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#include "libm.h" #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 long double logbl(long double x) { return logb(x); } #else long double logbl(long double x) { if (!isfinite(x)) return x * x; if (x == 0) return -1/(x+0); return ilogbl(x); } #endif