diff options
Diffstat (limited to 'libm/i387/s_remquo.S')
| -rw-r--r-- | libm/i387/s_remquo.S | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/libm/i387/s_remquo.S b/libm/i387/s_remquo.S new file mode 100644 index 0000000..f752839 --- /dev/null +++ b/libm/i387/s_remquo.S @@ -0,0 +1,62 @@ +/*- + * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG> + * All rights reserved. + * + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. + */ + +/* + * Based on public-domain remainder routine by J.T. Conklin <jtc@NetBSD.org>. + */ + +#include <machine/asm.h> +__FBSDID("$FreeBSD: src/lib/msun/i387/s_remquo.S,v 1.1 2005/03/25 04:40:44 das Exp $"); + +ENTRY(remquo) + fldl 12(%esp) + fldl 4(%esp) +1: fprem1 + fstsw %ax + sahf + jp 1b + fstp %st(1) +/* Extract the three low-order bits of the quotient from C0,C3,C1. */ + shrl $6,%eax + movl %eax,%ecx + andl $0x108,%eax + rorl $7,%eax + orl %eax,%ecx + roll $4,%eax + orl %ecx,%eax + andl $7,%eax +/* Negate the quotient bits if x*y<0. Avoid using an unpredictable branch. */ + movl 16(%esp),%ecx + xorl 8(%esp),%ecx + sarl $16,%ecx + sarl $16,%ecx + xorl %ecx,%eax + andl $1,%ecx + addl %ecx,%eax +/* Store the quotient and return. */ + movl 20(%esp),%ecx + movl %eax,(%ecx) + ret |