[PATCH 2/2] Drop dependency on libgcc by importing part of FreeBSD's libquad
Xiang W
wxjstz at 126.com
Thu Jul 8 02:02:02 PDT 2021
在 2021-07-03星期六的 18:56 +0100，Jessica Clarke写道：
> 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>
> ---
> 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 40bcab6..bc4429a 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -259,7 +259,7 @@ ASFLAGS += $(firmware-asflags-y)
>
> ARFLAGS = rcs
>
> -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);
Is this function used to compare two 64-bit variables? I tested the
comparison operation with gcc/clang, and the comparison operation does
not call any functions. And this function is not defined, this
declaration can be removed.
> +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);
Here the same as above.
Regards,
Xiang W
> +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
>
>
More information about the opensbi
mailing list