diff options
Diffstat (limited to 'sysdeps/libm-i387/s_frexp.S')
| -rw-r--r-- | sysdeps/libm-i387/s_frexp.S | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/sysdeps/libm-i387/s_frexp.S b/sysdeps/libm-i387/s_frexp.S new file mode 100644 index 0000000000..6a05f26720 --- /dev/null +++ b/sysdeps/libm-i387/s_frexp.S @@ -0,0 +1,82 @@ +/* ix87 specific frexp implementation for double. + Copyright (C) 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include <machine/asm.h> + +#ifdef __ELF__ + .section .rodata +#else + .text +#endif + + .align ALIGNARG(4) + ASM_TYPE_DIRECTIVE(two54,@object) +two54: .byte 0, 0, 0, 0, 0, 0, 0x50, 0x43 + ASM_SIZE_DIRECTIVE(two54) + +#ifdef PIC +#define MO(op) op##@GOTOFF(%edx) +#else +#define MO(op) op +#endif + + .text +ENTRY(__frexp) + movl 4(%esp), %ecx + movl 8(%esp), %eax + movl %eax, %edx + andl $0x7fffffff, %eax + orl %eax, %ecx + jz 1f + xorl %ecx, %ecx + cmpl $0x7ff00000, %eax + jae 1f + + cmpl $0x00100000, %eax + jae 2f + + fldl 4(%esp) +#ifdef PIC + call 3f +3: popl %edx + addl $_GLOBAL_OFFSET_TABLE_+[.-3b], %edx +#endif + fmull MO(two54) + movl $-54, %ecx + fstpl 4(%esp) + movl 8(%esp), %eax + movl %eax, %edx + andl $0x7fffffff, %eax + +2: shrl $20, %eax + andl $0x800fffff, %edx + subl $1022, %eax + orl $0x3fe00000, %edx + addl %eax, %ecx + movl %edx, 8(%esp) + + /* Store %ecx in the variable pointed to by the second argument, + get the factor from the stack and return. */ +1: movl 12(%esp), %eax + fldl 4(%esp) + movl %ecx, (%eax) + ret +END(__frexp) +weak_alias (__frexp, frexp) |