1 // SPDX-License-Identifier: GPL-2.0
25 	0x800000,
26 	0x8b95c2,
27 	0x9837f0,
28 	0xa5fed7,
29 	0xb504f3,
30 	0xc5672a,
31 	0xd744fd,
32 	0xeac0c7
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()
48 		if (exp == 128 && (s & 0x7fffff) != 0)  in eexp2()
49 			return s | 0x400000;	/* return QNaN */  in eexp2()
50 		/* 2^-big = 0, 2^+big = +Inf */  in eexp2()
51 		return (s & 0x80000000)? 0: 0x7f800000;	/* 0 or +Inf */  in eexp2()
53 	if (exp < -23)  in eexp2()
54 		return 0x3f800000;	/* 1.0 */  in eexp2()
57 	pwr = (s & 0x7fffff) | 0x800000;  in eexp2()
58 	if (exp > 0)  in eexp2()
61 		pwr >>= -exp;  in eexp2()
62 	if (s & 0x80000000)  in eexp2()
63 		pwr = -pwr;  in eexp2()
68 		return 0x7f800000;  in eexp2()
69 	if (exp < -23)  in eexp2()
70 		return 0;  in eexp2()
76 	asm("mulhwu %0,%1,%2" : "=r" (frac)  in eexp2()
77 	    : "r" (pwr << 12), "r" (0x172b83ff));  in eexp2()
78 	asm("mulhwu %0,%1,%2" : "=r" (frac) : "r" (frac), "r" (mant));  in eexp2()
81 	if (exp >= 0)  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.
98 	exp = s & 0x7f800000;  in elog2()
99 	mant = s & 0x7fffff;  in elog2()
100 	if (exp == 0x7f800000) {	/* Inf or NaN */  in elog2()
101 		if (mant != 0)  in elog2()
102 			s |= 0x400000;	/* turn NaN into QNaN */  in elog2()
105 	if ((exp | mant) == 0)		/* +0 or -0 */  in elog2()
106 		return 0xff800000;	/* return -Inf */  in elog2()
108 	if (exp == 0) {  in elog2()
110 		asm("cntlzw %0,%1" : "=r" (lz) : "r" (mant));  in elog2()
111 		mant <<= lz - 8;  in elog2()
112 		exp = (-118 - lz) << 23;  in elog2()
114 		mant |= 0x800000;  in elog2()
115 		exp -= 127 << 23;  in elog2()
118 	if (mant >= 0xb504f3) {				/* 2^0.5 * 2^23 */  in elog2()
119 		exp |= 0x400000;			/* 0.5 * 2^23 */  in elog2()
120 		asm("mulhwu %0,%1,%2" : "=r" (mant)  in elog2()
121 		    : "r" (mant), "r" (0xb504f334));	/* 2^-0.5 * 2^32 */  in elog2()
123 	if (mant >= 0x9837f0) {				/* 2^0.25 * 2^23 */  in elog2()
124 		exp |= 0x200000;			/* 0.25 * 2^23 */  in elog2()
125 		asm("mulhwu %0,%1,%2" : "=r" (mant)  in elog2()
126 		    : "r" (mant), "r" (0xd744fccb));	/* 2^-0.25 * 2^32 */  in elog2()
128 	if (mant >= 0x8b95c2) {				/* 2^0.125 * 2^23 */  in elog2()
129 		exp |= 0x100000;			/* 0.125 * 2^23 */  in elog2()
130 		asm("mulhwu %0,%1,%2" : "=r" (mant)  in elog2()
131 		    : "r" (mant), "r" (0xeac0c6e8));	/* 2^-0.125 * 2^32 */  in elog2()
133 	if (mant > 0x800000) {				/* 1.0 * 2^23 */  in elog2()
134 		/* calculate (mant - 1) * 1.381097463 */  in elog2()
135 		/* 1.381097463 == 0.125 / (2^0.125 - 1) */  in elog2()
136 		asm("mulhwu %0,%1,%2" : "=r" (frac)  in elog2()
137 		    : "r" ((mant - 0x800000) << 1), "r" (0xb0c7cd3a));  in elog2()
140 	s = exp & 0x80000000;  in elog2()
141 	if (exp != 0) {  in elog2()
143 			exp = -exp;  in elog2()
144 		asm("cntlzw %0,%1" : "=r" (lz) : "r" (exp));  in elog2()
145 		lz = 8 - lz;  in elog2()
146 		if (lz > 0)  in elog2()
148 		else if (lz < 0)  in elog2()
149 			exp <<= -lz;  in elog2()
161 	exp = (x >> 23) & 0xff;  in ctsxs()
162 	mant = x & 0x7fffff;  in ctsxs()
163 	if (exp == 255 && mant != 0)  in ctsxs()
164 		return 0;		/* NaN -> 0 */  in ctsxs()
165 	exp = exp - 127 + scale;  in ctsxs()
166 	if (exp < 0)  in ctsxs()
167 		return 0;		/* round towards zero */  in ctsxs()
169 		/* saturate, unless the result would be -2^31 */  in ctsxs()
170 		if (x + (scale << 23) != 0xcf000000)  in ctsxs()
172 		return (x & 0x80000000)? 0x80000000: 0x7fffffff;  in ctsxs()
174 	mant |= 0x800000;  in ctsxs()
175 	mant = (mant << 7) >> (30 - exp);  in ctsxs()
176 	return (x & 0x80000000)? -mant: mant;  in ctsxs()
184 	exp = (x >> 23) & 0xff;  in ctuxs()
185 	mant = x & 0x7fffff;  in ctuxs()
186 	if (exp == 255 && mant != 0)  in ctuxs()
187 		return 0;		/* NaN -> 0 */  in ctuxs()
188 	exp = exp - 127 + scale;  in ctuxs()
189 	if (exp < 0)  in ctuxs()
190 		return 0;		/* round towards zero */  in ctuxs()
191 	if (x & 0x80000000) {  in ctuxs()
192 		/* negative => saturate to 0 */  in ctuxs()
194 		return 0;  in ctuxs()
199 		return 0xffffffff;  in ctuxs()
201 	mant |= 0x800000;  in ctuxs()
202 	mant = (mant << 8) >> (31 - exp);  in ctuxs()
206 /* Round to floating integer, towards 0 */
211 	exp = ((x >> 23) & 0xff) - 127;  in rfiz()
212 	if (exp == 128 && (x & 0x7fffff) != 0)  in rfiz()
213 		return x | 0x400000;	/* NaN -> make it a QNaN */  in rfiz()
216 	if (exp < 0)  in rfiz()
217 		return x & 0x80000000;	/* |x| < 1.0 rounds to 0 */  in rfiz()
218 	return x & ~(0x7fffff >> exp);  in rfiz()
221 /* Round to floating integer, towards +/- Inf */
226 	exp = ((x >> 23) & 0xff) - 127;  in rfii()
227 	if (exp == 128 && (x & 0x7fffff) != 0)  in rfii()
228 		return x | 0x400000;	/* NaN -> make it a QNaN */  in rfii()
231 	if ((x & 0x7fffffff) == 0)  in rfii()
232 		return x;		/* +/-0 -> +/-0 */  in rfii()
233 	if (exp < 0)  in rfii()
234 		/* 0 < |x| < 1.0 rounds to +/- 1.0 */  in rfii()
235 		return (x & 0x80000000) | 0x3f800000;  in rfii()
236 	mask = 0x7fffff >> exp;  in rfii()
237 	/* mantissa overflows into exponent - that's OK,  in rfii()
247 	exp = ((x >> 23) & 0xff) - 127;  in rfin()
248 	if (exp == 128 && (x & 0x7fffff) != 0)  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()
256 		return (x & 0x80000000) | 0x3f800000;  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()
275 	vd = (word >> 21) & 0x1f;  in emulate_altivec()
276 	va = (word >> 16) & 0x1f;  in emulate_altivec()
277 	vb = (word >> 11) & 0x1f;  in emulate_altivec()
278 	vc = (word >> 6) & 0x1f;  in emulate_altivec()
280 	vrs = current->thread.vr_state.vr;  in emulate_altivec()
281 	switch (word & 0x3f) {  in emulate_altivec()
284 		case 0:	/* vaddfp */  in emulate_altivec()
297 			for (i = 0; i < 4; ++i)  in emulate_altivec()
301 			for (i = 0; i < 4; ++i)  in emulate_altivec()
305 			for (i = 0; i < 4; ++i)  in emulate_altivec()
309 			for (i = 0; i < 4; ++i)  in emulate_altivec()
313 			for (i = 0; i < 4; ++i) {  in emulate_altivec()
315 				x = (x & 0x80000000)? rfiz(x): rfii(x);  in emulate_altivec()
320 			for (i = 0; i < 4; ++i) {  in emulate_altivec()
322 				x = (x & 0x80000000)? rfii(x): rfiz(x);  in emulate_altivec()
327 			for (i = 0; i < 4; ++i)  in emulate_altivec()
329 					&current->thread.vr_state.vscr.u[3]);  in emulate_altivec()
332 			for (i = 0; i < 4; ++i)  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()
350 	return 0;  in emulate_altivec()