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-rw-r--r--arch/mips/math-emu/dp_flong.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_flong.c b/arch/mips/math-emu/dp_flong.c
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+++ b/arch/mips/math-emu/dp_flong.c
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+// 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"
+
+union ieee754dp ieee754dp_flong(s64 x)
+{
+ u64 xm;
+ int xe;
+ int xs;
+
+ ieee754_clearcx();
+
+ if (x == 0)
+ return ieee754dp_zero(0);
+ if (x == 1 || x == -1)
+ return ieee754dp_one(x < 0);
+ if (x == 10 || x == -10)
+ return ieee754dp_ten(x < 0);
+
+ xs = (x < 0);
+ if (xs) {
+ if (x == (1ULL << 63))
+ xm = (1ULL << 63); /* max neg can't be safely negated */
+ else
+ xm = -x;
+ } else {
+ xm = x;
+ }
+
+ /* normalize */
+ xe = DP_FBITS + 3;
+ if (xm >> (DP_FBITS + 1 + 3)) {
+ /* shunt out overflow bits */
+ while (xm >> (DP_FBITS + 1 + 3)) {
+ XDPSRSX1();
+ }
+ } else {
+ /* normalize in grs extended double precision */
+ while ((xm >> (DP_FBITS + 3)) == 0) {
+ xm <<= 1;
+ xe--;
+ }
+ }
+
+ return ieee754dp_format(xs, xe, xm);
+}