lib: utils: Drop dependency on libgcc by importing part of FreeBSD's libquad

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@jrtc27.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Anup Patel <anup.patel@wdc.com>

1 files changed, 66 insertions, 0 deletions

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);
+}