1*c9945492SAndroid Build Coastguard Worker #include "libm.h" 2*c9945492SAndroid Build Coastguard Worker coshf(float x)3*c9945492SAndroid Build Coastguard Workerfloat coshf(float x) 4*c9945492SAndroid Build Coastguard Worker { 5*c9945492SAndroid Build Coastguard Worker union {float f; uint32_t i;} u = {.f = x}; 6*c9945492SAndroid Build Coastguard Worker uint32_t w; 7*c9945492SAndroid Build Coastguard Worker float t; 8*c9945492SAndroid Build Coastguard Worker 9*c9945492SAndroid Build Coastguard Worker /* |x| */ 10*c9945492SAndroid Build Coastguard Worker u.i &= 0x7fffffff; 11*c9945492SAndroid Build Coastguard Worker x = u.f; 12*c9945492SAndroid Build Coastguard Worker w = u.i; 13*c9945492SAndroid Build Coastguard Worker 14*c9945492SAndroid Build Coastguard Worker /* |x| < log(2) */ 15*c9945492SAndroid Build Coastguard Worker if (w < 0x3f317217) { 16*c9945492SAndroid Build Coastguard Worker if (w < 0x3f800000 - (12<<23)) { 17*c9945492SAndroid Build Coastguard Worker FORCE_EVAL(x + 0x1p120f); 18*c9945492SAndroid Build Coastguard Worker return 1; 19*c9945492SAndroid Build Coastguard Worker } 20*c9945492SAndroid Build Coastguard Worker t = expm1f(x); 21*c9945492SAndroid Build Coastguard Worker return 1 + t*t/(2*(1+t)); 22*c9945492SAndroid Build Coastguard Worker } 23*c9945492SAndroid Build Coastguard Worker 24*c9945492SAndroid Build Coastguard Worker /* |x| < log(FLT_MAX) */ 25*c9945492SAndroid Build Coastguard Worker if (w < 0x42b17217) { 26*c9945492SAndroid Build Coastguard Worker t = expf(x); 27*c9945492SAndroid Build Coastguard Worker return 0.5f*(t + 1/t); 28*c9945492SAndroid Build Coastguard Worker } 29*c9945492SAndroid Build Coastguard Worker 30*c9945492SAndroid Build Coastguard Worker /* |x| > log(FLT_MAX) or nan */ 31*c9945492SAndroid Build Coastguard Worker t = __expo2f(x, 1.0f); 32*c9945492SAndroid Build Coastguard Worker return t; 33*c9945492SAndroid Build Coastguard Worker } 34