diff options
Diffstat (limited to 'lib/fixunsdfdi.c')
-rw-r--r-- | lib/fixunsdfdi.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/lib/fixunsdfdi.c b/lib/fixunsdfdi.c new file mode 100644 index 000000000..f7e1041ad --- /dev/null +++ b/lib/fixunsdfdi.c @@ -0,0 +1,42 @@ +//===-- 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; +} |