/* Copyright (C) 2011-2016 Free Software Foundation, Inc.
Contributed by Embecosm on behalf of Adapteva, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC 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 General Public License
for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
. */
#include "../epiphany-asm.h"
.section _fast_div_text,"a",@progbits;
.balign 8;
_fast_div_table:
.word 0x007fffff// mantissa mask
.word 0x40257ebb// hold constant a = 2.58586
.word 0x3f000000// hold constant 126 shifted to bits [30:23]
.word 0xc0ba2e88// hold constant b = -5.81818
.word 0x4087c1e8// hold constant c = 4.24242
.word 0x40000000// to hold constant 2 for Newton-Raphson iterations
.global SYM(__fast_recipsf2)
FUNC(__fast_recipsf2)
SYM(__fast_recipsf2):
//###################
//# input operands:
//###################
// Divisor
//R0
// Function address (used with negative offsets to read _fast_div_table)
//R1
/* Scratch registers: two single (TMP0/TMP5) and two pairs. */
#define P0L TMP1
#define P0H TMP2
#define P1L TMP3
#define P1H TMP4
//#########################################
//# Constants to be used in the algorithm
//#########################################
ldrd P0L , [ R1 , -3 ]
ldrd P1L , [ R1 , -2 ]
//#############################################################################
//# The Algorithm
//#
//# Operation: C=A/B
//# stage 1 - find the reciprocal 1/B according to the following scheme:
//# B = (2^E)*m (1