glibc/sysdeps/i386/fpu/s_frexpl.S

93 lines
2.1 KiB
ArmAsm

/* ix87 specific frexp implementation for long double.
Copyright (C) 1997-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#include <libm-alias-ldouble.h>
#include <machine/asm.h>
.section .rodata
.align ALIGNARG(4)
.type two64,@object
two64: .byte 0, 0, 0, 0, 0, 0, 0xf0, 0x43
ASM_SIZE_DIRECTIVE(two64)
#ifdef PIC
#define MO(op) op##@GOTOFF(%edx)
#else
#define MO(op) op
#endif
#define PARMS 4 /* no space for saved regs */
#define VAL0 PARMS
#define VAL1 VAL0+4
#define VAL2 VAL1+4
#define EXPP VAL2+4
.text
ENTRY (__frexpl)
movl VAL0(%esp), %ecx
movl VAL2(%esp), %eax
orl VAL1(%esp), %ecx
movl %eax, %edx
andl $0x7fff, %eax
orl %eax, %ecx
jz 1f
xorl %ecx, %ecx
cmpl $0x7fff, %eax
je 3f
cmpl $0, %eax
jne 2f
fldt VAL0(%esp)
#ifdef PIC
LOAD_PIC_REG (dx)
#endif
fmull MO(two64) /* It's not necessary to use a 80bit factor */
movl $-64, %ecx
fstpt VAL0(%esp)
fwait
movl VAL2(%esp), %eax
movl %eax, %edx
andl $0x7fff, %eax
2: andl $0x8000, %edx
subl $16382, %eax
orl $0x3ffe, %edx
addl %eax, %ecx
movl %edx, VAL2(%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
fldt VAL0(%esp)
movl %ecx, (%eax)
ret
/* Infinity or NaN; ensure signaling NaNs are quieted. */
3: movl EXPP(%esp), %eax
fldt VAL0(%esp)
fadd %st
movl %ecx, (%eax)
ret
END (__frexpl)
libm_alias_ldouble (__frexp, frexp)