summaryrefslogtreecommitdiffstats
path: root/arch/mips/math-emu/sp_fmin.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/math-emu/sp_fmin.c')
-rw-r--r--arch/mips/math-emu/sp_fmin.c252
1 files changed, 252 insertions, 0 deletions
diff --git a/arch/mips/math-emu/sp_fmin.c b/arch/mips/math-emu/sp_fmin.c
new file mode 100644
index 000000000..ad2599d4a
--- /dev/null
+++ b/arch/mips/math-emu/sp_fmin.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * IEEE754 floating point arithmetic
+ * single precision: MIN{,A}.f
+ * MIN : Scalar Floating-Point Minimum
+ * MINA: Scalar Floating-Point argument with Minimum Absolute Value
+ *
+ * MIN.S : FPR[fd] = minNum(FPR[fs],FPR[ft])
+ * MINA.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>
+ */
+
+#include "ieee754sp.h"
+
+union ieee754sp ieee754sp_fmin(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);
+
+ /*
+ * 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)
+ */
+ 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):
+ return ieee754sp_zero(xs | ys);
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
+ SPDNORMX;
+ fallthrough;
+ 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 x;
+ else if (xs < ys)
+ return y;
+
+ /* 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;
+ }
+
+ /* 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 */
+ if (xm <= ym)
+ return y;
+ return x;
+}
+
+union ieee754sp ieee754sp_fmina(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);
+
+ /*
+ * 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)
+ */
+ 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_INF):
+ return ieee754sp_inf(xs | ys);
+
+ 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 y;
+
+ 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 x;
+
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
+ return ieee754sp_zero(xs | ys);
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
+ SPDNORMX;
+ fallthrough;
+ 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 y;
+ else if (xe < ye)
+ return x;
+
+ /* Compare mantissa */
+ if (xm < ym)
+ return x;
+ else if (xm > ym)
+ return y;
+ else if (xs == 1)
+ return x;
+ return y;
+}