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/ilogbl.c | 55 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 lib/libc/src/musl-math/ilogbl.c (limited to 'lib/libc/src/musl-math/ilogbl.c') diff --git a/lib/libc/src/musl-math/ilogbl.c b/lib/libc/src/musl-math/ilogbl.c new file mode 100644 index 0000000..7b1a9cf --- /dev/null +++ b/lib/libc/src/musl-math/ilogbl.c @@ -0,0 +1,55 @@ +#include +#include "libm.h" + +#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 +int ilogbl(long double x) +{ + return ilogb(x); +} +#elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 +int ilogbl(long double x) +{ + #pragma STDC FENV_ACCESS ON + union ldshape u = {x}; + uint64_t m = u.i.m; + int e = u.i.se & 0x7fff; + + if (!e) { + if (m == 0) { + FORCE_EVAL(0/0.0f); + return FP_ILOGB0; + } + /* subnormal x */ + for (e = -0x3fff+1; m>>63 == 0; e--, m<<=1); + return e; + } + if (e == 0x7fff) { + FORCE_EVAL(0/0.0f); + return m<<1 ? FP_ILOGBNAN : INT_MAX; + } + return e - 0x3fff; +} +#elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 +int ilogbl(long double x) +{ + #pragma STDC FENV_ACCESS ON + union ldshape u = {x}; + int e = u.i.se & 0x7fff; + + if (!e) { + if (x == 0) { + FORCE_EVAL(0/0.0f); + return FP_ILOGB0; + } + /* subnormal x */ + x *= 0x1p120; + return ilogbl(x) - 120; + } + if (e == 0x7fff) { + FORCE_EVAL(0/0.0f); + u.i.se = 0; + return u.f ? FP_ILOGBNAN : INT_MAX; + } + return e - 0x3fff; +} +#endif -- cgit v1.2.3