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-rw-r--r--lib/fixunsdfdi.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/lib/fixunsdfdi.c b/lib/fixunsdfdi.c
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+/* ===-- fixunsdfdi.c - Implement __fixunsdfdi -----------------------------===
+ *
+ * The LLVM Compiler Infrastructure
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __fixunsdfdi for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+/* Returns: convert a to a unsigned long long, rounding toward zero.
+ * Negative values all become zero.
+ */
+
+/* Assumption: double is a IEEE 64 bit floating point type
+ * du_int is a 64 bit integral type
+ * value in double is representable in du_int or is negative
+ * (no range checking performed)
+ */
+
+/* seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm */
+
+du_int
+__fixunsdfdi(double a)
+{
+ double_bits fb;
+ fb.f = a;
+ int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023;
+ if (e < 0 || (fb.u.s.high & 0x80000000))
+ return 0;
+ udwords r;
+ r.s.high = (fb.u.s.high & 0x000FFFFF) | 0x00100000;
+ r.s.low = fb.u.s.low;
+ if (e > 52)
+ r.all <<= (e - 52);
+ else
+ r.all >>= (52 - e);
+ return r.all;
+}