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Diffstat (limited to 'contrib/compiler-rt/lib/floatdixf.c')
-rw-r--r-- | contrib/compiler-rt/lib/floatdixf.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/floatdixf.c b/contrib/compiler-rt/lib/floatdixf.c new file mode 100644 index 0000000..bfda367 --- /dev/null +++ b/contrib/compiler-rt/lib/floatdixf.c @@ -0,0 +1,46 @@ +/* ===-- floatdixf.c - Implement __floatdixf -------------------------------=== + * + * The LLVM Compiler Infrastructure + * + * This file is distributed under the University of Illinois Open Source + * License. See LICENSE.TXT for details. + * + * ===----------------------------------------------------------------------=== + * + * This file implements __floatdixf for the compiler_rt library. + * + * ===----------------------------------------------------------------------=== + */ + +#if !_ARCH_PPC + +#include "int_lib.h" + +/* Returns: convert a to a long double, rounding toward even. */ + +/* Assumption: long double is a IEEE 80 bit floating point type padded to 128 bits + * di_int is a 64 bit integral type + */ + +/* 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 + */ + +long double +__floatdixf(di_int a) +{ + if (a == 0) + return 0.0; + const unsigned N = sizeof(di_int) * CHAR_BIT; + const di_int s = a >> (N-1); + a = (a ^ s) - s; + int clz = __builtin_clzll(a); + int e = (N - 1) - clz ; /* exponent */ + long_double_bits fb; + fb.u.high.s.low = ((su_int)s & 0x00008000) | /* sign */ + (e + 16383); /* exponent */ + fb.u.low.all = a << clz; /* mantissa */ + return fb.f; +} + +#endif /* !_ARCH_PPC */ |