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Diffstat (limited to 'contrib/compiler-rt/lib/fixdfdi.c')
-rw-r--r-- | contrib/compiler-rt/lib/fixdfdi.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/fixdfdi.c b/contrib/compiler-rt/lib/fixdfdi.c new file mode 100644 index 0000000..3d3116c --- /dev/null +++ b/contrib/compiler-rt/lib/fixdfdi.c @@ -0,0 +1,43 @@ +/* ===-- 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.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; +} |