xref: /aosp_15_r20/external/musl/src/math/nexttowardf.c (revision c9945492fdd68bbe62686c5b452b4dc1be3f8453)
1*c9945492SAndroid Build Coastguard Worker #include "libm.h"
2*c9945492SAndroid Build Coastguard Worker 
nexttowardf(float x,long double y)3*c9945492SAndroid Build Coastguard Worker float nexttowardf(float x, long double y)
4*c9945492SAndroid Build Coastguard Worker {
5*c9945492SAndroid Build Coastguard Worker 	union {float f; uint32_t i;} ux = {x};
6*c9945492SAndroid Build Coastguard Worker 	uint32_t e;
7*c9945492SAndroid Build Coastguard Worker 
8*c9945492SAndroid Build Coastguard Worker 	if (isnan(x) || isnan(y))
9*c9945492SAndroid Build Coastguard Worker 		return x + y;
10*c9945492SAndroid Build Coastguard Worker 	if (x == y)
11*c9945492SAndroid Build Coastguard Worker 		return y;
12*c9945492SAndroid Build Coastguard Worker 	if (x == 0) {
13*c9945492SAndroid Build Coastguard Worker 		ux.i = 1;
14*c9945492SAndroid Build Coastguard Worker 		if (signbit(y))
15*c9945492SAndroid Build Coastguard Worker 			ux.i |= 0x80000000;
16*c9945492SAndroid Build Coastguard Worker 	} else if (x < y) {
17*c9945492SAndroid Build Coastguard Worker 		if (signbit(x))
18*c9945492SAndroid Build Coastguard Worker 			ux.i--;
19*c9945492SAndroid Build Coastguard Worker 		else
20*c9945492SAndroid Build Coastguard Worker 			ux.i++;
21*c9945492SAndroid Build Coastguard Worker 	} else {
22*c9945492SAndroid Build Coastguard Worker 		if (signbit(x))
23*c9945492SAndroid Build Coastguard Worker 			ux.i++;
24*c9945492SAndroid Build Coastguard Worker 		else
25*c9945492SAndroid Build Coastguard Worker 			ux.i--;
26*c9945492SAndroid Build Coastguard Worker 	}
27*c9945492SAndroid Build Coastguard Worker 	e = ux.i & 0x7f800000;
28*c9945492SAndroid Build Coastguard Worker 	/* raise overflow if ux.f is infinite and x is finite */
29*c9945492SAndroid Build Coastguard Worker 	if (e == 0x7f800000)
30*c9945492SAndroid Build Coastguard Worker 		FORCE_EVAL(x+x);
31*c9945492SAndroid Build Coastguard Worker 	/* raise underflow if ux.f is subnormal or zero */
32*c9945492SAndroid Build Coastguard Worker 	if (e == 0)
33*c9945492SAndroid Build Coastguard Worker 		FORCE_EVAL(x*x + ux.f*ux.f);
34*c9945492SAndroid Build Coastguard Worker 	return ux.f;
35*c9945492SAndroid Build Coastguard Worker }
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