[PATCH v5 6/6] Drop dependency on libgcc by importing part of FreeBSD's libquad

Anup Patel anup at brainfault.org
Sun Jul 11 08:46:08 PDT 2021


On Sun, Jul 11, 2021 at 7:58 AM Jessica Clarke <jrtc27 at jrtc27.com> wrote:
>
> We only need libgcc for 64-bit division on RV32. Whilst GCC toolchains
> bundle libgcc, Clang toolchains tend not to ship libclang_rt.builtins
> given every compiler is a cross-compiler for every target and so you
> would need a silly number of builds of it, with only the native library
> available; only vendor-provided Clang toolchains specifically for bare
> metal cross-compiling are likely to provide it.
>
> Thus, import part of FreeBSD's implementation of the division support
> functions needed and stop linking against libgcc.
>
> Signed-off-by: Jessica Clarke <jrtc27 at jrtc27.com>

I tried this patch with GCC linux toolchain and U-Boot SPL and it worked
fine for me. Other please try LLVM and bare-metal toolchain at your end
and if you see any issue then please send a fix patch.

Reviewed-by: Anup Patel <anup.patel at wdc.com>
Tested-by: Anup Patel <anup.patel at wdc.com>

Applied this patch to the riscv/opensbi repo.

@Bin Meng Can you also try RV32 U-Boot SPL ? I did not try that.

Regards,
Anup

> ---
>  Makefile                              |   2 +-
>  lib/utils/libquad/divdi3.c            |  64 ++++++
>  lib/utils/libquad/include/limits.h    |  12 ++
>  lib/utils/libquad/include/sys/cdefs.h |  12 ++
>  lib/utils/libquad/include/sys/types.h |  25 +++
>  lib/utils/libquad/moddi3.c            |  66 ++++++
>  lib/utils/libquad/objects.mk          |  14 ++
>  lib/utils/libquad/qdivrem.c           | 278 ++++++++++++++++++++++++++
>  lib/utils/libquad/quad.h              | 105 ++++++++++
>  lib/utils/libquad/udivdi3.c           |  52 +++++
>  lib/utils/libquad/umoddi3.c           |  54 +++++
>  11 files changed, 683 insertions(+), 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index 5c188d5..129b8ed 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -279,7 +279,7 @@ ASFLAGS             +=      $(firmware-asflags-y)
>  ARFLAGS                =       rcs
>
>  ELFFLAGS       +=      $(USE_LD_FLAG)
> -ELFFLAGS       +=      -Wl,--build-id=none -Wl,-N -static-libgcc -lgcc
> +ELFFLAGS       +=      -Wl,--build-id=none -Wl,-N
>  ELFFLAGS       +=      $(platform-ldflags-y)
>  ELFFLAGS       +=      $(firmware-ldflags-y)
>
> diff --git a/lib/utils/libquad/divdi3.c b/lib/utils/libquad/divdi3.c
> new file mode 100644
> index 0000000..c5b4a37
> --- /dev/null
> +++ b/lib/utils/libquad/divdi3.c
> @@ -0,0 +1,64 @@
> +/*-
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright (c) 1992, 1993
> + *     The Regents of the University of California.  All rights reserved.
> + *
> + * This software was developed by the Computer Systems Engineering group
> + * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
> + * contributed to Berkeley.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of the University nor the names of its contributors
> + *    may be used to endorse or promote products derived from this software
> + *    without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#if defined(LIBC_SCCS) && !defined(lint)
> +static char sccsid[] = "@(#)divdi3.c   8.1 (Berkeley) 6/4/93";
> +#endif /* LIBC_SCCS and not lint */
> +#include <sys/cdefs.h>
> +__FBSDID("$FreeBSD$");
> +
> +#include "quad.h"
> +
> +/*
> + * Divide two signed quads.
> + * ??? if -1/2 should produce -1 on this machine, this code is wrong
> + */
> +quad_t
> +__divdi3(quad_t a, quad_t b)
> +{
> +       u_quad_t ua, ub, uq;
> +       int neg;
> +
> +       if (a < 0)
> +               ua = -(u_quad_t)a, neg = 1;
> +       else
> +               ua = a, neg = 0;
> +       if (b < 0)
> +               ub = -(u_quad_t)b, neg ^= 1;
> +       else
> +               ub = b;
> +       uq = __qdivrem(ua, ub, (u_quad_t *)0);
> +       return (neg ? -uq : uq);
> +}
> diff --git a/lib/utils/libquad/include/limits.h b/lib/utils/libquad/include/limits.h
> new file mode 100644
> index 0000000..9c69d27
> --- /dev/null
> +++ b/lib/utils/libquad/include/limits.h
> @@ -0,0 +1,12 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 Jessica Clarke <jrtc27 at jrtc27.com>
> + */
> +
> +#ifndef __LIMITS_H__
> +#define __LIMITS_H__
> +
> +#define CHAR_BIT 8
> +
> +#endif
> diff --git a/lib/utils/libquad/include/sys/cdefs.h b/lib/utils/libquad/include/sys/cdefs.h
> new file mode 100644
> index 0000000..e8d6faa
> --- /dev/null
> +++ b/lib/utils/libquad/include/sys/cdefs.h
> @@ -0,0 +1,12 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 Jessica Clarke <jrtc27 at jrtc27.com>
> + */
> +
> +#ifndef __SYS_CDEFS_H__
> +#define __SYS_CDEFS_H__
> +
> +#define __FBSDID(s) struct __hack
> +
> +#endif
> diff --git a/lib/utils/libquad/include/sys/types.h b/lib/utils/libquad/include/sys/types.h
> new file mode 100644
> index 0000000..e372437
> --- /dev/null
> +++ b/lib/utils/libquad/include/sys/types.h
> @@ -0,0 +1,25 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 Jessica Clarke <jrtc27 at jrtc27.com>
> + */
> +
> +#ifndef __SYS_TYPES_H__
> +#define __SYS_TYPES_H__
> +
> +#include <sbi/sbi_types.h>
> +
> +typedef unsigned long u_long;
> +
> +typedef int64_t quad_t;
> +typedef uint64_t u_quad_t;
> +
> +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
> +#define _QUAD_LOWWORD 1
> +#define _QUAD_HIGHWORD 0
> +#else
> +#define _QUAD_LOWWORD 0
> +#define _QUAD_HIGHWORD 1
> +#endif
> +
> +#endif
> diff --git a/lib/utils/libquad/moddi3.c b/lib/utils/libquad/moddi3.c
> new file mode 100644
> index 0000000..fc13b4d
> --- /dev/null
> +++ b/lib/utils/libquad/moddi3.c
> @@ -0,0 +1,66 @@
> +/*-
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright (c) 1992, 1993
> + *     The Regents of the University of California.  All rights reserved.
> + *
> + * This software was developed by the Computer Systems Engineering group
> + * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
> + * contributed to Berkeley.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of the University nor the names of its contributors
> + *    may be used to endorse or promote products derived from this software
> + *    without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#if defined(LIBC_SCCS) && !defined(lint)
> +static char sccsid[] = "@(#)moddi3.c   8.1 (Berkeley) 6/4/93";
> +#endif /* LIBC_SCCS and not lint */
> +#include <sys/cdefs.h>
> +__FBSDID("$FreeBSD$");
> +
> +#include "quad.h"
> +
> +/*
> + * Return remainder after dividing two signed quads.
> + *
> + * XXX
> + * If -1/2 should produce -1 on this machine, this code is wrong.
> + */
> +quad_t
> +__moddi3(quad_t a, quad_t b)
> +{
> +       u_quad_t ua, ub, ur;
> +       int neg;
> +
> +       if (a < 0)
> +               ua = -(u_quad_t)a, neg = 1;
> +       else
> +               ua = a, neg = 0;
> +       if (b < 0)
> +               ub = -(u_quad_t)b;
> +       else
> +               ub = b;
> +       (void)__qdivrem(ua, ub, &ur);
> +       return (neg ? -ur : ur);
> +}
> diff --git a/lib/utils/libquad/objects.mk b/lib/utils/libquad/objects.mk
> new file mode 100644
> index 0000000..5e53cd0
> --- /dev/null
> +++ b/lib/utils/libquad/objects.mk
> @@ -0,0 +1,14 @@
> +#
> +# SPDX-License-Identifier: BSD-2-Clause
> +#
> +# Copyright (c) 2021 Jessica Clarke <jrtc27 at jrtc27.com>
> +#
> +
> +ifeq ($(PLATFORM_RISCV_XLEN),32)
> +libsbiutils-objs-y += libquad/divdi3.o
> +libsbiutils-objs-y += libquad/moddi3.o
> +libsbiutils-objs-y += libquad/qdivrem.o
> +libsbiutils-objs-y += libquad/udivdi3.o
> +libsbiutils-objs-y += libquad/umoddi3.o
> +libsbiutils-genflags-y += -I$(libsbiutils_dir)/libquad/include
> +endif
> diff --git a/lib/utils/libquad/qdivrem.c b/lib/utils/libquad/qdivrem.c
> new file mode 100644
> index 0000000..ea09e7f
> --- /dev/null
> +++ b/lib/utils/libquad/qdivrem.c
> @@ -0,0 +1,278 @@
> +/*-
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright (c) 1992, 1993
> + *     The Regents of the University of California.  All rights reserved.
> + *
> + * This software was developed by the Computer Systems Engineering group
> + * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
> + * contributed to Berkeley.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of the University nor the names of its contributors
> + *    may be used to endorse or promote products derived from this software
> + *    without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#if defined(LIBC_SCCS) && !defined(lint)
> +static char sccsid[] = "@(#)qdivrem.c  8.1 (Berkeley) 6/4/93";
> +#endif /* LIBC_SCCS and not lint */
> +#include <sys/cdefs.h>
> +__FBSDID("$FreeBSD$");
> +
> +/*
> + * Multiprecision divide.  This algorithm is from Knuth vol. 2 (2nd ed),
> + * section 4.3.1, pp. 257--259.
> + */
> +
> +#include "quad.h"
> +
> +#define        B       (1L << HALF_BITS)       /* digit base */
> +
> +/* Combine two `digits' to make a single two-digit number. */
> +#define        COMBINE(a, b) (((u_long)(a) << HALF_BITS) | (b))
> +
> +/* select a type for digits in base B: use unsigned short if they fit */
> +#if ULONG_MAX == 0xffffffff && USHRT_MAX >= 0xffff
> +typedef unsigned short digit;
> +#else
> +typedef u_long digit;
> +#endif
> +
> +/*
> + * Shift p[0]..p[len] left `sh' bits, ignoring any bits that
> + * `fall out' the left (there never will be any such anyway).
> + * We may assume len >= 0.  NOTE THAT THIS WRITES len+1 DIGITS.
> + */
> +static void
> +shl(digit *p, int len, int sh)
> +{
> +       int i;
> +
> +       for (i = 0; i < len; i++)
> +               p[i] = LHALF(p[i] << sh) | (p[i + 1] >> (HALF_BITS - sh));
> +       p[i] = LHALF(p[i] << sh);
> +}
> +
> +/*
> + * __qdivrem(u, v, rem) returns u/v and, optionally, sets *rem to u%v.
> + *
> + * We do this in base 2-sup-HALF_BITS, so that all intermediate products
> + * fit within u_long.  As a consequence, the maximum length dividend and
> + * divisor are 4 `digits' in this base (they are shorter if they have
> + * leading zeros).
> + */
> +u_quad_t
> +__qdivrem(u_quad_t uq, u_quad_t vq, u_quad_t *arq)
> +{
> +       union uu tmp;
> +       digit *u, *v, *q;
> +       digit v1, v2;
> +       u_long qhat, rhat, t;
> +       int m, n, d, j, i;
> +       digit uspace[5], vspace[5], qspace[5];
> +
> +       /*
> +        * Take care of special cases: divide by zero, and u < v.
> +        */
> +       if (vq == 0) {
> +               /* divide by zero. */
> +               static volatile const unsigned int zero = 0;
> +
> +               tmp.ul[H] = tmp.ul[L] = 1 / zero;
> +               if (arq)
> +                       *arq = uq;
> +               return (tmp.q);
> +       }
> +       if (uq < vq) {
> +               if (arq)
> +                       *arq = uq;
> +               return (0);
> +       }
> +       u = &uspace[0];
> +       v = &vspace[0];
> +       q = &qspace[0];
> +
> +       /*
> +        * Break dividend and divisor into digits in base B, then
> +        * count leading zeros to determine m and n.  When done, we
> +        * will have:
> +        *      u = (u[1]u[2]...u[m+n]) sub B
> +        *      v = (v[1]v[2]...v[n]) sub B
> +        *      v[1] != 0
> +        *      1 < n <= 4 (if n = 1, we use a different division algorithm)
> +        *      m >= 0 (otherwise u < v, which we already checked)
> +        *      m + n = 4
> +        * and thus
> +        *      m = 4 - n <= 2
> +        */
> +       tmp.uq = uq;
> +       u[0] = 0;
> +       u[1] = HHALF(tmp.ul[H]);
> +       u[2] = LHALF(tmp.ul[H]);
> +       u[3] = HHALF(tmp.ul[L]);
> +       u[4] = LHALF(tmp.ul[L]);
> +       tmp.uq = vq;
> +       v[1] = HHALF(tmp.ul[H]);
> +       v[2] = LHALF(tmp.ul[H]);
> +       v[3] = HHALF(tmp.ul[L]);
> +       v[4] = LHALF(tmp.ul[L]);
> +       for (n = 4; v[1] == 0; v++) {
> +               if (--n == 1) {
> +                       u_long rbj;     /* r*B+u[j] (not root boy jim) */
> +                       digit q1, q2, q3, q4;
> +
> +                       /*
> +                        * Change of plan, per exercise 16.
> +                        *      r = 0;
> +                        *      for j = 1..4:
> +                        *              q[j] = floor((r*B + u[j]) / v),
> +                        *              r = (r*B + u[j]) % v;
> +                        * We unroll this completely here.
> +                        */
> +                       t = v[2];       /* nonzero, by definition */
> +                       q1 = u[1] / t;
> +                       rbj = COMBINE(u[1] % t, u[2]);
> +                       q2 = rbj / t;
> +                       rbj = COMBINE(rbj % t, u[3]);
> +                       q3 = rbj / t;
> +                       rbj = COMBINE(rbj % t, u[4]);
> +                       q4 = rbj / t;
> +                       if (arq)
> +                               *arq = rbj % t;
> +                       tmp.ul[H] = COMBINE(q1, q2);
> +                       tmp.ul[L] = COMBINE(q3, q4);
> +                       return (tmp.q);
> +               }
> +       }
> +
> +       /*
> +        * By adjusting q once we determine m, we can guarantee that
> +        * there is a complete four-digit quotient at &qspace[1] when
> +        * we finally stop.
> +        */
> +       for (m = 4 - n; u[1] == 0; u++)
> +               m--;
> +       for (i = 4 - m; --i >= 0;)
> +               q[i] = 0;
> +       q += 4 - m;
> +
> +       /*
> +        * Here we run Program D, translated from MIX to C and acquiring
> +        * a few minor changes.
> +        *
> +        * D1: choose multiplier 1 << d to ensure v[1] >= B/2.
> +        */
> +       d = 0;
> +       for (t = v[1]; t < B / 2; t <<= 1)
> +               d++;
> +       if (d > 0) {
> +               shl(&u[0], m + n, d);           /* u <<= d */
> +               shl(&v[1], n - 1, d);           /* v <<= d */
> +       }
> +       /*
> +        * D2: j = 0.
> +        */
> +       j = 0;
> +       v1 = v[1];      /* for D3 -- note that v[1..n] are constant */
> +       v2 = v[2];      /* for D3 */
> +       do {
> +               digit uj0, uj1, uj2;
> +
> +               /*
> +                * D3: Calculate qhat (\^q, in TeX notation).
> +                * Let qhat = min((u[j]*B + u[j+1])/v[1], B-1), and
> +                * let rhat = (u[j]*B + u[j+1]) mod v[1].
> +                * While rhat < B and v[2]*qhat > rhat*B+u[j+2],
> +                * decrement qhat and increase rhat correspondingly.
> +                * Note that if rhat >= B, v[2]*qhat < rhat*B.
> +                */
> +               uj0 = u[j + 0]; /* for D3 only -- note that u[j+...] change */
> +               uj1 = u[j + 1]; /* for D3 only */
> +               uj2 = u[j + 2]; /* for D3 only */
> +               if (uj0 == v1) {
> +                       qhat = B;
> +                       rhat = uj1;
> +                       goto qhat_too_big;
> +               } else {
> +                       u_long n = COMBINE(uj0, uj1);
> +                       qhat = n / v1;
> +                       rhat = n % v1;
> +               }
> +               while (v2 * qhat > COMBINE(rhat, uj2)) {
> +       qhat_too_big:
> +                       qhat--;
> +                       if ((rhat += v1) >= B)
> +                               break;
> +               }
> +               /*
> +                * D4: Multiply and subtract.
> +                * The variable `t' holds any borrows across the loop.
> +                * We split this up so that we do not require v[0] = 0,
> +                * and to eliminate a final special case.
> +                */
> +               for (t = 0, i = n; i > 0; i--) {
> +                       t = u[i + j] - v[i] * qhat - t;
> +                       u[i + j] = LHALF(t);
> +                       t = (B - HHALF(t)) & (B - 1);
> +               }
> +               t = u[j] - t;
> +               u[j] = LHALF(t);
> +               /*
> +                * D5: test remainder.
> +                * There is a borrow if and only if HHALF(t) is nonzero;
> +                * in that (rare) case, qhat was too large (by exactly 1).
> +                * Fix it by adding v[1..n] to u[j..j+n].
> +                */
> +               if (HHALF(t)) {
> +                       qhat--;
> +                       for (t = 0, i = n; i > 0; i--) { /* D6: add back. */
> +                               t += u[i + j] + v[i];
> +                               u[i + j] = LHALF(t);
> +                               t = HHALF(t);
> +                       }
> +                       u[j] = LHALF(u[j] + t);
> +               }
> +               q[j] = qhat;
> +       } while (++j <= m);             /* D7: loop on j. */
> +
> +       /*
> +        * If caller wants the remainder, we have to calculate it as
> +        * u[m..m+n] >> d (this is at most n digits and thus fits in
> +        * u[m+1..m+n], but we may need more source digits).
> +        */
> +       if (arq) {
> +               if (d) {
> +                       for (i = m + n; i > m; --i)
> +                               u[i] = (u[i] >> d) |
> +                                   LHALF(u[i - 1] << (HALF_BITS - d));
> +                       u[i] = 0;
> +               }
> +               tmp.ul[H] = COMBINE(uspace[1], uspace[2]);
> +               tmp.ul[L] = COMBINE(uspace[3], uspace[4]);
> +               *arq = tmp.q;
> +       }
> +
> +       tmp.ul[H] = COMBINE(qspace[1], qspace[2]);
> +       tmp.ul[L] = COMBINE(qspace[3], qspace[4]);
> +       return (tmp.q);
> +}
> diff --git a/lib/utils/libquad/quad.h b/lib/utils/libquad/quad.h
> new file mode 100644
> index 0000000..a9f8447
> --- /dev/null
> +++ b/lib/utils/libquad/quad.h
> @@ -0,0 +1,105 @@
> +/*-
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright (c) 1992, 1993
> + *     The Regents of the University of California.  All rights reserved.
> + *
> + * This software was developed by the Computer Systems Engineering group
> + * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
> + * contributed to Berkeley.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of the University nor the names of its contributors
> + *    may be used to endorse or promote products derived from this software
> + *    without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + *
> + *     @(#)quad.h      8.1 (Berkeley) 6/4/93
> + * $FreeBSD$
> + */
> +
> +/*
> + * Quad arithmetic.
> + *
> + * This library makes the following assumptions:
> + *
> + *  - The type long long (aka quad_t) exists.
> + *
> + *  - A quad variable is exactly twice as long as `long'.
> + *
> + *  - The machine's arithmetic is two's complement.
> + *
> + * This library can provide 128-bit arithmetic on a machine with 128-bit
> + * quads and 64-bit longs, for instance, or 96-bit arithmetic on machines
> + * with 48-bit longs.
> + */
> +
> +#include <sys/types.h>
> +#include <limits.h>
> +
> +/*
> + * Depending on the desired operation, we view a `long long' (aka quad_t) in
> + * one or more of the following formats.
> + */
> +union uu {
> +       quad_t  q;              /* as a (signed) quad */
> +       quad_t  uq;             /* as an unsigned quad */
> +       long    sl[2];          /* as two signed longs */
> +       u_long  ul[2];          /* as two unsigned longs */
> +};
> +
> +/*
> + * Define high and low longwords.
> + */
> +#define        H               _QUAD_HIGHWORD
> +#define        L               _QUAD_LOWWORD
> +
> +/*
> + * Total number of bits in a quad_t and in the pieces that make it up.
> + * These are used for shifting, and also below for halfword extraction
> + * and assembly.
> + */
> +#define        QUAD_BITS       (sizeof(quad_t) * CHAR_BIT)
> +#define        LONG_BITS       (sizeof(long) * CHAR_BIT)
> +#define        HALF_BITS       (sizeof(long) * CHAR_BIT / 2)
> +
> +/*
> + * Extract high and low shortwords from longword, and move low shortword of
> + * longword to upper half of long, i.e., produce the upper longword of
> + * ((quad_t)(x) << (number_of_bits_in_long/2)).  (`x' must actually be u_long.)
> + *
> + * These are used in the multiply code, to split a longword into upper
> + * and lower halves, and to reassemble a product as a quad_t, shifted left
> + * (sizeof(long)*CHAR_BIT/2).
> + */
> +#define        HHALF(x)        ((x) >> HALF_BITS)
> +#define        LHALF(x)        ((x) & ((1L << HALF_BITS) - 1))
> +#define        LHUP(x)         ((x) << HALF_BITS)
> +
> +int            __cmpdi2(quad_t a, quad_t b);
> +quad_t         __divdi3(quad_t a, quad_t b);
> +quad_t         __moddi3(quad_t a, quad_t b);
> +u_quad_t       __qdivrem(u_quad_t u, u_quad_t v, u_quad_t *rem);
> +int            __ucmpdi2(u_quad_t a, u_quad_t b);
> +u_quad_t       __udivdi3(u_quad_t a, u_quad_t b);
> +u_quad_t       __umoddi3(u_quad_t a, u_quad_t b);
> +
> +typedef unsigned int   qshift_t;
> diff --git a/lib/utils/libquad/udivdi3.c b/lib/utils/libquad/udivdi3.c
> new file mode 100644
> index 0000000..0e6f27e
> --- /dev/null
> +++ b/lib/utils/libquad/udivdi3.c
> @@ -0,0 +1,52 @@
> +/*-
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright (c) 1992, 1993
> + *     The Regents of the University of California.  All rights reserved.
> + *
> + * This software was developed by the Computer Systems Engineering group
> + * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
> + * contributed to Berkeley.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of the University nor the names of its contributors
> + *    may be used to endorse or promote products derived from this software
> + *    without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#if defined(LIBC_SCCS) && !defined(lint)
> +static char sccsid[] = "@(#)udivdi3.c  8.1 (Berkeley) 6/4/93";
> +#endif /* LIBC_SCCS and not lint */
> +#include <sys/cdefs.h>
> +__FBSDID("$FreeBSD$");
> +
> +#include "quad.h"
> +
> +/*
> + * Divide two unsigned quads.
> + */
> +u_quad_t
> +__udivdi3(u_quad_t a, u_quad_t b)
> +{
> +
> +       return (__qdivrem(a, b, (u_quad_t *)0));
> +}
> diff --git a/lib/utils/libquad/umoddi3.c b/lib/utils/libquad/umoddi3.c
> new file mode 100644
> index 0000000..7f45134
> --- /dev/null
> +++ b/lib/utils/libquad/umoddi3.c
> @@ -0,0 +1,54 @@
> +/*-
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright (c) 1992, 1993
> + *     The Regents of the University of California.  All rights reserved.
> + *
> + * This software was developed by the Computer Systems Engineering group
> + * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
> + * contributed to Berkeley.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of the University nor the names of its contributors
> + *    may be used to endorse or promote products derived from this software
> + *    without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#if defined(LIBC_SCCS) && !defined(lint)
> +static char sccsid[] = "@(#)umoddi3.c  8.1 (Berkeley) 6/4/93";
> +#endif /* LIBC_SCCS and not lint */
> +#include <sys/cdefs.h>
> +__FBSDID("$FreeBSD$");
> +
> +#include "quad.h"
> +
> +/*
> + * Return remainder after dividing two unsigned quads.
> + */
> +u_quad_t
> +__umoddi3(u_quad_t a, u_quad_t b)
> +{
> +       u_quad_t r;
> +
> +       (void)__qdivrem(a, b, &r);
> +       return (r);
> +}
> --
> 2.31.0
>
>
> --
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