From 30634165980deaeead9f4e71e0ff6a5c9d897776 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Mon, 14 Jul 2025 22:39:34 -0400 Subject: usr: libc: Add math.h + musl math impl port Signed-off-by: Ian Moffett --- lib/libc/src/musl-math/floor.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 lib/libc/src/musl-math/floor.c (limited to 'lib/libc/src/musl-math/floor.c') diff --git a/lib/libc/src/musl-math/floor.c b/lib/libc/src/musl-math/floor.c new file mode 100644 index 0000000..14a31cd --- /dev/null +++ b/lib/libc/src/musl-math/floor.c @@ -0,0 +1,31 @@ +#include "libm.h" + +#if FLT_EVAL_METHOD==0 || FLT_EVAL_METHOD==1 +#define EPS DBL_EPSILON +#elif FLT_EVAL_METHOD==2 +#define EPS LDBL_EPSILON +#endif +static const double_t toint = 1/EPS; + +double floor(double x) +{ + union {double f; uint64_t i;} u = {x}; + int e = u.i >> 52 & 0x7ff; + double_t y; + + if (e >= 0x3ff+52 || x == 0) + return x; + /* y = int(x) - x, where int(x) is an integer neighbor of x */ + if (u.i >> 63) + y = x - toint + toint - x; + else + y = x + toint - toint - x; + /* special case because of non-nearest rounding modes */ + if (e <= 0x3ff-1) { + FORCE_EVAL(y); + return u.i >> 63 ? -1 : 0; + } + if (y > 0) + return x + y - 1; + return x + y; +} -- cgit v1.2.3