Initial import

1 files changed, 196 insertions, 0 deletions

diff --git a/arch/mips/math-emu/ieee754sp.c b/arch/mips/math-emu/ieee754sp.c
new file mode 100644
index 000000000..ca8e35e33
--- /dev/null
+++ b/arch/mips/math-emu/ieee754sp.c
@@ -0,0 +1,196 @@
+/* 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 <linux/compiler.h>
+
+#include "ieee754sp.h"
+
+int ieee754sp_class(union ieee754sp x)
+{
+	COMPXSP;
+	EXPLODEXSP;
+	return xc;
+}
+
+static inline int ieee754sp_isnan(union ieee754sp x)
+{
+	return ieee754_class_nan(ieee754sp_class(x));
+}
+
+static inline int ieee754sp_issnan(union ieee754sp x)
+{
+	assert(ieee754sp_isnan(x));
+	return SPMANT(x) & SP_MBIT(SP_FBITS - 1);
+}
+
+
+/*
+ * Raise the Invalid Operation IEEE 754 exception
+ * and convert the signaling NaN supplied to a quiet NaN.
+ */
+union ieee754sp __cold ieee754sp_nanxcpt(union ieee754sp r)
+{
+	assert(ieee754sp_issnan(r));
+
+	ieee754_setcx(IEEE754_INVALID_OPERATION);
+	return ieee754sp_indef();
+}
+
+static unsigned ieee754sp_get_rounding(int sn, unsigned xm)
+{
+	/* inexact must round of 3 bits
+	 */
+	if (xm & (SP_MBIT(3) - 1)) {
+		switch (ieee754_csr.rm) {
+		case FPU_CSR_RZ:
+			break;
+		case FPU_CSR_RN:
+			xm += 0x3 + ((xm >> 3) & 1);
+			/* xm += (xm&0x8)?0x4:0x3 */
+			break;
+		case FPU_CSR_RU:	/* toward +Infinity */
+			if (!sn)	/* ?? */
+				xm += 0x8;
+			break;
+		case FPU_CSR_RD:	/* toward -Infinity */
+			if (sn) /* ?? */
+				xm += 0x8;
+			break;
+		}
+	}
+	return xm;
+}
+
+
+/* generate a normal/denormal number with over,under handling
+ * sn is sign
+ * xe is an unbiased exponent
+ * xm is 3bit extended precision value.
+ */
+union ieee754sp ieee754sp_format(int sn, int xe, unsigned xm)
+{
+	assert(xm);		/* we don't gen exact zeros (probably should) */
+
+	assert((xm >> (SP_FBITS + 1 + 3)) == 0);	/* no execess */
+	assert(xm & (SP_HIDDEN_BIT << 3));
+
+	if (xe < SP_EMIN) {
+		/* strip lower bits */
+		int es = SP_EMIN - xe;
+
+		if (ieee754_csr.nod) {
+			ieee754_setcx(IEEE754_UNDERFLOW);
+			ieee754_setcx(IEEE754_INEXACT);
+
+			switch(ieee754_csr.rm) {
+			case FPU_CSR_RN:
+			case FPU_CSR_RZ:
+				return ieee754sp_zero(sn);
+			case FPU_CSR_RU:      /* toward +Infinity */
+				if (sn == 0)
+					return ieee754sp_min(0);
+				else
+					return ieee754sp_zero(1);
+			case FPU_CSR_RD:      /* toward -Infinity */
+				if (sn == 0)
+					return ieee754sp_zero(0);
+				else
+					return ieee754sp_min(1);
+			}
+		}
+
+		if (xe == SP_EMIN - 1 &&
+		    ieee754sp_get_rounding(sn, xm) >> (SP_FBITS + 1 + 3))
+		{
+			/* Not tiny after rounding */
+			ieee754_setcx(IEEE754_INEXACT);
+			xm = ieee754sp_get_rounding(sn, xm);
+			xm >>= 1;
+			/* Clear grs bits */
+			xm &= ~(SP_MBIT(3) - 1);
+			xe++;
+		} else {
+			/* sticky right shift es bits
+			 */
+			SPXSRSXn(es);
+			assert((xm & (SP_HIDDEN_BIT << 3)) == 0);
+			assert(xe == SP_EMIN);
+		}
+	}
+	if (xm & (SP_MBIT(3) - 1)) {
+		ieee754_setcx(IEEE754_INEXACT);
+		if ((xm & (SP_HIDDEN_BIT << 3)) == 0) {
+			ieee754_setcx(IEEE754_UNDERFLOW);
+		}
+
+		/* inexact must round of 3 bits
+		 */
+		xm = ieee754sp_get_rounding(sn, xm);
+		/* adjust exponent for rounding add overflowing
+		 */
+		if (xm >> (SP_FBITS + 1 + 3)) {
+			/* add causes mantissa overflow */
+			xm >>= 1;
+			xe++;
+		}
+	}
+	/* strip grs bits */
+	xm >>= 3;
+
+	assert((xm >> (SP_FBITS + 1)) == 0);	/* no execess */
+	assert(xe >= SP_EMIN);
+
+	if (xe > SP_EMAX) {
+		ieee754_setcx(IEEE754_OVERFLOW);
+		ieee754_setcx(IEEE754_INEXACT);
+		/* -O can be table indexed by (rm,sn) */
+		switch (ieee754_csr.rm) {
+		case FPU_CSR_RN:
+			return ieee754sp_inf(sn);
+		case FPU_CSR_RZ:
+			return ieee754sp_max(sn);
+		case FPU_CSR_RU:	/* toward +Infinity */
+			if (sn == 0)
+				return ieee754sp_inf(0);
+			else
+				return ieee754sp_max(1);
+		case FPU_CSR_RD:	/* toward -Infinity */
+			if (sn == 0)
+				return ieee754sp_max(0);
+			else
+				return ieee754sp_inf(1);
+		}
+	}
+	/* gen norm/denorm/zero */
+
+	if ((xm & SP_HIDDEN_BIT) == 0) {
+		/* we underflow (tiny/zero) */
+		assert(xe == SP_EMIN);
+		if (ieee754_csr.mx & IEEE754_UNDERFLOW)
+			ieee754_setcx(IEEE754_UNDERFLOW);
+		return buildsp(sn, SP_EMIN - 1 + SP_EBIAS, xm);
+	} else {
+		assert((xm >> (SP_FBITS + 1)) == 0);	/* no execess */
+		assert(xm & SP_HIDDEN_BIT);
+
+		return buildsp(sn, xe + SP_EBIAS, xm & ~SP_HIDDEN_BIT);
+	}
+}