From bd5969fc876a10b18613302db7087ef3c40f18e1 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Thu, 7 Mar 2024 17:28:00 -0500 Subject: lib: Add mlibc Signed-off-by: Ian Moffett --- lib/mlibc/options/ansi/musl-generic-math/ilogb.c | 26 ++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 lib/mlibc/options/ansi/musl-generic-math/ilogb.c (limited to 'lib/mlibc/options/ansi/musl-generic-math/ilogb.c') diff --git a/lib/mlibc/options/ansi/musl-generic-math/ilogb.c b/lib/mlibc/options/ansi/musl-generic-math/ilogb.c new file mode 100644 index 0000000..64d4015 --- /dev/null +++ b/lib/mlibc/options/ansi/musl-generic-math/ilogb.c @@ -0,0 +1,26 @@ +#include +#include "libm.h" + +int ilogb(double x) +{ + #pragma STDC FENV_ACCESS ON + union {double f; uint64_t i;} u = {x}; + uint64_t i = u.i; + int e = i>>52 & 0x7ff; + + if (!e) { + i <<= 12; + if (i == 0) { + FORCE_EVAL(0/0.0f); + return FP_ILOGB0; + } + /* subnormal x */ + for (e = -0x3ff; i>>63 == 0; e--, i<<=1); + return e; + } + if (e == 0x7ff) { + FORCE_EVAL(0/0.0f); + return i<<12 ? FP_ILOGBNAN : INT_MAX; + } + return e - 0x3ff; +} -- cgit v1.2.3