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| author | Rich Felker <dalias@aerifal.cx> | 2018-06-14 11:00:58 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2018-06-14 13:59:41 -0400 |
| commit | 18f02c42a2b5397e8541f4663eb6ca00c1a806dd (patch) | |
| tree | 88299f2477ca68b54ef6a5b5051bb56b79a51d9d /src/math | |
| parent | d5e55ba3320c30310ca1d8938925d5424a652422 (diff) | |
| download | musl-18f02c42a2b5397e8541f4663eb6ca00c1a806dd.tar.gz musl-18f02c42a2b5397e8541f4663eb6ca00c1a806dd.tar.bz2 musl-18f02c42a2b5397e8541f4663eb6ca00c1a806dd.tar.xz musl-18f02c42a2b5397e8541f4663eb6ca00c1a806dd.zip | |
add support for m68k 80-bit long double variant
since x86 and m68k are the only archs with 80-bit long double and each
has mandatory endianness, select the variant via endianness.
differences are minor: apparently just byte order and representation
of infinities. the m68k format is not well-documented anywhere I could
find, so if other differences are found they may require additional
changes later.
Diffstat (limited to 'src/math')
| -rw-r--r-- | src/math/__fpclassifyl.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/src/math/__fpclassifyl.c b/src/math/__fpclassifyl.c index 481c0b94..e41781b6 100644 --- a/src/math/__fpclassifyl.c +++ b/src/math/__fpclassifyl.c @@ -13,10 +13,18 @@ int __fpclassifyl(long double x) int msb = u.i.m>>63; if (!e && !msb) return u.i.m ? FP_SUBNORMAL : FP_ZERO; + if (e == 0x7fff) { + /* The x86 variant of 80-bit extended precision only admits + * one representation of each infinity, with the mantissa msb + * necessarily set. The version with it clear is invalid/nan. + * The m68k variant, however, allows either, and tooling uses + * the version with it clear. */ + if (__BYTE_ORDER == __LITTLE_ENDIAN && !msb) + return FP_NAN; + return u.i.m << 1 ? FP_NAN : FP_INFINITE; + } if (!msb) return FP_NAN; - if (e == 0x7fff) - return u.i.m << 1 ? FP_NAN : FP_INFINITE; return FP_NORMAL; } #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 |