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Diffstat (limited to 'contrib/compiler-rt/lib/builtins/fixxfdi.c')
-rw-r--r-- | contrib/compiler-rt/lib/builtins/fixxfdi.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/builtins/fixxfdi.c b/contrib/compiler-rt/lib/builtins/fixxfdi.c new file mode 100644 index 000000000000..011787f9e4b4 --- /dev/null +++ b/contrib/compiler-rt/lib/builtins/fixxfdi.c @@ -0,0 +1,48 @@ +/* ===-- fixxfdi.c - Implement __fixxfdi -----------------------------------=== + * + * 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 __fixxfdi for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#if !_ARCH_PPC + +#include "int_lib.h" + +/* Returns: convert a to a signed long long, rounding toward zero. */ + +/* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes + * di_int is a 64 bit integral type + * value in long double is representable in di_int (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 di_int +__fixxfdi(long double a) +{ + const di_int di_max = (di_int)((~(du_int)0) / 2); + const di_int di_min = -di_max - 1; + long_double_bits fb; + fb.f = a; + int e = (fb.u.high.s.low & 0x00007FFF) - 16383; + if (e < 0) + return 0; + if ((unsigned)e >= sizeof(di_int) * CHAR_BIT) + return a > 0 ? di_max : di_min; + di_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15); + di_int r = fb.u.low.all; + r = (du_int)r >> (63 - e); + return (r ^ s) - s; +} + +#endif /* !_ARCH_PPC */ |