File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/mips/math-emu/sp_fdp.c b/arch/mips/math-emu/sp_fdp.c
new file mode 100644
index 0000000..3797148
--- /dev/null
+++ b/arch/mips/math-emu/sp_fdp.c
@@ -0,0 +1,82 @@
+/* IEEE754 floating point arithmetic
+ * single precision
+ */
+/*
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope 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.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA.
+ */
+
+#include "ieee754sp.h"
+#include "ieee754dp.h"
+
+static inline union ieee754sp ieee754sp_nan_fdp(int xs, u64 xm)
+{
+	return buildsp(xs, SP_EMAX + 1 + SP_EBIAS,
+		       xm >> (DP_FBITS - SP_FBITS));
+}
+
+union ieee754sp ieee754sp_fdp(union ieee754dp x)
+{
+	union ieee754sp y;
+	u32 rm;
+
+	COMPXDP;
+	COMPYSP;
+
+	EXPLODEXDP;
+
+	ieee754_clearcx();
+
+	FLUSHXDP;
+
+	switch (xc) {
+	case IEEE754_CLASS_SNAN:
+		return ieee754sp_nanxcpt(ieee754sp_nan_fdp(xs, xm));
+
+	case IEEE754_CLASS_QNAN:
+		y = ieee754sp_nan_fdp(xs, xm);
+		EXPLODEYSP;
+		if (!ieee754_class_nan(yc))
+			y = ieee754sp_indef();
+		return y;
+
+	case IEEE754_CLASS_INF:
+		return ieee754sp_inf(xs);
+
+	case IEEE754_CLASS_ZERO:
+		return ieee754sp_zero(xs);
+
+	case IEEE754_CLASS_DNORM:
+		/* can't possibly be sp representable */
+		ieee754_setcx(IEEE754_UNDERFLOW);
+		ieee754_setcx(IEEE754_INEXACT);
+		if ((ieee754_csr.rm == FPU_CSR_RU && !xs) ||
+				(ieee754_csr.rm == FPU_CSR_RD && xs))
+			return ieee754sp_mind(xs);
+		return ieee754sp_zero(xs);
+
+	case IEEE754_CLASS_NORM:
+		break;
+	}
+
+	/*
+	 * Convert from DP_FBITS to SP_FBITS+3 with sticky right shift.
+	 */
+	rm = (xm >> (DP_FBITS - (SP_FBITS + 3))) |
+	     ((xm << (64 - (DP_FBITS - (SP_FBITS + 3)))) != 0);
+
+	return ieee754sp_format(xs, xe, rm);
+}