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| author | Ulrich Drepper <drepper@gmail.com> | 2011-10-12 11:27:51 -0400 |
|---|---|---|
| committer | Ulrich Drepper <drepper@gmail.com> | 2011-10-12 11:27:51 -0400 |
| commit | 0ac5ae2335292908f39031b1ea9fe8edce433c0f (patch) | |
| tree | f9d26c8abc0de39d18d4c13e70f6022cdc6b461f /sysdeps/ieee754/ldbl-128ibm/e_acosl.c | |
| parent | a843a204a3e8a0dd53584dad3668771abaec84ac (diff) | |
| download | glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.zip glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.gz glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.bz2 | |
Optimize libm
libm is now somewhat integrated with gcc's -ffinite-math-only option
and lots of the wrapper functions have been optimized.
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/e_acosl.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/e_acosl.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/e_acosl.c b/sysdeps/ieee754/ldbl-128ibm/e_acosl.c index 8823fd6..1b37c92 100644 --- a/sysdeps/ieee754/ldbl-128ibm/e_acosl.c +++ b/sysdeps/ieee754/ldbl-128ibm/e_acosl.c @@ -283,11 +283,11 @@ __ieee754_acosl (x) s = __ieee754_sqrtl (z); /* Compute an extended precision square root from the Newton iteration s -> 0.5 * (s + z / s). - The change w from s to the improved value is + The change w from s to the improved value is w = 0.5 * (s + z / s) - s = (s^2 + z)/2s - s = (z - s^2)/2s. - Express s = f1 + f2 where f1 * f1 is exactly representable. + Express s = f1 + f2 where f1 * f1 is exactly representable. w = (z - s^2)/2s = (z - f1^2 - 2 f1 f2 - f2^2)/2s . - s + w has extended precision. */ + s + w has extended precision. */ u.value = s; u.parts32.w2 = 0; u.parts32.w3 = 0; @@ -326,3 +326,4 @@ __ieee754_acosl (x) return 2.0 * w; } } +strong_alias (__ieee754_acosl, __acosl_finite) |