y[n];
                dest[y*rystride] = s;
            }
        }
    }
    // else if (axstride < aystride)
    //   {
    //     for (y = 0; y < ycount; y++)
    //for (x = 0; x < xcount; x++)
    //  dest[x*rxstride + y*rystride] = (GFC_INTEGER_4)0;

    //     for (y = 0; y < ycount; y++)
    //for (n = 0; n < count; n++)
    //  for (x = 0; x < xcount; x++)
    //    /* dest[x,y] += a[x,n] * b[n,y] */
    //    dest[x*rxstride + y*rystride] +=
    //				abase[x*axstride + n*aystride] *
    //				bbase[n*bxstride + y*bystride];
    //   }
    else if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            s = (GFC_INTEGER_4) 0;
            for (n = 0; n < count; n++)
                s += abase[n*axstride] * bbase_y[n*bxstride];
            dest[y*rxstride] = s;
        }
    }
    else
    {
        const GFC_INTEGER_4 *restrict abase_x;
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 *restrict dest_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            dest_y = &dest[y*rystride];
            for (x = 0; x < xcount; x++)
            {
                abase_x = &abase[x*axstride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase_x[n*aystride] * bbase_y[n*bxstride];
                dest_y[x*rxstride] = s;
            }
        }
    }
}
#undef POW3
#undef min
#undef max

#endif /* HAVE_AVX2 */

#ifdef HAVE_AVX512F
static void
    matmul_i4_avx512f (gfc_array_i4 * const restrict retarray, 
    gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
    int blas_limit, blas_call gemm) __attribute__((__target__("avx512f")));
static void
    matmul_i4_avx512f (gfc_array_i4 * const restrict retarray, 
    gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
    int blas_limit, blas_call gemm)
{
    const GFC_INTEGER_4 * restrict abase;
    const GFC_INTEGER_4 * restrict bbase;
    GFC_INTEGER_4 * restrict dest;

    index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
    index_type x, y, n, count, xcount, ycount;

    assert (GFC_DESCRIPTOR_RANK (a) == 2
        || GFC_DESCRIPTOR_RANK (b) == 2);

    /* C[xcount,ycount] = A[xcount, count] * B[count,ycount]

    Either A or B (but not both) can be rank 1:

    o One-dimensional argument A is implicitly treated as a row matrix
    dimensioned [1,count], so xcount=1.

    o One-dimensional argument B is implicitly treated as a column matrix
    dimensioned [count, 1], so ycount=1.
    */

    if (retarray->base_addr == NULL)
    {
        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
        }
        else
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);

            GFC_DIMENSION_SET(retarray->dim[1], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1,
                GFC_DESCRIPTOR_EXTENT(retarray,0));
        }

        retarray->base_addr
            = xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_4));
        retarray->offset = 0;
    }
    else if (unlikely (compile_options.bounds_check))
    {
        index_type ret_extent, arg_extent;

        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 1: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);

            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 2: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
    }


    if (GFC_DESCRIPTOR_RANK (retarray) == 1)
    {
        /* One-dimensional result may be addressed in the code below
        either as a row or a column matrix. We want both cases to
        work. */
        rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
    }
    else
    {
        rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
        rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
    }


    if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        /* Treat it as a a row matrix A[1,count]. */
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = 1;

        xcount = 1;
        count = GFC_DESCRIPTOR_EXTENT(a,0);
    }
    else
    {
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = GFC_DESCRIPTOR_STRIDE(a,1);

        count = GFC_DESCRIPTOR_EXTENT(a,1);
        xcount = GFC_DESCRIPTOR_EXTENT(a,0);
    }

    if (count != GFC_DESCRIPTOR_EXTENT(b,0))
    {
        if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
            runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
    }

    if (GFC_DESCRIPTOR_RANK (b) == 1)
    {
        /* Treat it as a column matrix B[count,1] */
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);

        /* bystride should never be used for 1-dimensional b.
        in case it is we want it to cause a segfault, rather than
        an incorrect result. */
        bystride = 0xDEADBEEF;
        ycount = 1;
    }
    else
    {
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
        bystride = GFC_DESCRIPTOR_STRIDE(b,1);
        ycount = GFC_DESCRIPTOR_EXTENT(b,1);
    }

    abase = a->base_addr;
    bbase = b->base_addr;
    dest = retarray->base_addr;

    /* Now that everything is set up, we perform the multiplication
    itself.  */

#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
#define min(a,b) ((a) <= (b) ? (a) : (b))
#define max(a,b) ((a) >= (b) ? (a) : (b))

    if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
        && (bxstride == 1 || bystride == 1)
        && (((float) xcount) * ((float) ycount) * ((float) count)
        > POW3(blas_limit)))
    {
        const int m = xcount, n = ycount, k = count, ldc = rystride;
        const GFC_INTEGER_4 one = 1, zero = 0;
        const int lda = (axstride == 1) ? aystride : axstride,
            ldb = (bxstride == 1) ? bystride : bxstride;

        if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
        {
            assert (gemm != NULL);
            gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
                &n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
                &ldc, 1, 1);
            return;
        }
    }

    if (rxstride == 1 && axstride == 1 && bxstride == 1)
    {
        /* This block of code implements a tuned matmul, derived from
        Superscalar GEMM-based level 3 BLAS,  Beta version 0.1

        Bo Kagstrom and Per Ling
        Department of Computing Science
        Umea University
        S-901 87 Umea, Sweden

        from netlib.org, translated to C, and modified for matmul.m4.  */

        const GFC_INTEGER_4 *a, *b;
        GFC_INTEGER_4 *c;
        const index_type m = xcount, n = ycount, k = count;

        /* System generated locals */
        index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
            i1, i2, i3, i4, i5, i6;

        /* Local variables */
        GFC_INTEGER_4 t1[65536], /* was [256][256] */
            f11, f12, f21, f22, f31, f32, f41, f42,
            f13, f14, f23, f24, f33, f34, f43, f44;
        index_type i, j, l, ii, jj, ll;
        index_type isec, jsec, lsec, uisec, ujsec, ulsec;

        a = abase;
        b = bbase;
        c = retarray->base_addr;

        /* Parameter adjustments */
        c_dim1 = rystride;
        c_offset = 1 + c_dim1;
        c -= c_offset;
        a_dim1 = aystride;
        a_offset = 1 + a_dim1;
        a -= a_offset;
        b_dim1 = bystride;
        b_offset = 1 + b_dim1;
        b -= b_offset;

        /* Empty c first.  */
        for (j=1; j<=n; j++)
            for (i=1; i<=m; i++)
                c[i + j * c_dim1] = (GFC_INTEGER_4)0;

        /* Early exit if possible */
        if (m == 0 || n == 0 || k == 0)
            return;

        /* Start turning the crank. */
        i1 = n;
        for (jj = 1; jj <= i1; jj += 512)
        {
            /* Computing MIN */
            i2 = 512;
            i3 = n - jj + 1;
            jsec = min(i2,i3);
            ujsec = jsec - jsec % 4;
            i2 = k;
            for (ll = 1; ll <= i2; ll += 256)
            {
                /* Computing MIN */
                i3 = 256;
                i4 = k - ll + 1;
                lsec = min(i3,i4);
                ulsec = lsec - lsec % 2;

                i3 = m;
                for (ii = 1; ii <= i3; ii += 256)
                {
                    /* Computing MIN */
                    i4 = 256;
                    i5 = m - ii + 1;
                    isec = min(i4,i5);
                    uisec = isec - isec % 2;
                    i4 = ll + ulsec - 1;
                    for (l = ll; l <= i4; l += 2)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 2)
                        {
                            t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
                                a[i + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
                                a[i + (l + 1) * a_dim1];
                            t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + (l + 1) * a_dim1];
                        }
                        if (uisec < isec)
                        {
                            t1[l - ll + 1 + (isec << 8) - 257] =
                                a[ii + isec - 1 + l * a_dim1];
                            t1[l - ll + 2 + (isec << 8) - 257] =
                                a[ii + isec - 1 + (l + 1) * a_dim1];
                        }
                    }
                    if (ulsec < lsec)
                    {
                        i4 = ii + isec - 1;
                        for (i = ii; i<= i4; ++i)
                        {
                            t1[lsec + ((i - ii + 1) << 8) - 257] =
                                a[i + (ll + lsec - 1) * a_dim1];
                        }
                    }

                    uisec = isec - isec % 4;
                    i4 = jj + ujsec - 1;
                    for (j = jj; j <= i4; j += 4)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 4)
                        {
                            f11 = c[i + j * c_dim1];
                            f21 = c[i + 1 + j * c_dim1];
                            f12 = c[i + (j + 1) * c_dim1];
                            f22 = c[i + 1 + (j + 1) * c_dim1];
                            f13 = c[i + (j + 2) * c_dim1];
                            f23 = c[i + 1 + (j + 2) * c_dim1];
                            f14 = c[i + (j + 3) * c_dim1];
                            f24 = c[i + 1 + (j + 3) * c_dim1];
                            f31 = c[i + 2 + j * c_dim1];
                            f41 = c[i + 3 + j * c_dim1];
                            f32 = c[i + 2 + (j + 1) * c_dim1];
                            f42 = c[i + 3 + (j + 1) * c_dim1];
                            f33 = c[i + 2 + (j + 2) * c_dim1];
                            f43 = c[i + 3 + (j + 2) * c_dim1];
                            f34 = c[i + 2 + (j + 3) * c_dim1];
                            f44 = c[i + 3 + (j + 3) * c_dim1];
                            i6 = ll + lsec - 1;
                            for (l = ll; l <= i6; ++l)
                            {
                                f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + j * b_dim1];
                                f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + j * b_dim1];
                                f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + j * b_dim1];
                                f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + j * b_dim1];
                                f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                            }
                            c[i + j * c_dim1] = f11;
                            c[i + 1 + j * c_dim1] = f21;
                            c[i + (j + 1) * c_dim1] = f12;
                            c[i + 1 + (j + 1) * c_dim1] = f22;
                            c[i + (j + 2) * c_dim1] = f13;
                            c[i + 1 + (j + 2) * c_dim1] = f23;
                            c[i + (j + 3) * c_dim1] = f14;
                            c[i + 1 + (j + 3) * c_dim1] = f24;
                            c[i + 2 + j * c_dim1] = f31;
                            c[i + 3 + j * c_dim1] = f41;
                            c[i + 2 + (j + 1) * c_dim1] = f32;
                            c[i + 3 + (j + 1) * c_dim1] = f42;
                            c[i + 2 + (j + 2) * c_dim1] = f33;
                            c[i + 3 + (j + 2) * c_dim1] = f43;
                            c[i + 2 + (j + 3) * c_dim1] = f34;
                            c[i + 3 + (j + 3) * c_dim1] = f44;
                        }
                        if (uisec < isec)
                        {
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                f12 = c[i + (j + 1) * c_dim1];
                                f13 = c[i + (j + 2) * c_dim1];
                                f14 = c[i + (j + 3) * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 1) * b_dim1];
                                    f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 2) * b_dim1];
                                    f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 3) * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + (j + 1) * c_dim1] = f12;
                                c[i + (j + 2) * c_dim1] = f13;
                                c[i + (j + 3) * c_dim1] = f14;
                            }
                        }
                    }
                    if (ujsec < jsec)
                    {
                        i4 = jj + jsec - 1;
                        for (j = jj + ujsec; j <= i4; ++j)
                        {
                            i5 = ii + uisec - 1;
                            for (i = ii; i <= i5; i += 4)
                            {
                                f11 = c[i + j * c_dim1];
                                f21 = c[i + 1 + j * c_dim1];
                                f31 = c[i + 2 + j * c_dim1];
                                f41 = c[i + 3 + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + 1 + j * c_dim1] = f21;
                                c[i + 2 + j * c_dim1] = f31;
                                c[i + 3 + j * c_dim1] = f41;
                            }
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                            }
                        }
                    }
                }
            }
        }
        return;
    }
    else if (rxstride == 1 && aystride == 1 && bxstride == 1)
    {
        if (GFC_DESCRIPTOR_RANK (a) != 1)
        {
            const GFC_INTEGER_4 *restrict abase_x;
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 *restrict dest_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                dest_y = &dest[y*rystride];
                for (x = 0; x < xcount; x++)
                {
                    abase_x = &abase[x*axstride];
                    s = (GFC_INTEGER_4) 0;
                    for (n = 0; n < count; n++)
                        s += abase_x[n] * bbase_y[n];
                    dest_y[x] = s;
                }
            }
        }
        else
        {
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase[n*axstride] * bbase_y[n];
                dest[y*rystride] = s;
            }
        }
    }
    // else if (axstride < aystride)
    //   {
    //     for (y = 0; y < ycount; y++)
    //for (x = 0; x < xcount; x++)
    //  dest[x*rxstride + y*rystride] = (GFC_INTEGER_4)0;

    //     for (y = 0; y < ycount; y++)
    //for (n = 0; n < count; n++)
    //  for (x = 0; x < xcount; x++)
    //    /* dest[x,y] += a[x,n] * b[n,y] */
    //    dest[x*rxstride + y*rystride] +=
    //				abase[x*axstride + n*aystride] *
    //				bbase[n*bxstride + y*bystride];
    //   }
    else if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            s = (GFC_INTEGER_4) 0;
            for (n = 0; n < count; n++)
                s += abase[n*axstride] * bbase_y[n*bxstride];
            dest[y*rxstride] = s;
        }
    }
    else
    {
        const GFC_INTEGER_4 *restrict abase_x;
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 *restrict dest_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            dest_y = &dest[y*rystride];
            for (x = 0; x < xcount; x++)
            {
                abase_x = &abase[x*axstride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase_x[n*aystride] * bbase_y[n*bxstride];
                dest_y[x*rxstride] = s;
            }
        }
    }
}
#undef POW3
#undef min
#undef max

#endif  /* HAVE_AVX512F */

/* Function to fall back to if there is no special processor-specific version.  */
static void
    matmul_i4_vanilla (gfc_array_i4 * const restrict retarray, 
    gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
    int blas_limit, blas_call gemm)
{
    const GFC_INTEGER_4 * restrict abase;
    const GFC_INTEGER_4 * restrict bbase;
    GFC_INTEGER_4 * restrict dest;

    index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
    index_type x, y, n, count, xcount, ycount;

    assert (GFC_DESCRIPTOR_RANK (a) == 2
        || GFC_DESCRIPTOR_RANK (b) == 2);

    /* C[xcount,ycount] = A[xcount, count] * B[count,ycount]

    Either A or B (but not both) can be rank 1:

    o One-dimensional argument A is implicitly treated as a row matrix
    dimensioned [1,count], so xcount=1.

    o One-dimensional argument B is implicitly treated as a column matrix
    dimensioned [count, 1], so ycount=1.
    */

    if (retarray->base_addr == NULL)
    {
        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
        }
        else
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);

            GFC_DIMENSION_SET(retarray->dim[1], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1,
                GFC_DESCRIPTOR_EXTENT(retarray,0));
        }

        retarray->base_addr
            = xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_4));
        retarray->offset = 0;
    }
    else if (unlikely (compile_options.bounds_check))
    {
        index_type ret_extent, arg_extent;

        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 1: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);

            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 2: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
    }


    if (GFC_DESCRIPTOR_RANK (retarray) == 1)
    {
        /* One-dimensional result may be addressed in the code below
        either as a row or a column matrix. We want both cases to
        work. */
        rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
    }
    else
    {
        rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
        rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
    }


    if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        /* Treat it as a a row matrix A[1,count]. */
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = 1;

        xcount = 1;
        count = GFC_DESCRIPTOR_EXTENT(a,0);
    }
    else
    {
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = GFC_DESCRIPTOR_STRIDE(a,1);

        count = GFC_DESCRIPTOR_EXTENT(a,1);
        xcount = GFC_DESCRIPTOR_EXTENT(a,0);
    }

    if (count != GFC_DESCRIPTOR_EXTENT(b,0))
    {
        if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
            runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
    }

    if (GFC_DESCRIPTOR_RANK (b) == 1)
    {
        /* Treat it as a column matrix B[count,1] */
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);

        /* bystride should never be used for 1-dimensional b.
        in case it is we want it to cause a segfault, rather than
        an incorrect result. */
        bystride = 0xDEADBEEF;
        ycount = 1;
    }
    else
    {
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
        bystride = GFC_DESCRIPTOR_STRIDE(b,1);
        ycount = GFC_DESCRIPTOR_EXTENT(b,1);
    }

    abase = a->base_addr;
    bbase = b->base_addr;
    dest = retarray->base_addr;

    /* Now that everything is set up, we perform the multiplication
    itself.  */

#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
#define min(a,b) ((a) <= (b) ? (a) : (b))
#define max(a,b) ((a) >= (b) ? (a) : (b))

    if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
        && (bxstride == 1 || bystride == 1)
        && (((float) xcount) * ((float) ycount) * ((float) count)
        > POW3(blas_limit)))
    {
        const int m = xcount, n = ycount, k = count, ldc = rystride;
        const GFC_INTEGER_4 one = 1, zero = 0;
        const int lda = (axstride == 1) ? aystride : axstride,
            ldb = (bxstride == 1) ? bystride : bxstride;

        if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
        {
            assert (gemm != NULL);
            gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
                &n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
                &ldc, 1, 1);
            return;
        }
    }

    if (rxstride == 1 && axstride == 1 && bxstride == 1)
    {
        /* This block of code implements a tuned matmul, derived from
        Superscalar GEMM-based level 3 BLAS,  Beta version 0.1

        Bo Kagstrom and Per Ling
        Department of Computing Science
        Umea University
        S-901 87 Umea, Sweden

        from netlib.org, translated to C, and modified for matmul.m4.  */

        const GFC_INTEGER_4 *a, *b;
        GFC_INTEGER_4 *c;
        const index_type m = xcount, n = ycount, k = count;

        /* System generated locals */
        index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
            i1, i2, i3, i4, i5, i6;

        /* Local variables */
        GFC_INTEGER_4 t1[65536], /* was [256][256] */
            f11, f12, f21, f22, f31, f32, f41, f42,
            f13, f14, f23, f24, f33, f34, f43, f44;
        index_type i, j, l, ii, jj, ll;
        index_type isec, jsec, lsec, uisec, ujsec, ulsec;

        a = abase;
        b = bbase;
        c = retarray->base_addr;

        /* Parameter adjustments */
        c_dim1 = rystride;
        c_offset = 1 + c_dim1;
        c -= c_offset;
        a_dim1 = aystride;
        a_offset = 1 + a_dim1;
        a -= a_offset;
        b_dim1 = bystride;
        b_offset = 1 + b_dim1;
        b -= b_offset;

        /* Empty c first.  */
        for (j=1; j<=n; j++)
            for (i=1; i<=m; i++)
                c[i + j * c_dim1] = (GFC_INTEGER_4)0;

        /* Early exit if possible */
        if (m == 0 || n == 0 || k == 0)
            return;

        /* Start turning the crank. */
        i1 = n;
        for (jj = 1; jj <= i1; jj += 512)
        {
            /* Computing MIN */
            i2 = 512;
            i3 = n - jj + 1;
            jsec = min(i2,i3);
            ujsec = jsec - jsec % 4;
            i2 = k;
            for (ll = 1; ll <= i2; ll += 256)
            {
                /* Computing MIN */
                i3 = 256;
                i4 = k - ll + 1;
                lsec = min(i3,i4);
                ulsec = lsec - lsec % 2;

                i3 = m;
                for (ii = 1; ii <= i3; ii += 256)
                {
                    /* Computing MIN */
                    i4 = 256;
                    i5 = m - ii + 1;
                    isec = min(i4,i5);
                    uisec = isec - isec % 2;
                    i4 = ll + ulsec - 1;
                    for (l = ll; l <= i4; l += 2)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 2)
                        {
                            t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
                                a[i + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
                                a[i + (l + 1) * a_dim1];
                            t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + (l + 1) * a_dim1];
                        }
                        if (uisec < isec)
                        {
                            t1[l - ll + 1 + (isec << 8) - 257] =
                                a[ii + isec - 1 + l * a_dim1];
                            t1[l - ll + 2 + (isec << 8) - 257] =
                                a[ii + isec - 1 + (l + 1) * a_dim1];
                        }
                    }
                    if (ulsec < lsec)
                    {
                        i4 = ii + isec - 1;
                        for (i = ii; i<= i4; ++i)
                        {
                            t1[lsec + ((i - ii + 1) << 8) - 257] =
                                a[i + (ll + lsec - 1) * a_dim1];
                        }
                    }

                    uisec = isec - isec % 4;
                    i4 = jj + ujsec - 1;
                    for (j = jj; j <= i4; j += 4)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 4)
                        {
                            f11 = c[i + j * c_dim1];
                            f21 = c[i + 1 + j * c_dim1];
                            f12 = c[i + (j + 1) * c_dim1];
                            f22 = c[i + 1 + (j + 1) * c_dim1];
                            f13 = c[i + (j + 2) * c_dim1];
                            f23 = c[i + 1 + (j + 2) * c_dim1];
                            f14 = c[i + (j + 3) * c_dim1];
                            f24 = c[i + 1 + (j + 3) * c_dim1];
                            f31 = c[i + 2 + j * c_dim1];
                            f41 = c[i + 3 + j * c_dim1];
                            f32 = c[i + 2 + (j + 1) * c_dim1];
                            f42 = c[i + 3 + (j + 1) * c_dim1];
                            f33 = c[i + 2 + (j + 2) * c_dim1];
                            f43 = c[i + 3 + (j + 2) * c_dim1];
                            f34 = c[i + 2 + (j + 3) * c_dim1];
                            f44 = c[i + 3 + (j + 3) * c_dim1];
                            i6 = ll + lsec - 1;
                            for (l = ll; l <= i6; ++l)
                            {
                                f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + j * b_dim1];
                                f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + j * b_dim1];
                                f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + j * b_dim1];
                                f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + j * b_dim1];
                                f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                            }
                            c[i + j * c_dim1] = f11;
                            c[i + 1 + j * c_dim1] = f21;
                            c[i + (j + 1) * c_dim1] = f12;
                            c[i + 1 + (j + 1) * c_dim1] = f22;
                            c[i + (j + 2) * c_dim1] = f13;
                            c[i + 1 + (j + 2) * c_dim1] = f23;
                            c[i + (j + 3) * c_dim1] = f14;
                            c[i + 1 + (j + 3) * c_dim1] = f24;
                            c[i + 2 + j * c_dim1] = f31;
                            c[i + 3 + j * c_dim1] = f41;
                            c[i + 2 + (j + 1) * c_dim1] = f32;
                            c[i + 3 + (j + 1) * c_dim1] = f42;
                            c[i + 2 + (j + 2) * c_dim1] = f33;
                            c[i + 3 + (j + 2) * c_dim1] = f43;
                            c[i + 2 + (j + 3) * c_dim1] = f34;
                            c[i + 3 + (j + 3) * c_dim1] = f44;
                        }
                        if (uisec < isec)
                        {
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                f12 = c[i + (j + 1) * c_dim1];
                                f13 = c[i + (j + 2) * c_dim1];
                                f14 = c[i + (j + 3) * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 1) * b_dim1];
                                    f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 2) * b_dim1];
                                    f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 3) * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + (j + 1) * c_dim1] = f12;
                                c[i + (j + 2) * c_dim1] = f13;
                                c[i + (j + 3) * c_dim1] = f14;
                            }
                        }
                    }
                    if (ujsec < jsec)
                    {
                        i4 = jj + jsec - 1;
                        for (j = jj + ujsec; j <= i4; ++j)
                        {
                            i5 = ii + uisec - 1;
                            for (i = ii; i <= i5; i += 4)
                            {
                                f11 = c[i + j * c_dim1];
                                f21 = c[i + 1 + j * c_dim1];
                                f31 = c[i + 2 + j * c_dim1];
                                f41 = c[i + 3 + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + 1 + j * c_dim1] = f21;
                                c[i + 2 + j * c_dim1] = f31;
                                c[i + 3 + j * c_dim1] = f41;
                            }
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                            }
                        }
                    }
                }
            }
        }
        return;
    }
    else if (rxstride == 1 && aystride == 1 && bxstride == 1)
    {
        if (GFC_DESCRIPTOR_RANK (a) != 1)
        {
            const GFC_INTEGER_4 *restrict abase_x;
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 *restrict dest_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                dest_y = &dest[y*rystride];
                for (x = 0; x < xcount; x++)
                {
                    abase_x = &abase[x*axstride];
                    s = (GFC_INTEGER_4) 0;
                    for (n = 0; n < count; n++)
                        s += abase_x[n] * bbase_y[n];
                    dest_y[x] = s;
                }
            }
        }
        else
        {
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase[n*axstride] * bbase_y[n];
                dest[y*rystride] = s;
            }
        }
    }
    // else if (axstride < aystride)
    //   {
    //     for (y = 0; y < ycount; y++)
    //for (x = 0; x < xcount; x++)
    //  dest[x*rxstride + y*rystride] = (GFC_INTEGER_4)0;

    //     for (y = 0; y < ycount; y++)
    //for (n = 0; n < count; n++)
    //  for (x = 0; x < xcount; x++)
    //    /* dest[x,y] += a[x,n] * b[n,y] */
    //    dest[x*rxstride + y*rystride] +=
    //				abase[x*axstride + n*aystride] *
    //				bbase[n*bxstride + y*bystride];
    //   }
    else if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            s = (GFC_INTEGER_4) 0;
            for (n = 0; n < count; n++)
                s += abase[n*axstride] * bbase_y[n*bxstride];
            dest[y*rxstride] = s;
        }
    }
    else
    {
        const GFC_INTEGER_4 *restrict abase_x;
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 *restrict dest_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            dest_y = &dest[y*rystride];
            for (x = 0; x < xcount; x++)
            {
                abase_x = &abase[x*axstride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase_x[n*aystride] * bbase_y[n*bxstride];
                dest_y[x*rxstride] = s;
            }
        }
    }
}
#undef POW3
#undef min
#undef max


/* Compiling main function, with selection code for the processor.  */

/* Currently, this is i386 only.  Adjust for other architectures.  */

#include <config/i386/cpuinfo.h>
void matmul_i4 (gfc_array_i4 * const restrict retarray, 
                gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
                int blas_limit, blas_call gemm)
{
    static void (*matmul_p) (gfc_array_i4 * const restrict retarray, 
        gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
        int blas_limit, blas_call gemm);

    void (*matmul_fn) (gfc_array_i4 * const restrict retarray, 
        gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
        int blas_limit, blas_call gemm);

    matmul_fn = __atomic_load_n (&matmul_p, __ATOMIC_RELAXED);
    if (matmul_fn == NULL)
    {
        matmul_fn = matmul_i4_vanilla;
        if (__cpu_model.__cpu_vendor == VENDOR_INTEL)
        {
            /* Run down the available processors in order of preference.  */
#ifdef HAVE_AVX512F
            if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX512F))
            {
                matmul_fn = matmul_i4_avx512f;
                goto store;
            }

#endif  /* HAVE_AVX512F */

#ifdef HAVE_AVX2
            if ((__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX2))
                && (__cpu_model.__cpu_features[0] & (1 << FEATURE_FMA)))
            {
                matmul_fn = matmul_i4_avx2;
                goto store;
            }

#endif

#ifdef HAVE_AVX
            if (__cpu_model.__cpu_features[0] & (1 << FEATURE_AVX))
            {
                matmul_fn = matmul_i4_avx;
                goto store;
            }
#endif  /* HAVE_AVX */
        }
store:
        __atomic_store_n (&matmul_p, matmul_fn, __ATOMIC_RELAXED);
    }

    (*matmul_fn) (retarray, a, b, try_blas, blas_limit, gemm);
}

#else  /* Just the vanilla function.  */

void
    matmul_i4 (gfc_array_i4 * const restrict retarray, 
    gfc_array_i4 * const restrict a, gfc_array_i4 * const restrict b, int try_blas,
    int blas_limit, blas_call gemm)
{
    const GFC_INTEGER_4 * restrict abase;
    const GFC_INTEGER_4 * restrict bbase;
    GFC_INTEGER_4 * restrict dest;

    index_type rxstride, rystride, axstride, aystride, bxstride, bystride;
    index_type x, y, n, count, xcount, ycount;

    assert (GFC_DESCRIPTOR_RANK (a) == 2
        || GFC_DESCRIPTOR_RANK (b) == 2);

    /* C[xcount,ycount] = A[xcount, count] * B[count,ycount]

    Either A or B (but not both) can be rank 1:

    o One-dimensional argument A is implicitly treated as a row matrix
    dimensioned [1,count], so xcount=1.

    o One-dimensional argument B is implicitly treated as a column matrix
    dimensioned [count, 1], so ycount=1.
    */

    if (retarray->base_addr == NULL)
    {
        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1, 1);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);
        }
        else
        {
            GFC_DIMENSION_SET(retarray->dim[0], 0,
                GFC_DESCRIPTOR_EXTENT(a,0) - 1, 1);

            GFC_DIMENSION_SET(retarray->dim[1], 0,
                GFC_DESCRIPTOR_EXTENT(b,1) - 1,
                GFC_DESCRIPTOR_EXTENT(retarray,0));
        }

        retarray->base_addr
            = xmallocarray (size0 ((array_t *) retarray), sizeof (GFC_INTEGER_4));
        retarray->offset = 0;
    }
    else if (unlikely (compile_options.bounds_check))
    {
        index_type ret_extent, arg_extent;

        if (GFC_DESCRIPTOR_RANK (a) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else if (GFC_DESCRIPTOR_RANK (b) == 1)
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
        else
        {
            arg_extent = GFC_DESCRIPTOR_EXTENT(a,0);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,0);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 1: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);

            arg_extent = GFC_DESCRIPTOR_EXTENT(b,1);
            ret_extent = GFC_DESCRIPTOR_EXTENT(retarray,1);
            if (arg_extent != ret_extent)
                runtime_error ("Incorrect extent in return array in MATMUL intrinsic for dimension 2: is %ld, should be %ld",
                (long int) ret_extent, (long int) arg_extent);
        }
    }


    if (GFC_DESCRIPTOR_RANK (retarray) == 1)
    {
        /* One-dimensional result may be addressed in the code below
        either as a row or a column matrix. We want both cases to
        work. */
        rxstride = rystride = GFC_DESCRIPTOR_STRIDE(retarray,0);
    }
    else
    {
        rxstride = GFC_DESCRIPTOR_STRIDE(retarray,0);
        rystride = GFC_DESCRIPTOR_STRIDE(retarray,1);
    }


    if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        /* Treat it as a a row matrix A[1,count]. */
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = 1;

        xcount = 1;
        count = GFC_DESCRIPTOR_EXTENT(a,0);
    }
    else
    {
        axstride = GFC_DESCRIPTOR_STRIDE(a,0);
        aystride = GFC_DESCRIPTOR_STRIDE(a,1);

        count = GFC_DESCRIPTOR_EXTENT(a,1);
        xcount = GFC_DESCRIPTOR_EXTENT(a,0);
    }

    if (count != GFC_DESCRIPTOR_EXTENT(b,0))
    {
        if (count > 0 || GFC_DESCRIPTOR_EXTENT(b,0) > 0)
            runtime_error ("dimension of array B incorrect in MATMUL intrinsic");
    }

    if (GFC_DESCRIPTOR_RANK (b) == 1)
    {
        /* Treat it as a column matrix B[count,1] */
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);

        /* bystride should never be used for 1-dimensional b.
        in case it is we want it to cause a segfault, rather than
        an incorrect result. */
        bystride = 0xDEADBEEF;
        ycount = 1;
    }
    else
    {
        bxstride = GFC_DESCRIPTOR_STRIDE(b,0);
        bystride = GFC_DESCRIPTOR_STRIDE(b,1);
        ycount = GFC_DESCRIPTOR_EXTENT(b,1);
    }

    abase = a->base_addr;
    bbase = b->base_addr;
    dest = retarray->base_addr;

    /* Now that everything is set up, we perform the multiplication
    itself.  */

#define POW3(x) (((float) (x)) * ((float) (x)) * ((float) (x)))
#define min(a,b) ((a) <= (b) ? (a) : (b))
#define max(a,b) ((a) >= (b) ? (a) : (b))

    if (try_blas && rxstride == 1 && (axstride == 1 || aystride == 1)
        && (bxstride == 1 || bystride == 1)
        && (((float) xcount) * ((float) ycount) * ((float) count)
          > POW3(blas_limit)))
    {
        const int m = xcount, n = ycount, k = count, ldc = rystride;
        const GFC_INTEGER_4 one = 1, zero = 0;
        const int lda = (axstride == 1) ? aystride : axstride,
            ldb = (bxstride == 1) ? bystride : bxstride;

        if (lda > 0 && ldb > 0 && ldc > 0 && m > 1 && n > 1 && k > 1)
        {
            assert (gemm != NULL);
            gemm (axstride == 1 ? "N" : "T", bxstride == 1 ? "N" : "T", &m,
                &n, &k,	&one, abase, &lda, bbase, &ldb, &zero, dest,
                &ldc, 1, 1);
            return;
        }
    }

    if (rxstride == 1 && axstride == 1 && bxstride == 1)
    {
        /* This block of code implements a tuned matmul, derived from
        Superscalar GEMM-based level 3 BLAS,  Beta version 0.1

        Bo Kagstrom and Per Ling
        Department of Computing Science
        Umea University
        S-901 87 Umea, Sweden

        from netlib.org, translated to C, and modified for matmul.m4.  */

        const GFC_INTEGER_4 *a, *b;
        GFC_INTEGER_4 *c;
        const index_type m = xcount, n = ycount, k = count;

        /* System generated locals */
        index_type a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset,
            i1, i2, i3, i4, i5, i6;

        /* Local variables */
        GFC_INTEGER_4 t1[65536], /* was [256][256] */
            f11, f12, f21, f22, f31, f32, f41, f42,
            f13, f14, f23, f24, f33, f34, f43, f44;
        index_type i, j, l, ii, jj, ll;
        index_type isec, jsec, lsec, uisec, ujsec, ulsec;

        a = abase;
        b = bbase;
        c = retarray->base_addr;

        /* Parameter adjustments */
        c_dim1 = rystride;
        c_offset = 1 + c_dim1;
        c -= c_offset;
        a_dim1 = aystride;
        a_offset = 1 + a_dim1;
        a -= a_offset;
        b_dim1 = bystride;
        b_offset = 1 + b_dim1;
        b -= b_offset;

        /* Empty c first.  */
        for (j=1; j<=n; j++)
            for (i=1; i<=m; i++)
                c[i + j * c_dim1] = (GFC_INTEGER_4)0;

        /* Early exit if possible */
        if (m == 0 || n == 0 || k == 0)

            return;
        /* Start turning the crank. */
        i1 = n;
        for (jj = 1; jj <= i1; jj += 512)
        {
            /* Computing MIN */
            i2 = 512;
            i3 = n - jj + 1;
            jsec = min(i2,i3);
            ujsec = jsec - jsec % 4;
            i2 = k;
            for (ll = 1; ll <= i2; ll += 256)
            {
                /* Computing MIN */
                i3 = 256;
                i4 = k - ll + 1;
                lsec = min(i3,i4);
                ulsec = lsec - lsec % 2;

                i3 = m;
                for (ii = 1; ii <= i3; ii += 256)
                {
                    /* Computing MIN */
                    i4 = 256;
                    i5 = m - ii + 1;
                    isec = min(i4,i5);
                    uisec = isec - isec % 2;
                    i4 = ll + ulsec - 1;
                    for (l = ll; l <= i4; l += 2)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 2)
                        {
                            t1[l - ll + 1 + ((i - ii + 1) << 8) - 257] =
                                a[i + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 1) << 8) - 257] =
                                a[i + (l + 1) * a_dim1];
                            t1[l - ll + 1 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + l * a_dim1];
                            t1[l - ll + 2 + ((i - ii + 2) << 8) - 257] =
                                a[i + 1 + (l + 1) * a_dim1];
                        }
                        if (uisec < isec)
                        {
                            t1[l - ll + 1 + (isec << 8) - 257] =
                                a[ii + isec - 1 + l * a_dim1];
                            t1[l - ll + 2 + (isec << 8) - 257] =
                                a[ii + isec - 1 + (l + 1) * a_dim1];
                        }
                    }
                    if (ulsec < lsec)
                    {
                        i4 = ii + isec - 1;
                        for (i = ii; i<= i4; ++i)
                        {
                            t1[lsec + ((i - ii + 1) << 8) - 257] =
                                a[i + (ll + lsec - 1) * a_dim1];
                        }
                    }

                    uisec = isec - isec % 4;
                    i4 = jj + ujsec - 1;
                    for (j = jj; j <= i4; j += 4)
                    {
                        i5 = ii + uisec - 1;
                        for (i = ii; i <= i5; i += 4)
                        {
                            f11 = c[i + j * c_dim1];
                            f21 = c[i + 1 + j * c_dim1];
                            f12 = c[i + (j + 1) * c_dim1];
                            f22 = c[i + 1 + (j + 1) * c_dim1];
                            f13 = c[i + (j + 2) * c_dim1];
                            f23 = c[i + 1 + (j + 2) * c_dim1];
                            f14 = c[i + (j + 3) * c_dim1];
                            f24 = c[i + 1 + (j + 3) * c_dim1];
                            f31 = c[i + 2 + j * c_dim1];
                            f41 = c[i + 3 + j * c_dim1];
                            f32 = c[i + 2 + (j + 1) * c_dim1];
                            f42 = c[i + 3 + (j + 1) * c_dim1];
                            f33 = c[i + 2 + (j + 2) * c_dim1];
                            f43 = c[i + 3 + (j + 2) * c_dim1];
                            f34 = c[i + 2 + (j + 3) * c_dim1];
                            f44 = c[i + 3 + (j + 3) * c_dim1];
                            i6 = ll + lsec - 1;
                            for (l = ll; l <= i6; ++l)
                            {
                                f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + j * b_dim1];
                                f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + j * b_dim1];
                                f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f22 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f23 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f24 += t1[l - ll + 1 + ((i - ii + 2) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + j * b_dim1];
                                f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + j * b_dim1];
                                f32 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f42 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 1) * b_dim1];
                                f33 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f43 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 2) * b_dim1];
                                f34 += t1[l - ll + 1 + ((i - ii + 3) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                                f44 += t1[l - ll + 1 + ((i - ii + 4) << 8) - 257]
                                * b[l + (j + 3) * b_dim1];
                            }
                            c[i + j * c_dim1] = f11;
                            c[i + 1 + j * c_dim1] = f21;
                            c[i + (j + 1) * c_dim1] = f12;
                            c[i + 1 + (j + 1) * c_dim1] = f22;
                            c[i + (j + 2) * c_dim1] = f13;
                            c[i + 1 + (j + 2) * c_dim1] = f23;
                            c[i + (j + 3) * c_dim1] = f14;
                            c[i + 1 + (j + 3) * c_dim1] = f24;
                            c[i + 2 + j * c_dim1] = f31;
                            c[i + 3 + j * c_dim1] = f41;
                            c[i + 2 + (j + 1) * c_dim1] = f32;
                            c[i + 3 + (j + 1) * c_dim1] = f42;
                            c[i + 2 + (j + 2) * c_dim1] = f33;
                            c[i + 3 + (j + 2) * c_dim1] = f43;
                            c[i + 2 + (j + 3) * c_dim1] = f34;
                            c[i + 3 + (j + 3) * c_dim1] = f44;
                        }
                        if (uisec < isec)
                        {
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                f12 = c[i + (j + 1) * c_dim1];
                                f13 = c[i + (j + 2) * c_dim1];
                                f14 = c[i + (j + 3) * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f12 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 1) * b_dim1];
                                    f13 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 2) * b_dim1];
                                    f14 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + (j + 3) * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + (j + 1) * c_dim1] = f12;
                                c[i + (j + 2) * c_dim1] = f13;
                                c[i + (j + 3) * c_dim1] = f14;
                            }
                        }
                    }
                    if (ujsec < jsec)
                    {
                        i4 = jj + jsec - 1;
                        for (j = jj + ujsec; j <= i4; ++j)
                        {
                            i5 = ii + uisec - 1;
                            for (i = ii; i <= i5; i += 4)
                            {
                                f11 = c[i + j * c_dim1];
                                f21 = c[i + 1 + j * c_dim1];
                                f31 = c[i + 2 + j * c_dim1];
                                f41 = c[i + 3 + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f21 += t1[l - ll + 1 + ((i - ii + 2) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f31 += t1[l - ll + 1 + ((i - ii + 3) << 8) -
                                        257] * b[l + j * b_dim1];
                                    f41 += t1[l - ll + 1 + ((i - ii + 4) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                                c[i + 1 + j * c_dim1] = f21;
                                c[i + 2 + j * c_dim1] = f31;
                                c[i + 3 + j * c_dim1] = f41;
                            }
                            i5 = ii + isec - 1;
                            for (i = ii + uisec; i <= i5; ++i)
                            {
                                f11 = c[i + j * c_dim1];
                                i6 = ll + lsec - 1;
                                for (l = ll; l <= i6; ++l)
                                {
                                    f11 += t1[l - ll + 1 + ((i - ii + 1) << 8) -
                                        257] * b[l + j * b_dim1];
                                }
                                c[i + j * c_dim1] = f11;
                            }
                        }
                    }
                }
            }
        }
        return;
    }
    else if (rxstride == 1 && aystride == 1 && bxstride == 1)
    {
        if (GFC_DESCRIPTOR_RANK (a) != 1)
        {
            const GFC_INTEGER_4 *restrict abase_x;
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 *restrict dest_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                dest_y = &dest[y*rystride];
                for (x = 0; x < xcount; x++)
                {
                    abase_x = &abase[x*axstride];
                    s = (GFC_INTEGER_4) 0;
                    for (n = 0; n < count; n++)
                        s += abase_x[n] * bbase_y[n];
                    dest_y[x] = s;
                }
            }
        }
        else
        {
            const GFC_INTEGER_4 *restrict bbase_y;
            GFC_INTEGER_4 s;

            for (y = 0; y < ycount; y++)
            {
                bbase_y = &bbase[y*bystride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase[n*axstride] * bbase_y[n];
                dest[y*rystride] = s;
            }
        }
    }
    // else if (axstride < aystride)
    //   {
    //     for (y = 0; y < ycount; y++)
    //for (x = 0; x < xcount; x++)
    //  dest[x*rxstride + y*rystride] = (GFC_INTEGER_4)0;

    //     for (y = 0; y < ycount; y++)
    //for (n = 0; n < count; n++)
    //  for (x = 0; x < xcount; x++)
    //    /* dest[x,y] += a[x,n] * b[n,y] */
    //    dest[x*rxstride + y*rystride] +=
    //				abase[x*axstride + n*aystride] *
    //				bbase[n*bxstride + y*bystride];
    //   }
    else if (GFC_DESCRIPTOR_RANK (a) == 1)
    {
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            s = (GFC_INTEGER_4) 0;
            for (n = 0; n < count; n++)
                s += abase[n*axstride] * bbase_y[n*bxstride];
            dest[y*rxstride] = s;
        }
    }
    else
    {
        const GFC_INTEGER_4 *restrict abase_x;
        const GFC_INTEGER_4 *restrict bbase_y;
        GFC_INTEGER_4 *restrict dest_y;
        GFC_INTEGER_4 s;

        for (y = 0; y < ycount; y++)
        {
            bbase_y = &bbase[y*bystride];
            dest_y = &dest[y*rystride];
            for (x = 0; x < xcount; x++)
            {
                abase_x = &abase[x*axstride];
                s = (GFC_INTEGER_4) 0;
                for (n = 0; n < count; n++)
                    s += abase_x[n*aystride] * bbase_y[n*bxstride];
                dest_y[x*rxstride] = s;
            }
        }
    }
}
#undef POW3
#undef min
#undef max

#endif
#endif