diff options
| -rw-r--r-- | src/math/ilogb.c | 14 | ||||
| -rw-r--r-- | src/math/ilogbf.c | 14 | ||||
| -rw-r--r-- | src/math/ilogbl.c | 31 |
3 files changed, 43 insertions, 16 deletions
diff --git a/src/math/ilogb.c b/src/math/ilogb.c index 5a1819d8..64d40154 100644 --- a/src/math/ilogb.c +++ b/src/math/ilogb.c @@ -3,22 +3,24 @@ int ilogb(double x) { - union dshape u = {x}; - int e = u.bits>>52 & 0x7ff; + #pragma STDC FENV_ACCESS ON + union {double f; uint64_t i;} u = {x}; + uint64_t i = u.i; + int e = i>>52 & 0x7ff; if (!e) { - u.bits <<= 12; - if (u.bits == 0) { + i <<= 12; + if (i == 0) { FORCE_EVAL(0/0.0f); return FP_ILOGB0; } /* subnormal x */ - for (e = -0x3ff; u.bits < (uint64_t)1<<63; e--, u.bits<<=1); + for (e = -0x3ff; i>>63 == 0; e--, i<<=1); return e; } if (e == 0x7ff) { FORCE_EVAL(0/0.0f); - return u.bits<<12 ? FP_ILOGBNAN : INT_MAX; + return i<<12 ? FP_ILOGBNAN : INT_MAX; } return e - 0x3ff; } diff --git a/src/math/ilogbf.c b/src/math/ilogbf.c index 42cd62e2..e23ba209 100644 --- a/src/math/ilogbf.c +++ b/src/math/ilogbf.c @@ -3,22 +3,24 @@ int ilogbf(float x) { - union fshape u = {x}; - int e = u.bits>>23 & 0xff; + #pragma STDC FENV_ACCESS ON + union {float f; uint32_t i;} u = {x}; + uint32_t i = u.i; + int e = i>>23 & 0xff; if (!e) { - u.bits <<= 9; - if (u.bits == 0) { + i <<= 9; + if (i == 0) { FORCE_EVAL(0/0.0f); return FP_ILOGB0; } /* subnormal x */ - for (e = -0x7f; u.bits < (uint32_t)1<<31; e--, u.bits<<=1); + for (e = -0x7f; i>>31 == 0; e--, i<<=1); return e; } if (e == 0xff) { FORCE_EVAL(0/0.0f); - return u.bits<<9 ? FP_ILOGBNAN : INT_MAX; + return i<<9 ? FP_ILOGBNAN : INT_MAX; } return e - 0x7f; } diff --git a/src/math/ilogbl.c b/src/math/ilogbl.c index 7df6eb6c..7b1a9cf8 100644 --- a/src/math/ilogbl.c +++ b/src/math/ilogbl.c @@ -9,23 +9,46 @@ 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.i.m; int e = u.i.se & 0x7fff; if (!e) { if (m == 0) { - FORCE_EVAL(x/x); + 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) { FORCE_EVAL(0/0.0f); - /* in ld80 msb is set in inf */ - return m << 1 ? FP_ILOGBNAN : INT_MAX; + 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; } |