1/* ix87 specific frexp implementation for double. 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(two54,@object) 33two54: .byte 0, 0, 0, 0, 0, 0, 0x50, 0x43 34 ASM_SIZE_DIRECTIVE(two54) 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 VAL0 PARMS 44#define VAL1 VAL0+4 45#define EXPP VAL1+4 46 47 .text 48ENTRY (BP_SYM (__frexp)) 49 ENTER 50 51 movl VAL0(%esp), %ecx 52 movl VAL1(%esp), %eax 53 movl %eax, %edx 54 andl $0x7fffffff, %eax 55 orl %eax, %ecx 56 jz 1f 57 xorl %ecx, %ecx 58 cmpl $0x7ff00000, %eax 59 jae 1f 60 61 cmpl $0x00100000, %eax 62 jae 2f 63 64 fldl VAL0(%esp) 65#ifdef PIC 66 call 3f 673: popl %edx 68 addl $_GLOBAL_OFFSET_TABLE_+[.-3b], %edx 69#endif 70 fmull MO(two54) 71 movl $-54, %ecx 72 fstpl VAL0(%esp) 73 fwait 74 movl VAL1(%esp), %eax 75 movl %eax, %edx 76 andl $0x7fffffff, %eax 77 782: shrl $20, %eax 79 andl $0x800fffff, %edx 80 subl $1022, %eax 81 orl $0x3fe00000, %edx 82 addl %eax, %ecx 83 movl %edx, VAL1(%esp) 84 85 /* Store %ecx in the variable pointed to by the second argument, 86 get the factor from the stack and return. */ 871: movl EXPP(%esp), %eax 88 CHECK_BOUNDS_BOTH_WIDE (%eax, EXPP(%esp), $4) 89 fldl VAL0(%esp) 90 movl %ecx, (%eax) 91 92 LEAVE 93 ret 94END (BP_SYM (__frexp)) 95weak_alias (BP_SYM (__frexp), BP_SYM (frexp)) 96