diff options
author | Nicholas Noll <nbnoll@eml.cc> | 2021-12-05 16:16:21 -0800 |
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committer | Nicholas Noll <nbnoll@eml.cc> | 2021-12-05 16:16:21 -0800 |
commit | 07e77936d535e58b0aeb4f2a11400c1050556739 (patch) | |
tree | fb50fad6436ecbc159505bee73a92cd289b99a07 /src/base/math/fmod.c | |
parent | b48327d357e0818d1a6ae2a064cfa7d1567e1242 (diff) |
Feat: added math library
Used Plan9's libc as starting point. This cleans up dangling references
due to loss of libc.
Diffstat (limited to 'src/base/math/fmod.c')
-rw-r--r-- | src/base/math/fmod.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/src/base/math/fmod.c b/src/base/math/fmod.c new file mode 100644 index 0000000..d724a8c --- /dev/null +++ b/src/base/math/fmod.c @@ -0,0 +1,31 @@ +#include <u.h> +#include <base.h> + +/* + * floating-point mod function without infinity or NaN checking + */ +double +math·fmod(double x, double y) +{ + int sign, yexp, rexp; + double r, yfr, rfr; + + if (y == 0) + return x; + if (y < 0) + y = -y; + yfr = math·frexp(y, &yexp); + sign = 0; + if(x < 0) { + r = -x; + sign++; + } else + r = x; + while(r >= y) { + rfr = math·frexp(r, &rexp); + r -= math·ldexp(y, rexp - yexp - (rfr < yfr)); + } + if(sign) + r = -r; + return r; +} |