diff options
Diffstat (limited to 'lib/libcompiler_rt/ppc/floatditf.c')
-rw-r--r-- | lib/libcompiler_rt/ppc/floatditf.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/lib/libcompiler_rt/ppc/floatditf.c b/lib/libcompiler_rt/ppc/floatditf.c new file mode 100644 index 00000000000..beabdd01742 --- /dev/null +++ b/lib/libcompiler_rt/ppc/floatditf.c @@ -0,0 +1,36 @@ +/* This file is distributed under the University of Illinois Open Source + * License. See LICENSE.TXT for details. + */ + +/* long double __floatditf(long long x); */ +/* This file implements the PowerPC long long -> long double conversion */ + +#include "DD.h" + +long double __floatditf(int64_t a) { + + static const double twop32 = 0x1.0p32; + static const double twop52 = 0x1.0p52; + + doublebits low = { .d = twop52 }; + low.x |= a & UINT64_C(0x00000000ffffffff); /* 0x1.0p52 + low 32 bits of a. */ + + const double high_addend = (double)((int32_t)(a >> 32))*twop32 - twop52; + + /* At this point, we have two double precision numbers + * high_addend and low.d, and we wish to return their sum + * as a canonicalized long double: + */ + + /* This implementation sets the inexact flag spuriously. + * This could be avoided, but at some substantial cost. + */ + + DD result; + + result.s.hi = high_addend + low.d; + result.s.lo = (high_addend - result.s.hi) + low.d; + + return result.ld; + +} |