2015-08-13 14:56:35 +07:00
|
|
|
/*
|
|
|
|
* IEEE754 floating point arithmetic
|
|
|
|
* double precision: MIN{,A}.f
|
|
|
|
* MIN : Scalar Floating-Point Minimum
|
|
|
|
* MINA: Scalar Floating-Point argument with Minimum Absolute Value
|
|
|
|
*
|
|
|
|
* MIN.D : FPR[fd] = minNum(FPR[fs],FPR[ft])
|
|
|
|
* MINA.D: FPR[fd] = maxNumMag(FPR[fs],FPR[ft])
|
|
|
|
*
|
|
|
|
* 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"
|
|
|
|
|
|
|
|
union ieee754dp ieee754dp_fmin(union ieee754dp x, union ieee754dp y)
|
|
|
|
{
|
|
|
|
COMPXDP;
|
|
|
|
COMPYDP;
|
|
|
|
|
|
|
|
EXPLODEXDP;
|
|
|
|
EXPLODEYDP;
|
|
|
|
|
|
|
|
FLUSHXDP;
|
|
|
|
FLUSHYDP;
|
|
|
|
|
|
|
|
ieee754_clearcx();
|
|
|
|
|
|
|
|
switch (CLPAIR(xc, yc)) {
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
|
|
|
|
return ieee754dp_nanxcpt(y);
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
|
|
|
|
return ieee754dp_nanxcpt(x);
|
|
|
|
|
MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix quiet NaN propagation
Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S> fd,fs,ft, if both
inputs are quiet NaNs. The <MAX|MAXA|MIN|MINA>.<D|S> specifications
state that the returned value in such cases should be the quiet NaN
contained in register fs.
A relevant example:
MAX.S fd,fs,ft:
If fs contains qNaN1, and ft contains qNaN2, fd is going to contain
qNaN1 (without this patch, it used to contain qNaN2).
Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16880/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-07-27 23:08:48 +07:00
|
|
|
/*
|
|
|
|
* Quiet NaN handling
|
|
|
|
*/
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The case of both inputs quiet NaNs
|
|
|
|
*/
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
|
|
|
|
return x;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The cases of exactly one input quiet NaN (numbers
|
|
|
|
* are here preferred as returned values to NaNs)
|
|
|
|
*/
|
2015-08-13 14:56:35 +07:00
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
|
|
|
|
return x;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
|
|
|
|
return y;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Infinity and zero handling
|
|
|
|
*/
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
|
|
|
|
return xs ? x : y;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
|
|
|
|
return ys ? y : x;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
|
MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zero
Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S>, if both inputs
are zeros. The right behavior in such cases is stated in instruction
reference manual and is as follows:
fs ft MAX MIN MAXA MINA
---------------------------------------------
0 0 0 0 0 0
0 -0 0 -0 0 -0
-0 0 0 -0 0 -0
-0 -0 -0 -0 -0 -0
Prior to this patch, some of the above cases were yielding correct
results. However, for the sake of code consistency, all such cases
are rewritten in this patch.
A relevant example:
MAX.S fd,fs,ft:
If fs contains +0.0, and ft contains -0.0, fd is going to contain
+0.0 (without this patch, it used to contain -0.0).
Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16881/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-07-27 23:08:49 +07:00
|
|
|
return ieee754dp_zero(xs | ys);
|
2015-08-13 14:56:35 +07:00
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
|
|
|
|
DPDNORMX;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
|
|
|
|
DPDNORMY;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
|
|
|
|
DPDNORMX;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Finally get to do some computation */
|
|
|
|
|
|
|
|
assert(xm & DP_HIDDEN_BIT);
|
|
|
|
assert(ym & DP_HIDDEN_BIT);
|
|
|
|
|
|
|
|
/* Compare signs */
|
|
|
|
if (xs > ys)
|
|
|
|
return x;
|
|
|
|
else if (xs < ys)
|
|
|
|
return y;
|
|
|
|
|
2017-07-27 23:08:50 +07:00
|
|
|
/* Signs of inputs are the same, let's compare exponents */
|
|
|
|
if (xs == 0) {
|
|
|
|
/* Inputs are both positive */
|
|
|
|
if (xe > ye)
|
|
|
|
return y;
|
|
|
|
else if (xe < ye)
|
|
|
|
return x;
|
|
|
|
} else {
|
|
|
|
/* Inputs are both negative */
|
|
|
|
if (xe > ye)
|
|
|
|
return x;
|
|
|
|
else if (xe < ye)
|
|
|
|
return y;
|
|
|
|
}
|
2015-08-13 14:56:35 +07:00
|
|
|
|
2017-07-27 23:08:50 +07:00
|
|
|
/* Signs and exponents of inputs are equal, let's compare mantissas */
|
|
|
|
if (xs == 0) {
|
|
|
|
/* Inputs are both positive, with equal signs and exponents */
|
|
|
|
if (xm <= ym)
|
|
|
|
return x;
|
|
|
|
return y;
|
|
|
|
}
|
|
|
|
/* Inputs are both negative, with equal signs and exponents */
|
2015-08-13 14:56:35 +07:00
|
|
|
if (xm <= ym)
|
2017-07-27 23:08:50 +07:00
|
|
|
return y;
|
|
|
|
return x;
|
2015-08-13 14:56:35 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
union ieee754dp ieee754dp_fmina(union ieee754dp x, union ieee754dp y)
|
|
|
|
{
|
|
|
|
COMPXDP;
|
|
|
|
COMPYDP;
|
|
|
|
|
|
|
|
EXPLODEXDP;
|
|
|
|
EXPLODEYDP;
|
|
|
|
|
|
|
|
FLUSHXDP;
|
|
|
|
FLUSHYDP;
|
|
|
|
|
|
|
|
ieee754_clearcx();
|
|
|
|
|
|
|
|
switch (CLPAIR(xc, yc)) {
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
|
|
|
|
return ieee754dp_nanxcpt(y);
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
|
|
|
|
return ieee754dp_nanxcpt(x);
|
|
|
|
|
MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix quiet NaN propagation
Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S> fd,fs,ft, if both
inputs are quiet NaNs. The <MAX|MAXA|MIN|MINA>.<D|S> specifications
state that the returned value in such cases should be the quiet NaN
contained in register fs.
A relevant example:
MAX.S fd,fs,ft:
If fs contains qNaN1, and ft contains qNaN2, fd is going to contain
qNaN1 (without this patch, it used to contain qNaN2).
Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16880/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-07-27 23:08:48 +07:00
|
|
|
/*
|
|
|
|
* Quiet NaN handling
|
|
|
|
*/
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The case of both inputs quiet NaNs
|
|
|
|
*/
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
|
|
|
|
return x;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* The cases of exactly one input quiet NaN (numbers
|
|
|
|
* are here preferred as returned values to NaNs)
|
|
|
|
*/
|
2015-08-13 14:56:35 +07:00
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
|
|
|
|
return x;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
|
|
|
|
return y;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Infinity and zero handling
|
|
|
|
*/
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
|
|
|
|
return x;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
|
|
|
|
return y;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
|
MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix cases of both inputs zero
Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S>, if both inputs
are zeros. The right behavior in such cases is stated in instruction
reference manual and is as follows:
fs ft MAX MIN MAXA MINA
---------------------------------------------
0 0 0 0 0 0
0 -0 0 -0 0 -0
-0 0 0 -0 0 -0
-0 -0 -0 -0 -0 -0
Prior to this patch, some of the above cases were yielding correct
results. However, for the sake of code consistency, all such cases
are rewritten in this patch.
A relevant example:
MAX.S fd,fs,ft:
If fs contains +0.0, and ft contains -0.0, fd is going to contain
+0.0 (without this patch, it used to contain -0.0).
Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16881/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-07-27 23:08:49 +07:00
|
|
|
return ieee754dp_zero(xs | ys);
|
2015-08-13 14:56:35 +07:00
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
|
|
|
|
DPDNORMX;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
|
|
|
|
DPDNORMY;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
|
|
|
|
DPDNORMX;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Finally get to do some computation */
|
|
|
|
|
|
|
|
assert(xm & DP_HIDDEN_BIT);
|
|
|
|
assert(ym & DP_HIDDEN_BIT);
|
|
|
|
|
|
|
|
/* Compare exponent */
|
|
|
|
if (xe > ye)
|
|
|
|
return y;
|
|
|
|
else if (xe < ye)
|
|
|
|
return x;
|
|
|
|
|
|
|
|
/* Compare mantissa */
|
2017-07-27 23:08:51 +07:00
|
|
|
if (xm < ym)
|
|
|
|
return x;
|
|
|
|
else if (xm > ym)
|
|
|
|
return y;
|
|
|
|
else if (xs == 1)
|
2015-08-13 14:56:35 +07:00
|
|
|
return x;
|
|
|
|
return y;
|
|
|
|
}
|