/* ix87 specific frexp implementation for float. Copyright (C) 1997, 2000 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 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 #include "bp-sym.h" #include "bp-asm.h" #ifdef __ELF__ .section .rodata #else .text #endif .align ALIGNARG(4) ASM_TYPE_DIRECTIVE(two25,@object) two25: .byte 0, 0, 0, 0x4c ASM_SIZE_DIRECTIVE(two25) #ifdef PIC #define MO(op) op##@GOTOFF(%edx) #else #define MO(op) op #endif #define PARMS LINKAGE /* no space for saved regs */ #define VAL PARMS #define EXPP VAL+4 .text ENTRY (BP_SYM (__frexpf)) ENTER movl VAL(%esp), %eax xorl %ecx, %ecx movl %eax, %edx andl $0x7fffffff, %eax jz 1f cmpl $0x7f800000, %eax jae 1f cmpl $0x00800000, %eax jae 2f flds VAL(%esp) #ifdef PIC call 3f 3: popl %edx addl $_GLOBAL_OFFSET_TABLE_+[.-3b], %edx #endif fmuls MO(two25) movl $-25, %ecx fstps VAL(%esp) fwait movl VAL(%esp), %eax movl %eax, %edx andl $0x7fffffff, %eax 2: shrl $23, %eax andl $0x807fffff, %edx subl $126, %eax orl $0x3f000000, %edx addl %eax, %ecx movl %edx, VAL(%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) flds VAL(%esp) movl %ecx, (%eax) LEAVE ret END (BP_SYM (__frexpf)) weak_alias (BP_SYM (__frexpf), BP_SYM (frexpf))