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Diffstat (limited to 'lib/fixdfdi.c')
-rw-r--r-- | lib/fixdfdi.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/lib/fixdfdi.c b/lib/fixdfdi.c new file mode 100644 index 000000000..87368b7e5 --- /dev/null +++ b/lib/fixdfdi.c @@ -0,0 +1,41 @@ +//===-- fixdfdi.c - Implement __fixdfdi -----------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements __fixdfdi for the compiler_rt library. +// +//===----------------------------------------------------------------------===// + +#include "int_lib.h" + +// Returns: convert a to a signed long long, rounding toward zero. + +// Assumption: double is a IEEE 64 bit floating point type +// su_int is a 32 bit integral type +// value in double is representable in di_int (no range checking performed) + +// seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm + +di_int +__fixdfdi(double a) +{ + double_bits fb; + fb.f = a; + int e = ((fb.u.high & 0x7FF00000) >> 20) - 1023; + if (e < 0) + return 0; + di_int s = (si_int)(fb.u.high & 0x80000000) >> 31; + dwords 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 ^ s) - s; +} |