xref: /aosp_15_r20/external/musl/src/math/acoshl.c (revision c9945492fdd68bbe62686c5b452b4dc1be3f8453)
1*c9945492SAndroid Build Coastguard Worker #include "libm.h"
2*c9945492SAndroid Build Coastguard Worker 
3*c9945492SAndroid Build Coastguard Worker #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
acoshl(long double x)4*c9945492SAndroid Build Coastguard Worker long double acoshl(long double x)
5*c9945492SAndroid Build Coastguard Worker {
6*c9945492SAndroid Build Coastguard Worker 	return acosh(x);
7*c9945492SAndroid Build Coastguard Worker }
8*c9945492SAndroid Build Coastguard Worker #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
9*c9945492SAndroid Build Coastguard Worker /* acosh(x) = log(x + sqrt(x*x-1)) */
acoshl(long double x)10*c9945492SAndroid Build Coastguard Worker long double acoshl(long double x)
11*c9945492SAndroid Build Coastguard Worker {
12*c9945492SAndroid Build Coastguard Worker 	union ldshape u = {x};
13*c9945492SAndroid Build Coastguard Worker 	int e = u.i.se;
14*c9945492SAndroid Build Coastguard Worker 
15*c9945492SAndroid Build Coastguard Worker 	if (e < 0x3fff + 1)
16*c9945492SAndroid Build Coastguard Worker 		/* 0 <= x < 2, invalid if x < 1 */
17*c9945492SAndroid Build Coastguard Worker 		return log1pl(x-1 + sqrtl((x-1)*(x-1)+2*(x-1)));
18*c9945492SAndroid Build Coastguard Worker 	if (e < 0x3fff + 32)
19*c9945492SAndroid Build Coastguard Worker 		/* 2 <= x < 0x1p32 */
20*c9945492SAndroid Build Coastguard Worker 		return logl(2*x - 1/(x+sqrtl(x*x-1)));
21*c9945492SAndroid Build Coastguard Worker 	if (e & 0x8000)
22*c9945492SAndroid Build Coastguard Worker 		/* x < 0 or x = -0, invalid */
23*c9945492SAndroid Build Coastguard Worker 		return (x - x) / (x - x);
24*c9945492SAndroid Build Coastguard Worker 	/* 0x1p32 <= x or nan */
25*c9945492SAndroid Build Coastguard Worker 	return logl(x) + 0.693147180559945309417232121458176568L;
26*c9945492SAndroid Build Coastguard Worker }
27*c9945492SAndroid Build Coastguard Worker #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
28*c9945492SAndroid Build Coastguard Worker // TODO: broken implementation to make things compile
acoshl(long double x)29*c9945492SAndroid Build Coastguard Worker long double acoshl(long double x)
30*c9945492SAndroid Build Coastguard Worker {
31*c9945492SAndroid Build Coastguard Worker 	return acosh(x);
32*c9945492SAndroid Build Coastguard Worker }
33*c9945492SAndroid Build Coastguard Worker #endif
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