glibc/sysdeps/i386/fpu/s_frexpf.S
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2019-01-01 00:11:28 +00:00

82 lines
1.9 KiB
ArmAsm

/* ix87 specific frexp implementation for float.
Copyright (C) 1997-2019 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, see
<http://www.gnu.org/licenses/>. */
#include <machine/asm.h>
#include <libm-alias-float.h>
.section .rodata
.align ALIGNARG(4)
.type 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 4 /* no space for saved regs */
#define VAL PARMS
#define EXPP VAL+4
.text
ENTRY (__frexpf)
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
LOAD_PIC_REG (dx)
#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
flds VAL(%esp)
movl %ecx, (%eax)
ret
END (__frexpf)
libm_alias_float (__frexp, frexp)