diff options
Diffstat (limited to 'lib/builtins/fixunsxfsi.c')
-rw-r--r-- | lib/builtins/fixunsxfsi.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/lib/builtins/fixunsxfsi.c b/lib/builtins/fixunsxfsi.c new file mode 100644 index 000000000000..df0a18e2c1ab --- /dev/null +++ b/lib/builtins/fixunsxfsi.c @@ -0,0 +1,44 @@ +/* ===-- fixunsxfsi.c - Implement __fixunsxfsi -----------------------------=== + * + * 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 __fixunsxfsi for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#if !_ARCH_PPC + +#include "int_lib.h" + +/* Returns: convert a to a unsigned int, rounding toward zero. + * Negative values all become zero. + */ + +/* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes + * su_int is a 32 bit integral type + * value in long double is representable in su_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 + */ + +COMPILER_RT_ABI su_int +__fixunsxfsi(long double a) +{ + long_double_bits fb; + fb.f = a; + int e = (fb.u.high.s.low & 0x00007FFF) - 16383; + if (e < 0 || (fb.u.high.s.low & 0x00008000)) + return 0; + return fb.u.low.s.high >> (31 - e); +} + +#endif /* !_ARCH_PPC */ |