1 // SPDX-License-Identifier: GPL-2.0
36  * Computes an estimate of 2^x.  The `s' argument is the 32-bit
37  * single-precision floating-point representation of x.
45 	exp = ((s >> 23) & 0xff) - 127;  in eexp2()
50 		/* 2^-big = 0, 2^+big = +Inf */  in eexp2()
53 	if (exp < -23)  in eexp2()
61 		pwr >>= -exp;  in eexp2()
63 		pwr = -pwr;  in eexp2()
69 	if (exp < -23)  in eexp2()
85 	exp = -exp;  in eexp2()
86 	mant += 1 << (exp - 1);  in eexp2()
91  * Computes an estimate of log_2(x).  The `s' argument is the 32-bit
92  * single-precision floating-point representation of x.
105 	if ((exp | mant) == 0)		/* +0 or -0 */  in elog2()
106 		return 0xff800000;	/* return -Inf */  in elog2()
111 		mant <<= lz - 8;  in elog2()
112 		exp = (-118 - lz) << 23;  in elog2()
115 		exp -= 127 << 23;  in elog2()
121 		    : "r" (mant), "r" (0xb504f334));	/* 2^-0.5 * 2^32 */  in elog2()
126 		    : "r" (mant), "r" (0xd744fccb));	/* 2^-0.25 * 2^32 */  in elog2()
131 		    : "r" (mant), "r" (0xeac0c6e8));	/* 2^-0.125 * 2^32 */  in elog2()
134 		/* calculate (mant - 1) * 1.381097463 */  in elog2()
135 		/* 1.381097463 == 0.125 / (2^0.125 - 1) */  in elog2()
137 		    : "r" ((mant - 0x800000) << 1), "r" (0xb0c7cd3a));  in elog2()
143 			exp = -exp;  in elog2()
145 		lz = 8 - lz;  in elog2()
149 			exp <<= -lz;  in elog2()
164 		return 0;		/* NaN -> 0 */  in ctsxs()
165 	exp = exp - 127 + scale;  in ctsxs()
169 		/* saturate, unless the result would be -2^31 */  in ctsxs()
175 	mant = (mant << 7) >> (30 - exp);  in ctsxs()
176 	return (x & 0x80000000)? -mant: mant;  in ctsxs()
187 		return 0;		/* NaN -> 0 */  in ctuxs()
188 	exp = exp - 127 + scale;  in ctuxs()
202 	mant = (mant << 8) >> (31 - exp);  in ctuxs()
211 	exp = ((x >> 23) & 0xff) - 127;  in rfiz()
213 		return x | 0x400000;	/* NaN -> make it a QNaN */  in rfiz()
221 /* Round to floating integer, towards +/- Inf */
226 	exp = ((x >> 23) & 0xff) - 127;  in rfii()
228 		return x | 0x400000;	/* NaN -> make it a QNaN */  in rfii()
232 		return x;		/* +/-0 -> +/-0 */  in rfii()
234 		/* 0 < |x| < 1.0 rounds to +/- 1.0 */  in rfii()
237 	/* mantissa overflows into exponent - that's OK,  in rfii()
245 	int exp, half;  in rfin()  local
247 	exp = ((x >> 23) & 0xff) - 127;  in rfin()
249 		return x | 0x400000;	/* NaN -> make it a QNaN */  in rfin()
252 	if (exp < -1)  in rfin()
253 		return x & 0x80000000;	/* |x| < 0.5 -> +/-0 */  in rfin()
254 	if (exp == -1)  in rfin()
255 		/* 0.5 <= |x| < 1.0 rounds to +/- 1.0 */  in rfin()
257 	half = 0x400000 >> exp;  in rfin()
259 	return (x + half) & ~(0x7fffff >> exp);  in rfin()
269 	if (get_user_instr(instr, (void __user *)regs->nip))  in emulate_altivec()
270 		return -EFAULT;  in emulate_altivec()
274 		return -EINVAL;		/* not an altivec instruction */  in emulate_altivec()
280 	vrs = current->thread.vr_state.vr;  in emulate_altivec()
329 					&current->thread.vr_state.vscr.u[3]);  in emulate_altivec()
334 					&current->thread.vr_state.vscr.u[3]);  in emulate_altivec()
337 			return -EINVAL;  in emulate_altivec()
347 		return -EINVAL;  in emulate_altivec()