X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Filogbl.c;h=7b1a9cf8d007ff16c1d6fe072916a5a8a226e3e3;hb=a2a328bd896fa909542b492601e3689119b95de0;hp=ed9ddcbc42582ac0fb2c0ab5923a0bccb6ccd050;hpb=b69f695acedd4ce2798ef9ea28d834ceccc789bd;p=musl diff --git a/src/math/ilogbl.c b/src/math/ilogbl.c index ed9ddcbc..7b1a9cf8 100644 --- a/src/math/ilogbl.c +++ b/src/math/ilogbl.c @@ -9,20 +9,47 @@ int ilogbl(long double x) #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 int ilogbl(long double x) { + #pragma STDC FENV_ACCESS ON union ldshape u = {x}; - uint64_t m = u.bits.m; - int e = u.bits.exp; + uint64_t m = u.i.m; + int e = u.i.se & 0x7fff; if (!e) { - if (m == 0) + if (m == 0) { + FORCE_EVAL(0/0.0f); return FP_ILOGB0; + } /* subnormal x */ - for (e = -0x3fff+1; m < (uint64_t)1<<63; e--, m<<=1); + for (e = -0x3fff+1; m>>63 == 0; e--, m<<=1); return e; } - if (e == 0x7fff) - /* in ld80 msb is set in inf */ - return m & (uint64_t)-1>>1 ? FP_ILOGBNAN : INT_MAX; + if (e == 0x7fff) { + FORCE_EVAL(0/0.0f); + return m<<1 ? FP_ILOGBNAN : INT_MAX; + } + return e - 0x3fff; +} +#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 +int ilogbl(long double x) +{ + #pragma STDC FENV_ACCESS ON + union ldshape u = {x}; + int e = u.i.se & 0x7fff; + + if (!e) { + if (x == 0) { + FORCE_EVAL(0/0.0f); + return FP_ILOGB0; + } + /* subnormal x */ + x *= 0x1p120; + return ilogbl(x) - 120; + } + if (e == 0x7fff) { + FORCE_EVAL(0/0.0f); + u.i.se = 0; + return u.f ? FP_ILOGBNAN : INT_MAX; + } return e - 0x3fff; } #endif