1 files changed, 100 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_tlong.c b/arch/mips/math-emu/dp_tlong.c
new file mode 100644
index 000000000..c61ef02d4
--- /dev/null
+++ b/arch/mips/math-emu/dp_tlong.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* IEEE754 floating point arithmetic
+ * double precision: common utilities
+ */
+/*
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ */
+
+#include "ieee754dp.h"
+
+s64 ieee754dp_tlong(union ieee754dp x)
+{
+	u64 residue;
+	int round;
+	int sticky;
+	int odd;
+
+	COMPXDP;
+
+	ieee754_clearcx();
+
+	EXPLODEXDP;
+	FLUSHXDP;
+
+	switch (xc) {
+	case IEEE754_CLASS_SNAN:
+	case IEEE754_CLASS_QNAN:
+		ieee754_setcx(IEEE754_INVALID_OPERATION);
+		return ieee754di_indef();
+
+	case IEEE754_CLASS_INF:
+		ieee754_setcx(IEEE754_INVALID_OPERATION);
+		return ieee754di_overflow(xs);
+
+	case IEEE754_CLASS_ZERO:
+		return 0;
+
+	case IEEE754_CLASS_DNORM:
+	case IEEE754_CLASS_NORM:
+		break;
+	}
+	if (xe >= 63) {
+		/* look for valid corner case */
+		if (xe == 63 && xs && xm == DP_HIDDEN_BIT)
+			return -0x8000000000000000LL;
+		/* Set invalid. We will only use overflow for floating
+		   point overflow */
+		ieee754_setcx(IEEE754_INVALID_OPERATION);
+		return ieee754di_overflow(xs);
+	}
+	/* oh gawd */
+	if (xe > DP_FBITS) {
+		xm <<= xe - DP_FBITS;
+	} else if (xe < DP_FBITS) {
+		if (xe < -1) {
+			residue = xm;
+			round = 0;
+			sticky = residue != 0;
+			xm = 0;
+		} else {
+			/* Shifting a u64 64 times does not work,
+			* so we do it in two steps. Be aware that xe
+			* may be -1 */
+			residue = xm << (xe + 1);
+			residue <<= 63 - DP_FBITS;
+			round = (residue >> 63) != 0;
+			sticky = (residue << 1) != 0;
+			xm >>= DP_FBITS - xe;
+		}
+		odd = (xm & 0x1) != 0x0;
+		switch (ieee754_csr.rm) {
+		case FPU_CSR_RN:
+			if (round && (sticky || odd))
+				xm++;
+			break;
+		case FPU_CSR_RZ:
+			break;
+		case FPU_CSR_RU:	/* toward +Infinity */
+			if ((round || sticky) && !xs)
+				xm++;
+			break;
+		case FPU_CSR_RD:	/* toward -Infinity */
+			if ((round || sticky) && xs)
+				xm++;
+			break;
+		}
+		if ((xm >> 63) != 0) {
+			/* This can happen after rounding */
+			ieee754_setcx(IEEE754_INVALID_OPERATION);
+			return ieee754di_overflow(xs);
+		}
+		if (round || sticky)
+			ieee754_setcx(IEEE754_INEXACT);
+	}
+	if (xs)
+		return -xm;
+	else
+		return xm;
+}