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-rw-r--r--kernel/arch/mips/math-emu/sp_fmax.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/kernel/arch/mips/math-emu/sp_fmax.c b/kernel/arch/mips/math-emu/sp_fmax.c
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index 000000000..4d000844e
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+++ b/kernel/arch/mips/math-emu/sp_fmax.c
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+/*
+ * IEEE754 floating point arithmetic
+ * single precision: MAX{,A}.f
+ * MAX : Scalar Floating-Point Maximum
+ * MAXA: Scalar Floating-Point argument with Maximum Absolute Value
+ *
+ * MAX.S : FPR[fd] = maxNum(FPR[fs],FPR[ft])
+ * MAXA.S: 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 "ieee754sp.h"
+
+union ieee754sp ieee754sp_fmax(union ieee754sp x, union ieee754sp y)
+{
+ COMPXSP;
+ COMPYSP;
+
+ EXPLODEXSP;
+ EXPLODEYSP;
+
+ FLUSHXSP;
+ FLUSHYSP;
+
+ 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 ieee754sp_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 ieee754sp_nanxcpt(x);
+
+ /* numbers are preferred to NaNs */
+ 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_QNAN):
+ 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 ? y : 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 ys ? x : y;
+
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
+ if (xs == ys)
+ return x;
+ return ieee754sp_zero(1);
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
+ SPDNORMX;
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
+ SPDNORMY;
+ break;
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
+ SPDNORMX;
+ }
+
+ /* Finally get to do some computation */
+
+ assert(xm & SP_HIDDEN_BIT);
+ assert(ym & SP_HIDDEN_BIT);
+
+ /* Compare signs */
+ if (xs > ys)
+ return y;
+ else if (xs < ys)
+ return x;
+
+ /* Compare exponent */
+ if (xe > ye)
+ return x;
+ else if (xe < ye)
+ return y;
+
+ /* Compare mantissa */
+ if (xm <= ym)
+ return y;
+ return x;
+}
+
+union ieee754sp ieee754sp_fmaxa(union ieee754sp x, union ieee754sp y)
+{
+ COMPXSP;
+ COMPYSP;
+
+ EXPLODEXSP;
+ EXPLODEYSP;
+
+ FLUSHXSP;
+ FLUSHYSP;
+
+ 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 ieee754sp_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 ieee754sp_nanxcpt(x);
+
+ /* numbers are preferred to NaNs */
+ 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_QNAN):
+ 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):
+ if (xs == ys)
+ return x;
+ return ieee754sp_zero(1);
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
+ SPDNORMX;
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
+ SPDNORMY;
+ break;
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
+ SPDNORMX;
+ }
+
+ /* Finally get to do some computation */
+
+ assert(xm & SP_HIDDEN_BIT);
+ assert(ym & SP_HIDDEN_BIT);
+
+ /* Compare exponent */
+ if (xe > ye)
+ return x;
+ else if (xe < ye)
+ return y;
+
+ /* Compare mantissa */
+ if (xm <= ym)
+ return y;
+ return x;
+}