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-rw-r--r--lib/fixunsdfdi.c42
1 files changed, 42 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.high & 0x7FF00000) >> 20) - 1023;
+ if (e < 0 || (fb.u.high & 0x80000000))
+ return 0;
+ udwords r;
+ r.high = (fb.u.high & 0x000FFFFF) | 0x00100000;
+ r.low = fb.u.low;
+ if (e > 52)
+ r.all <<= (e - 52);
+ else
+ r.all >>= (52 - e);
+ return r.all;
+}