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Diffstat (limited to 'lib/libc/i386/gen/modf.S')
| -rw-r--r-- | lib/libc/i386/gen/modf.S | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/lib/libc/i386/gen/modf.S b/lib/libc/i386/gen/modf.S new file mode 100644 index 0000000..8310a0a --- /dev/null +++ b/lib/libc/i386/gen/modf.S @@ -0,0 +1,84 @@ +/*- + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Sean Eric Fagan. + * + * 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. + * 4. 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) + .asciz "@(#)modf.s 5.5 (Berkeley) 3/18/91" +#endif /* LIBC_SCCS and not lint */ +#include <machine/asm.h> +__FBSDID("$FreeBSD$"); + +/* + * modf(value, iptr): return fractional part of value, and stores the + * integral part into iptr (a pointer to double). + * + * Written by Sean Eric Fagan (sef@kithrup.COM) + * Sun Mar 11 20:27:30 PST 1990 + */ + +/* With CHOP mode on, frndint behaves as TRUNC does. Useful. */ + +ENTRY(modf) + pushl %ebp + movl %esp,%ebp + /* Check for Inf/NaN */ + movl 12(%ebp),%eax + andl $0x7fffffff,%eax + cmpl $0x7ff00000,%eax + jae 1f + /* Finite value */ + subl $16,%esp + fnstcw -12(%ebp) + movw -12(%ebp),%dx + orw $3072,%dx + movw %dx,-16(%ebp) + fldcw -16(%ebp) + fldl 8(%ebp) + frndint + fstpl -8(%ebp) + fldcw -12(%ebp) + movl 16(%ebp),%eax + movl -8(%ebp),%edx + movl -4(%ebp),%ecx + movl %edx,(%eax) + movl %ecx,4(%eax) + fldl 8(%ebp) + fsubl -8(%ebp) + leave + ret + /* Inf/NaN handling */ +1: fldl 8(%ebp) + movl 16(%ebp),%edx + fstl (%edx) + fldz + fdivp /* return +/- 0 for +/- Inf, NaN for NaN */ + leave + ret |
