| /* ix87 specific frexp implementation for double. |
| Copyright (C) 1997, 2000, 2005 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 Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. */ |
| |
| #include <machine/asm.h> |
| #include "bp-sym.h" |
| #include "bp-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 |
| |
| #define PARMS LINKAGE /* no space for saved regs */ |
| #define VAL0 PARMS |
| #define VAL1 VAL0+4 |
| #define EXPP VAL1+4 |
| |
| .text |
| ENTRY (BP_SYM (__frexp)) |
| ENTER |
| |
| movl VAL0(%esp), %ecx |
| movl VAL1(%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 VAL0(%esp) |
| #ifdef PIC |
| LOAD_PIC_REG (dx) |
| #endif |
| fmull MO(two54) |
| movl $-54, %ecx |
| fstpl VAL0(%esp) |
| fwait |
| movl VAL1(%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, VAL1(%esp) |
| |
| /* Store %ecx in the variable pointed to by the second argument, |
| get the factor from the stack and return. */ |
| 1: movl EXPP(%esp), %eax |
| CHECK_BOUNDS_BOTH_WIDE (%eax, EXPP(%esp), $4) |
| fldl VAL0(%esp) |
| movl %ecx, (%eax) |
| |
| LEAVE |
| ret |
| END (BP_SYM (__frexp)) |
| weak_alias (BP_SYM (__frexp), BP_SYM (frexp)) |
