1/* ix87 specific frexp implementation for float. 2 Copyright (C) 1997, 2000 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, write to the Free 18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307 USA. */ 20 21#include <machine/asm.h> 22#include "bp-sym.h" 23#include "bp-asm.h" 24 25#ifdef __ELF__ 26 .section .rodata 27#else 28 .text 29#endif 30 31 .align ALIGNARG(4) 32 ASM_TYPE_DIRECTIVE(two25,@object) 33two25: .byte 0, 0, 0, 0x4c 34 ASM_SIZE_DIRECTIVE(two25) 35 36#ifdef PIC 37#define MO(op) op##@GOTOFF(%edx) 38#else 39#define MO(op) op 40#endif 41 42#define PARMS LINKAGE /* no space for saved regs */ 43#define VAL PARMS 44#define EXPP VAL+4 45 46 .text 47ENTRY (BP_SYM (__frexpf)) 48 ENTER 49 50 movl VAL(%esp), %eax 51 xorl %ecx, %ecx 52 movl %eax, %edx 53 andl $0x7fffffff, %eax 54 jz 1f 55 cmpl $0x7f800000, %eax 56 jae 1f 57 58 cmpl $0x00800000, %eax 59 jae 2f 60 61 flds VAL(%esp) 62#ifdef PIC 63 call 3f 643: popl %edx 65 addl $_GLOBAL_OFFSET_TABLE_+[.-3b], %edx 66#endif 67 fmuls MO(two25) 68 movl $-25, %ecx 69 fstps VAL(%esp) 70 fwait 71 movl VAL(%esp), %eax 72 movl %eax, %edx 73 andl $0x7fffffff, %eax 74 752: shrl $23, %eax 76 andl $0x807fffff, %edx 77 subl $126, %eax 78 orl $0x3f000000, %edx 79 addl %eax, %ecx 80 movl %edx, VAL(%esp) 81 82 /* Store %ecx in the variable pointed to by the second argument, 83 get the factor from the stack and return. */ 841: movl EXPP(%esp), %eax 85 CHECK_BOUNDS_BOTH_WIDE (%eax, EXPP(%esp), $4) 86 flds VAL(%esp) 87 movl %ecx, (%eax) 88 89 LEAVE 90 ret 91END (BP_SYM (__frexpf)) 92weak_alias (BP_SYM (__frexpf), BP_SYM (frexpf)) 93