summaryrefslogtreecommitdiff
path: root/mpi/generic
diff options
context:
space:
mode:
Diffstat (limited to 'mpi/generic')
-rw-r--r--mpi/generic/distfiles10
-rw-r--r--mpi/generic/mpi-asm-defs.h10
-rw-r--r--mpi/generic/mpih-add1.c66
-rw-r--r--mpi/generic/mpih-lshift.c70
-rw-r--r--mpi/generic/mpih-mul1.c62
-rw-r--r--mpi/generic/mpih-mul2.c67
-rw-r--r--mpi/generic/mpih-mul3.c68
-rw-r--r--mpi/generic/mpih-rshift.c69
-rw-r--r--mpi/generic/mpih-sub1.c66
-rw-r--r--mpi/generic/udiv-w-sdiv.c134
10 files changed, 622 insertions, 0 deletions
diff --git a/mpi/generic/distfiles b/mpi/generic/distfiles
new file mode 100644
index 0000000..649e829
--- /dev/null
+++ b/mpi/generic/distfiles
@@ -0,0 +1,10 @@
+mpih-add1.c
+mpih-mul1.c
+mpih-mul2.c
+mpih-mul3.c
+mpih-lshift.c
+mpih-rshift.c
+mpih-sub1.c
+udiv-w-sdiv.c
+mpi-asm-defs.h
+
diff --git a/mpi/generic/mpi-asm-defs.h b/mpi/generic/mpi-asm-defs.h
new file mode 100644
index 0000000..13424e2
--- /dev/null
+++ b/mpi/generic/mpi-asm-defs.h
@@ -0,0 +1,10 @@
+/* This file defines some basic constants for the MPI machinery. We
+ * need to define the types on a per-CPU basis, so it is done with
+ * this file here. */
+#define BYTES_PER_MPI_LIMB (SIZEOF_UNSIGNED_LONG)
+
+
+
+
+
+
diff --git a/mpi/generic/mpih-add1.c b/mpi/generic/mpih-add1.c
new file mode 100644
index 0000000..ebcd132
--- /dev/null
+++ b/mpi/generic/mpih-add1.c
@@ -0,0 +1,66 @@
+/* mpihelp-add_1.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998,
+ * 2000 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+mpi_limb_t
+mpihelp_add_n( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_ptr_t s2_ptr, mpi_size_t size)
+{
+ mpi_limb_t x, y, cy;
+ mpi_size_t j;
+
+ /* The loop counter and index J goes from -SIZE to -1. This way
+ the loop becomes faster. */
+ j = -size;
+
+ /* Offset the base pointers to compensate for the negative indices. */
+ s1_ptr -= j;
+ s2_ptr -= j;
+ res_ptr -= j;
+
+ cy = 0;
+ do {
+ y = s2_ptr[j];
+ x = s1_ptr[j];
+ y += cy; /* add previous carry to one addend */
+ cy = y < cy; /* get out carry from that addition */
+ y += x; /* add other addend */
+ cy += y < x; /* get out carry from that add, combine */
+ res_ptr[j] = y;
+ } while( ++j );
+
+ return cy;
+}
+
diff --git a/mpi/generic/mpih-lshift.c b/mpi/generic/mpih-lshift.c
new file mode 100644
index 0000000..e55cb49
--- /dev/null
+++ b/mpi/generic/mpih-lshift.c
@@ -0,0 +1,70 @@
+/* mpihelp-lshift.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+
+/* Shift U (pointed to by UP and USIZE digits long) CNT bits to the left
+ * and store the USIZE least significant digits of the result at WP.
+ * Return the bits shifted out from the most significant digit.
+ *
+ * Argument constraints:
+ * 1. 0 < CNT < BITS_PER_MP_LIMB
+ * 2. If the result is to be written over the input, WP must be >= UP.
+ */
+
+mpi_limb_t
+mpihelp_lshift( mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
+ unsigned int cnt)
+{
+ mpi_limb_t high_limb, low_limb;
+ unsigned sh_1, sh_2;
+ mpi_size_t i;
+ mpi_limb_t retval;
+
+ sh_1 = cnt;
+ wp += 1;
+ sh_2 = BITS_PER_MPI_LIMB - sh_1;
+ i = usize - 1;
+ low_limb = up[i];
+ retval = low_limb >> sh_2;
+ high_limb = low_limb;
+ while( --i >= 0 ) {
+ low_limb = up[i];
+ wp[i] = (high_limb << sh_1) | (low_limb >> sh_2);
+ high_limb = low_limb;
+ }
+ wp[i] = high_limb << sh_1;
+
+ return retval;
+}
+
+
diff --git a/mpi/generic/mpih-mul1.c b/mpi/generic/mpih-mul1.c
new file mode 100644
index 0000000..2c5c4ae
--- /dev/null
+++ b/mpi/generic/mpih-mul1.c
@@ -0,0 +1,62 @@
+/* mpihelp-mul_1.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+mpi_limb_t
+mpihelp_mul_1( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_size_t s1_size,
+ mpi_limb_t s2_limb)
+{
+ mpi_limb_t cy_limb;
+ mpi_size_t j;
+ mpi_limb_t prod_high, prod_low;
+
+ /* The loop counter and index J goes from -S1_SIZE to -1. This way
+ * the loop becomes faster. */
+ j = -s1_size;
+
+ /* Offset the base pointers to compensate for the negative indices. */
+ s1_ptr -= j;
+ res_ptr -= j;
+
+ cy_limb = 0;
+ do {
+ umul_ppmm( prod_high, prod_low, s1_ptr[j], s2_limb );
+ prod_low += cy_limb;
+ cy_limb = (prod_low < cy_limb?1:0) + prod_high;
+ res_ptr[j] = prod_low;
+ } while( ++j );
+
+ return cy_limb;
+}
+
diff --git a/mpi/generic/mpih-mul2.c b/mpi/generic/mpih-mul2.c
new file mode 100644
index 0000000..89ef6b9
--- /dev/null
+++ b/mpi/generic/mpih-mul2.c
@@ -0,0 +1,67 @@
+/* mpihelp-mul_2.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+
+mpi_limb_t
+mpihelp_addmul_1( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_size_t s1_size, mpi_limb_t s2_limb)
+{
+ mpi_limb_t cy_limb;
+ mpi_size_t j;
+ mpi_limb_t prod_high, prod_low;
+ mpi_limb_t x;
+
+ /* The loop counter and index J goes from -SIZE to -1. This way
+ * the loop becomes faster. */
+ j = -s1_size;
+ res_ptr -= j;
+ s1_ptr -= j;
+
+ cy_limb = 0;
+ do {
+ umul_ppmm( prod_high, prod_low, s1_ptr[j], s2_limb );
+
+ prod_low += cy_limb;
+ cy_limb = (prod_low < cy_limb?1:0) + prod_high;
+
+ x = res_ptr[j];
+ prod_low = x + prod_low;
+ cy_limb += prod_low < x?1:0;
+ res_ptr[j] = prod_low;
+ } while ( ++j );
+ return cy_limb;
+}
+
+
diff --git a/mpi/generic/mpih-mul3.c b/mpi/generic/mpih-mul3.c
new file mode 100644
index 0000000..ac473a0
--- /dev/null
+++ b/mpi/generic/mpih-mul3.c
@@ -0,0 +1,68 @@
+/* mpihelp-mul_3.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+
+mpi_limb_t
+mpihelp_submul_1( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_size_t s1_size, mpi_limb_t s2_limb)
+{
+ mpi_limb_t cy_limb;
+ mpi_size_t j;
+ mpi_limb_t prod_high, prod_low;
+ mpi_limb_t x;
+
+ /* The loop counter and index J goes from -SIZE to -1. This way
+ * the loop becomes faster. */
+ j = -s1_size;
+ res_ptr -= j;
+ s1_ptr -= j;
+
+ cy_limb = 0;
+ do {
+ umul_ppmm( prod_high, prod_low, s1_ptr[j], s2_limb);
+
+ prod_low += cy_limb;
+ cy_limb = (prod_low < cy_limb?1:0) + prod_high;
+
+ x = res_ptr[j];
+ prod_low = x - prod_low;
+ cy_limb += prod_low > x?1:0;
+ res_ptr[j] = prod_low;
+ } while( ++j );
+
+ return cy_limb;
+}
+
+
diff --git a/mpi/generic/mpih-rshift.c b/mpi/generic/mpih-rshift.c
new file mode 100644
index 0000000..7aefc59
--- /dev/null
+++ b/mpi/generic/mpih-rshift.c
@@ -0,0 +1,69 @@
+/* mpih-rshift.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1998, 1999,
+ * 2000, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GNUPG
+ *
+ * GNUPG 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GNUPG 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+
+
+/* Shift U (pointed to by UP and USIZE limbs long) CNT bits to the right
+ * and store the USIZE least significant limbs of the result at WP.
+ * The bits shifted out to the right are returned.
+ *
+ * Argument constraints:
+ * 1. 0 < CNT < BITS_PER_MP_LIMB
+ * 2. If the result is to be written over the input, WP must be <= UP.
+ */
+
+mpi_limb_t
+mpihelp_rshift( mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize, unsigned cnt)
+{
+ mpi_limb_t high_limb, low_limb;
+ unsigned sh_1, sh_2;
+ mpi_size_t i;
+ mpi_limb_t retval;
+
+ sh_1 = cnt;
+ wp -= 1;
+ sh_2 = BITS_PER_MPI_LIMB - sh_1;
+ high_limb = up[0];
+ retval = high_limb << sh_2;
+ low_limb = high_limb;
+ for( i=1; i < usize; i++) {
+ high_limb = up[i];
+ wp[i] = (low_limb >> sh_1) | (high_limb << sh_2);
+ low_limb = high_limb;
+ }
+ wp[i] = low_limb >> sh_1;
+
+ return retval;
+}
+
diff --git a/mpi/generic/mpih-sub1.c b/mpi/generic/mpih-sub1.c
new file mode 100644
index 0000000..2230457
--- /dev/null
+++ b/mpi/generic/mpih-sub1.c
@@ -0,0 +1,66 @@
+/* mpihelp-add_2.c - MPI helper functions
+ * Copyright (C) 1994, 1996, 1997, 1998, 2001 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ * The GNU MP Library itself is published under the LGPL;
+ * however I decided to publish this code under the plain GPL.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+mpi_limb_t
+mpihelp_sub_n( mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
+ mpi_ptr_t s2_ptr, mpi_size_t size)
+{
+ mpi_limb_t x, y, cy;
+ mpi_size_t j;
+
+ /* The loop counter and index J goes from -SIZE to -1. This way
+ the loop becomes faster. */
+ j = -size;
+
+ /* Offset the base pointers to compensate for the negative indices. */
+ s1_ptr -= j;
+ s2_ptr -= j;
+ res_ptr -= j;
+
+ cy = 0;
+ do {
+ y = s2_ptr[j];
+ x = s1_ptr[j];
+ y += cy; /* add previous carry to subtrahend */
+ cy = y < cy; /* get out carry from that addition */
+ y = x - y; /* main subtract */
+ cy += y > x; /* get out carry from the subtract, combine */
+ res_ptr[j] = y;
+ } while( ++j );
+
+ return cy;
+}
+
+
diff --git a/mpi/generic/udiv-w-sdiv.c b/mpi/generic/udiv-w-sdiv.c
new file mode 100644
index 0000000..de71011
--- /dev/null
+++ b/mpi/generic/udiv-w-sdiv.c
@@ -0,0 +1,134 @@
+/* mpihelp_udiv_w_sdiv -- implement udiv_qrnnd on machines with only signed
+ * division.
+ * Copyright (C) 1992, 1994, 1996, 1998 Free Software Foundation, Inc.
+ * Contributed by Peter L. Montgomery.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+ * USA.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+
+#if 0 /* not yet ported to MPI */
+
+mpi_limb_t
+mpihelp_udiv_w_sdiv( mpi_limp_t *rp,
+ mpi_limp_t *a1,
+ mpi_limp_t *a0,
+ mpi_limp_t *d )
+{
+ mp_limb_t q, r;
+ mp_limb_t c0, c1, b1;
+
+ if ((mpi_limb_signed_t) d >= 0)
+ {
+ if (a1 < d - a1 - (a0 >> (BITS_PER_MP_LIMB - 1)))
+ {
+ /* dividend, divisor, and quotient are nonnegative */
+ sdiv_qrnnd (q, r, a1, a0, d);
+ }
+ else
+ {
+ /* Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d */
+ sub_ddmmss (c1, c0, a1, a0, d >> 1, d << (BITS_PER_MP_LIMB - 1));
+ /* Divide (c1*2^32 + c0) by d */
+ sdiv_qrnnd (q, r, c1, c0, d);
+ /* Add 2^31 to quotient */
+ q += (mp_limb_t) 1 << (BITS_PER_MP_LIMB - 1);
+ }
+ }
+ else
+ {
+ b1 = d >> 1; /* d/2, between 2^30 and 2^31 - 1 */
+ c1 = a1 >> 1; /* A/2 */
+ c0 = (a1 << (BITS_PER_MP_LIMB - 1)) + (a0 >> 1);
+
+ if (a1 < b1) /* A < 2^32*b1, so A/2 < 2^31*b1 */
+ {
+ sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */
+
+ r = 2*r + (a0 & 1); /* Remainder from A/(2*b1) */
+ if ((d & 1) != 0)
+ {
+ if (r >= q)
+ r = r - q;
+ else if (q - r <= d)
+ {
+ r = r - q + d;
+ q--;
+ }
+ else
+ {
+ r = r - q + 2*d;
+ q -= 2;
+ }
+ }
+ }
+ else if (c1 < b1) /* So 2^31 <= (A/2)/b1 < 2^32 */
+ {
+ c1 = (b1 - 1) - c1;
+ c0 = ~c0; /* logical NOT */
+
+ sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */
+
+ q = ~q; /* (A/2)/b1 */
+ r = (b1 - 1) - r;
+
+ r = 2*r + (a0 & 1); /* A/(2*b1) */
+
+ if ((d & 1) != 0)
+ {
+ if (r >= q)
+ r = r - q;
+ else if (q - r <= d)
+ {
+ r = r - q + d;
+ q--;
+ }
+ else
+ {
+ r = r - q + 2*d;
+ q -= 2;
+ }
+ }
+ }
+ else /* Implies c1 = b1 */
+ { /* Hence a1 = d - 1 = 2*b1 - 1 */
+ if (a0 >= -d)
+ {
+ q = -1;
+ r = a0 + d;
+ }
+ else
+ {
+ q = -2;
+ r = a0 + 2*d;
+ }
+ }
+ }
+
+ *rp = r;
+ return q;
+}
+
+#endif
+