diff options
Diffstat (limited to 'lib/builtins/fixdfdi.c')
| -rw-r--r-- | lib/builtins/fixdfdi.c | 45 | 
1 files changed, 45 insertions, 0 deletions
diff --git a/lib/builtins/fixdfdi.c b/lib/builtins/fixdfdi.c new file mode 100644 index 000000000000..86f9f6ce8db3 --- /dev/null +++ b/lib/builtins/fixdfdi.c @@ -0,0 +1,45 @@ +/* ===-- fixdfdi.c - Implement __fixdfdi -----------------------------------=== + * + *                     The LLVM Compiler Infrastructure + * + * This file is dual licensed under the MIT and the University of Illinois Open + * Source Licenses. 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 */ + +ARM_EABI_FNALIAS(d2lz, fixdfdi) + +COMPILER_RT_ABI di_int +__fixdfdi(double a) +{ +    double_bits fb; +    fb.f = a; +    int e = ((fb.u.s.high & 0x7FF00000) >> 20) - 1023; +    if (e < 0) +        return 0; +    di_int s = (si_int)(fb.u.s.high & 0x80000000) >> 31; +    dwords 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 ^ s) - s; +}   | 
