linux_dsm_epyc7002/arch/mips/math-emu/dp_2008class.c
Markos Chandras 38db37ba06 MIPS: math-emu: Add support for the MIPS R6 CLASS FPU instruction
MIPS R6 introduced the following instruction:
Stores in fd a bit mask reflecting the floating-point class of the
floating point scalar value fs.

CLASS.fmt: FPR[fd] = class(FPR[fs])

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10959/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03 12:08:14 +02:00

56 lines
1.1 KiB
C

/*
* IEEE754 floating point arithmetic
* double precision: CLASS.f
* FPR[fd] = class(FPR[fs])
*
* MIPS floating point support
* Copyright (C) 2015 Imagination Technologies, Ltd.
* Author: Markos Chandras <markos.chandras@imgtec.com>
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; version 2 of the License.
*/
#include "ieee754dp.h"
int ieee754dp_2008class(union ieee754dp x)
{
COMPXDP;
EXPLODEXDP;
/*
* 10 bit mask as follows:
*
* bit0 = SNAN
* bit1 = QNAN
* bit2 = -INF
* bit3 = -NORM
* bit4 = -DNORM
* bit5 = -ZERO
* bit6 = INF
* bit7 = NORM
* bit8 = DNORM
* bit9 = ZERO
*/
switch(xc) {
case IEEE754_CLASS_SNAN:
return 0x01;
case IEEE754_CLASS_QNAN:
return 0x02;
case IEEE754_CLASS_INF:
return 0x04 << (xs ? 0 : 4);
case IEEE754_CLASS_NORM:
return 0x08 << (xs ? 0 : 4);
case IEEE754_CLASS_DNORM:
return 0x10 << (xs ? 0 : 4);
case IEEE754_CLASS_ZERO:
return 0x20 << (xs ? 0 : 4);
default:
pr_err("Unknown class: %d\n", xc);
return 0;
}
}