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-rw-r--r--lib/fixunsxfti.c45
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diff --git a/lib/fixunsxfti.c b/lib/fixunsxfti.c
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+//===-- fixunsxfti.c - Implement __fixunsxfti -----------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __fixunsxfti for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#if __x86_64
+
+#include "int_lib.h"
+
+// Returns: convert a to a unsigned long long, rounding toward zero.
+// Negative values all become zero.
+
+// Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
+// tu_int is a 64 bit integral type
+// value in long double is representable in tu_int or is negative
+// (no range checking performed)
+
+// gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
+// 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
+
+tu_int
+__fixunsxfti(long double a)
+{
+ long_double_bits fb;
+ fb.f = a;
+ int e = (fb.u.high.low & 0x00007FFF) - 16383;
+ if (e < 0 || (fb.u.high.low & 0x00008000))
+ return 0;
+ tu_int r = fb.u.low.all;
+ if (e > 63)
+ r <<= (e - 63);
+ else
+ r >>= (63 - e);
+ return r;
+}
+
+#endif