Age | Commit message (Collapse) | Author | Lines | |
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2018-04-11 | fix incorrect results for catan with some inputs | Rich Felker | -13/+1 | |

the catan implementation from OpenBSD includes a FIXME-annotated "overflow" branch that produces a meaningless and incorrect large-magnitude result. it was reachable via three paths, corresponding to gotos removed by this commit, in order: 1. pure imaginary argument with imaginary component greater than 1 in magnitude. this case does not seem at all exceptional and is handled (at least with the quality currently expected from our complex math functions) by the existing non-exceptional code path. 2. arguments on the unit circle, including the pure-real argument 1.0. these are not exceptional except for ±i, which should produce results with infinite imaginary component and which lead to computation of atan2(±0,0) in the existing non-exceptional code path. such calls to atan2() however are well-defined by POSIX. 3. the specific argument +i. this route should be unreachable due to the above (2), but subtle rounding effects might have made it possible in rare cases. continuing on the non-exceptional code path in this case would lead to computing the (real) log of an infinite argument, then producing a NAN when multiplying it by I. for now, remove the exceptional code paths entirely. replace the multiplication by I with construction of a complex number using the CMPLX macro so that the NAN issue (3) prevented cannot arise. with these changes, catan should give reasonably correct results for real arguments, and should no longer give completely-wrong results for pure-imaginary arguments outside the interval (-i,+i). | ||||

2018-04-09 | fix wrong result in casin and many related complex functions | Rich Felker | -3/+6 | |

the factor of -i noted in the comment at the top of casin.c was omitted from the actual code, yielding a result rotated 90 degrees and propagating into errors in other functions defined in terms of casin. implement multiplication by -i as a rotation of the real and imaginary parts of the result, rather than by actual multiplication, since the latter cannot be optimized without knowledge that the operand is finite. here, the rotation is the actual intent, anyway. | ||||

2015-05-01 | complex: fix ctanh(+-0+i*nan) and ctanh(+-0+-i*inf) | Szabolcs Nagy | -2/+4 | |

These cases were incorrect in C11 as described by http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1886.htm | ||||

2012-11-13 | complex: add C11 CMPLX macros and replace cpack with them | Szabolcs Nagy | -138/+138 | |

2012-03-22 | add creal/cimag macros in complex.h (and use them in the functions defs) | Rich Felker | -12/+9 | |

2012-03-13 | first commit of the new libm! | Rich Felker | -0/+2024 | |

thanks to the hard work of Szabolcs Nagy (nsz), identifying the best (from correctness and license standpoint) implementations from freebsd and openbsd and cleaning them up! musl should now fully support c99 float and long double math functions, and has near-complete complex math support. tgmath should also work (fully on gcc-compatible compilers, and mostly on any c99 compiler). based largely on commit 0376d44a890fea261506f1fc63833e7a686dca19 from nsz's libm git repo, with some additions (dummy versions of a few missing long double complex functions, etc.) by me. various cleanups still need to be made, including re-adding (if they're correct) some asm functions that were dropped. |