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-rw-r--r--newlib/libm/common/s_round.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/newlib/libm/common/s_round.c b/newlib/libm/common/s_round.c
new file mode 100644
index 0000000..09f19de
--- /dev/null
+++ b/newlib/libm/common/s_round.c
@@ -0,0 +1,83 @@
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#include "fdlibm.h"
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+ double round(double x)
+#else
+ double round(x)
+ double x;
+#endif
+{
+ /* Most significant word, least significant word. */
+ __int32_t msw, exponent_less_1023;
+ __uint32_t lsw;
+
+ EXTRACT_WORDS(msw, lsw, x);
+
+ /* Extract exponent field. */
+ exponent_less_1023 = ((msw & 0x7ff00000) >> 20) - 1023;
+
+ if (exponent_less_1023 < 20)
+ {
+ if (exponent_less_1023 < 0)
+ {
+ msw &= 0x80000000;
+ if (exponent_less_1023 == -1)
+ /* Result is +1.0 or -1.0. */
+ msw |= (1023 << 20);
+ lsw = 0;
+ }
+ else
+ {
+ __uint32_t exponent_mask = 0x000fffff >> exponent_less_1023;
+ if ((msw & exponent_mask) == 0 && lsw == 0)
+ /* x in an integral value. */
+ return x;
+
+ msw += 0x00080000 >> exponent_less_1023;
+ msw &= ~exponent_mask;
+ lsw = 0;
+ }
+ }
+ else if (exponent_less_1023 > 51)
+ {
+ if (exponent_less_1023 == 1024)
+ /* x is NaN or infinite. */
+ return x + x;
+ else
+ return x;
+ }
+ else
+ {
+ __uint32_t exponent_mask = 0xffffffff >> (exponent_less_1023 - 20);
+ __uint32_t tmp;
+
+ if ((lsw & exponent_mask) == 0)
+ /* x is an integral value. */
+ return x;
+
+ tmp = lsw + (1 << (51 - exponent_less_1023));
+ if (tmp < lsw)
+ msw += 1;
+ lsw = tmp;
+
+ lsw &= ~exponent_mask;
+ }
+ INSERT_WORDS(x, msw, lsw);
+
+ return x;
+}
+
+#endif /* _DOUBLE_IS_32BITS */