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| author | Damien George <damien.p.george@gmail.com> | 2014-10-31 11:28:50 +0000 |
|---|---|---|
| committer | Damien George <damien.p.george@gmail.com> | 2014-10-31 11:28:50 +0000 |
| commit | 1559a978100762efd84666befd134d5975ae8d4b (patch) | |
| tree | b5910a620f1532ae722b865c1f71988e3f4d1e1c /lib | |
| parent | fa73c9cb25f05ffa6df4c5d15cc754885c3415ff (diff) | |
| download | micropython-1559a978100762efd84666befd134d5975ae8d4b.tar.gz micropython-1559a978100762efd84666befd134d5975ae8d4b.zip | |
py: Add builtin round function.
Addresses issue #934.
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/libm/roundf.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/lib/libm/roundf.c b/lib/libm/roundf.c new file mode 100644 index 0000000000..3da1f0595e --- /dev/null +++ b/lib/libm/roundf.c @@ -0,0 +1,33 @@ +/*****************************************************************************/ +/*****************************************************************************/ +// roundf from musl-0.9.15 +/*****************************************************************************/ +/*****************************************************************************/ + +#include "libm.h" + +float roundf(float x) +{ + union {float f; uint32_t i;} u = {x}; + int e = u.i >> 23 & 0xff; + float_t y; + + if (e >= 0x7f+23) + return x; + if (u.i >> 31) + x = -x; + if (e < 0x7f-1) { + FORCE_EVAL(x + 0x1p23f); + return 0*u.f; + } + y = (float)(x + 0x1p23f) - 0x1p23f - x; + if (y > 0.5f) + y = y + x - 1; + else if (y <= -0.5f) + y = y + x + 1; + else + y = y + x; + if (u.i >> 31) + y = -y; + return y; +} |