arch/powerpc/kernel/vecemu.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Routines to emulate some Altivec/VMX instructions, specifically
  * those that can trap when given denormalized operands in Java mode.
  */
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <asm/ptrace.h>
 #include <asm/processor.h>
 #include <asm/switch_to.h>
 #include <linux/uaccess.h>
 #include <asm/inst.h>

 /* Functions in vector.S */
 extern void vaddfp(vector128 *dst, vector128 *a, vector128 *b);
 extern void vsubfp(vector128 *dst, vector128 *a, vector128 *b);
 extern void vmaddfp(vector128 *dst, vector128 *a, vector128 *b, vector128 *c);
 extern void vnmsubfp(vector128 *dst, vector128 *a, vector128 *b, vector128 *c);
 extern void vrefp(vector128 *dst, vector128 *src);
 extern void vrsqrtefp(vector128 *dst, vector128 *src);
 extern void vexptep(vector128 *dst, vector128 *src);

 static unsigned int exp2s[8] = {
 	0x800000,
 	0x8b95c2,
 	0x9837f0,
 	0xa5fed7,
 	0xb504f3,
 	0xc5672a,
 	0xd744fd,
 	0xeac0c7
 };

 /*
  * Computes an estimate of 2^x.  The `s' argument is the 32-bit
  * single-precision floating-point representation of x.
  */
 static unsigned int eexp2(unsigned int s)
 {
 	int exp, pwr;
 	unsigned int mant, frac;

 	/* extract exponent field from input */
 	exp = ((s >> 23) & 0xff) - 127;
 	if (exp > 7) {
 		/* check for NaN input */
 		if (exp == 128 && (s & 0x7fffff) != 0)
 			return s | 0x400000;	/* return QNaN */
 		/* 2^-big = 0, 2^+big = +Inf */
 		return (s & 0x80000000)? 0: 0x7f800000;	/* 0 or +Inf */
 	}
 	if (exp < -23)
 		return 0x3f800000;	/* 1.0 */

 	/* convert to fixed point integer in 9.23 representation */
 	pwr = (s & 0x7fffff) | 0x800000;
 	if (exp > 0)
 		pwr <<= exp;
 	else
 		pwr >>= -exp;
 	if (s & 0x80000000)
 		pwr = -pwr;

 	/* extract integer part, which becomes exponent part of result */
 	exp = (pwr >> 23) + 126;
 	if (exp >= 254)
 		return 0x7f800000;
 	if (exp < -23)
 		return 0;

 	/* table lookup on top 3 bits of fraction to get mantissa */
 	mant = exp2s[(pwr >> 20) & 7];

 	/* linear interpolation using remaining 20 bits of fraction */
 	asm("mulhwu %0,%1,%2" : "=r" (frac)
 	    : "r" (pwr << 12), "r" (0x172b83ff));
 	asm("mulhwu %0,%1,%2" : "=r" (frac) : "r" (frac), "r" (mant));
 	mant += frac;

 	if (exp >= 0)
 		return mant + (exp << 23);

 	/* denormalized result */
 	exp = -exp;
 	mant += 1 << (exp - 1);
 	return mant >> exp;
 }

 /*
  * Computes an estimate of log_2(x).  The `s' argument is the 32-bit
  * single-precision floating-point representation of x.
  */
 static unsigned int elog2(unsigned int s)
 {
 	int exp, mant, lz, frac;

 	exp = s & 0x7f800000;
 	mant = s & 0x7fffff;
 	if (exp == 0x7f800000) {	/* Inf or NaN */
 		if (mant != 0)
 			s |= 0x400000;	/* turn NaN into QNaN */
 		return s;
 	}
 	if ((exp | mant) == 0)		/* +0 or -0 */
 		return 0xff800000;	/* return -Inf */

 	if (exp == 0) {
 		/* denormalized */
 		asm("cntlzw %0,%1" : "=r" (lz) : "r" (mant));
 		mant <<= lz - 8;
 		exp = (-118 - lz) << 23;
 	} else {
 		mant |= 0x800000;
 		exp -= 127 << 23;
 	}

 	if (mant >= 0xb504f3) {				/* 2^0.5 * 2^23 */
 		exp |= 0x400000;			/* 0.5 * 2^23 */
 		asm("mulhwu %0,%1,%2" : "=r" (mant)
 		    : "r" (mant), "r" (0xb504f334));	/* 2^-0.5 * 2^32 */
 	}
 	if (mant >= 0x9837f0) {				/* 2^0.25 * 2^23 */
 		exp |= 0x200000;			/* 0.25 * 2^23 */
 		asm("mulhwu %0,%1,%2" : "=r" (mant)
 		    : "r" (mant), "r" (0xd744fccb));	/* 2^-0.25 * 2^32 */
 	}
 	if (mant >= 0x8b95c2) {				/* 2^0.125 * 2^23 */
 		exp |= 0x100000;			/* 0.125 * 2^23 */
 		asm("mulhwu %0,%1,%2" : "=r" (mant)
 		    : "r" (mant), "r" (0xeac0c6e8));	/* 2^-0.125 * 2^32 */
 	}
 	if (mant > 0x800000) {				/* 1.0 * 2^23 */
 		/* calculate (mant - 1) * 1.381097463 */
 		/* 1.381097463 == 0.125 / (2^0.125 - 1) */
 		asm("mulhwu %0,%1,%2" : "=r" (frac)
 		    : "r" ((mant - 0x800000) << 1), "r" (0xb0c7cd3a));
 		exp += frac;
 	}
 	s = exp & 0x80000000;
 	if (exp != 0) {
 		if (s)
 			exp = -exp;
 		asm("cntlzw %0,%1" : "=r" (lz) : "r" (exp));
 		lz = 8 - lz;
 		if (lz > 0)
 			exp >>= lz;
 		else if (lz < 0)
 			exp <<= -lz;
 		s += ((lz + 126) << 23) + exp;
 	}
 	return s;
 }

 #define VSCR_SAT	1

 static int ctsxs(unsigned int x, int scale, unsigned int *vscrp)
 {
 	int exp, mant;

 	exp = (x >> 23) & 0xff;
 	mant = x & 0x7fffff;
 	if (exp == 255 && mant != 0)
 		return 0;		/* NaN -> 0 */
 	exp = exp - 127 + scale;
 	if (exp < 0)
 		return 0;		/* round towards zero */
 	if (exp >= 31) {
 		/* saturate, unless the result would be -2^31 */
 		if (x + (scale << 23) != 0xcf000000)
 			*vscrp |= VSCR_SAT;
 		return (x & 0x80000000)? 0x80000000: 0x7fffffff;
 	}
 	mant |= 0x800000;
 	mant = (mant << 7) >> (30 - exp);
 	return (x & 0x80000000)? -mant: mant;
 }

 static unsigned int ctuxs(unsigned int x, int scale, unsigned int *vscrp)
 {
 	int exp;
 	unsigned int mant;

 	exp = (x >> 23) & 0xff;
 	mant = x & 0x7fffff;
 	if (exp == 255 && mant != 0)
 		return 0;		/* NaN -> 0 */
 	exp = exp - 127 + scale;
 	if (exp < 0)
 		return 0;		/* round towards zero */
 	if (x & 0x80000000) {
 		/* negative => saturate to 0 */
 		*vscrp |= VSCR_SAT;
 		return 0;
 	}
 	if (exp >= 32) {
 		/* saturate */
 		*vscrp |= VSCR_SAT;
 		return 0xffffffff;
 	}
 	mant |= 0x800000;
 	mant = (mant << 8) >> (31 - exp);
 	return mant;
 }

 /* Round to floating integer, towards 0 */
 static unsigned int rfiz(unsigned int x)
 {
 	int exp;

 	exp = ((x >> 23) & 0xff) - 127;
 	if (exp == 128 && (x & 0x7fffff) != 0)
 		return x | 0x400000;	/* NaN -> make it a QNaN */
 	if (exp >= 23)
 		return x;		/* it's an integer already (or Inf) */
 	if (exp < 0)
 		return x & 0x80000000;	/* |x| < 1.0 rounds to 0 */
 	return x & ~(0x7fffff >> exp);
 }

 /* Round to floating integer, towards +/- Inf */
 static unsigned int rfii(unsigned int x)
 {
 	int exp, mask;

 	exp = ((x >> 23) & 0xff) - 127;
 	if (exp == 128 && (x & 0x7fffff) != 0)
 		return x | 0x400000;	/* NaN -> make it a QNaN */
 	if (exp >= 23)
 		return x;		/* it's an integer already (or Inf) */
 	if ((x & 0x7fffffff) == 0)
 		return x;		/* +/-0 -> +/-0 */
 	if (exp < 0)
 		/* 0 < |x| < 1.0 rounds to +/- 1.0 */
 		return (x & 0x80000000) | 0x3f800000;
 	mask = 0x7fffff >> exp;
 	/* mantissa overflows into exponent - that's OK,
 	   it can't overflow into the sign bit */
 	return (x + mask) & ~mask;
 }

 /* Round to floating integer, to nearest */
 static unsigned int rfin(unsigned int x)
 {
 	int exp, half;

 	exp = ((x >> 23) & 0xff) - 127;
 	if (exp == 128 && (x & 0x7fffff) != 0)
 		return x | 0x400000;	/* NaN -> make it a QNaN */
 	if (exp >= 23)
 		return x;		/* it's an integer already (or Inf) */
 	if (exp < -1)
 		return x & 0x80000000;	/* |x| < 0.5 -> +/-0 */
 	if (exp == -1)
 		/* 0.5 <= |x| < 1.0 rounds to +/- 1.0 */
 		return (x & 0x80000000) | 0x3f800000;
 	half = 0x400000 >> exp;
 	/* add 0.5 to the magnitude and chop off the fraction bits */
 	return (x + half) & ~(0x7fffff >> exp);
 }

 int emulate_altivec(struct pt_regs *regs)
 {
 	struct ppc_inst instr;
 	unsigned int i, word;
 	unsigned int va, vb, vc, vd;
 	vector128 *vrs;

 	if (get_user_instr(instr, (void __user *)regs->nip))
 		return -EFAULT;

 	word = ppc_inst_val(instr);
 	if (ppc_inst_primary_opcode(instr) != 4)
 		return -EINVAL;		/* not an altivec instruction */
 	vd = (word >> 21) & 0x1f;
 	va = (word >> 16) & 0x1f;
 	vb = (word >> 11) & 0x1f;
 	vc = (word >> 6) & 0x1f;

 	vrs = current->thread.vr_state.vr;
 	switch (word & 0x3f) {
 	case 10:
 		switch (vc) {
 		case 0:	/* vaddfp */
 			vaddfp(&vrs[vd], &vrs[va], &vrs[vb]);
 			break;
 		case 1:	/* vsubfp */
 			vsubfp(&vrs[vd], &vrs[va], &vrs[vb]);
 			break;
 		case 4:	/* vrefp */
 			vrefp(&vrs[vd], &vrs[vb]);
 			break;
 		case 5:	/* vrsqrtefp */
 			vrsqrtefp(&vrs[vd], &vrs[vb]);
 			break;
 		case 6:	/* vexptefp */
 			for (i = 0; i < 4; ++i)
 				vrs[vd].u[i] = eexp2(vrs[vb].u[i]);
 			break;
 		case 7:	/* vlogefp */
 			for (i = 0; i < 4; ++i)
 				vrs[vd].u[i] = elog2(vrs[vb].u[i]);
 			break;
 		case 8:		/* vrfin */
 			for (i = 0; i < 4; ++i)
 				vrs[vd].u[i] = rfin(vrs[vb].u[i]);
 			break;
 		case 9:		/* vrfiz */
 			for (i = 0; i < 4; ++i)
 				vrs[vd].u[i] = rfiz(vrs[vb].u[i]);
 			break;
 		case 10:	/* vrfip */
 			for (i = 0; i < 4; ++i) {
 				u32 x = vrs[vb].u[i];
 				x = (x & 0x80000000)? rfiz(x): rfii(x);
 				vrs[vd].u[i] = x;
 			}
 			break;
 		case 11:	/* vrfim */
 			for (i = 0; i < 4; ++i) {
 				u32 x = vrs[vb].u[i];
 				x = (x & 0x80000000)? rfii(x): rfiz(x);
 				vrs[vd].u[i] = x;
 			}
 			break;
 		case 14:	/* vctuxs */
 			for (i = 0; i < 4; ++i)
 				vrs[vd].u[i] = ctuxs(vrs[vb].u[i], va,
 					&current->thread.vr_state.vscr.u[3]);
 			break;
 		case 15:	/* vctsxs */
 			for (i = 0; i < 4; ++i)
 				vrs[vd].u[i] = ctsxs(vrs[vb].u[i], va,
 					&current->thread.vr_state.vscr.u[3]);
 			break;
 		default:
 			return -EINVAL;
 		}
 		break;
 	case 46:	/* vmaddfp */
 		vmaddfp(&vrs[vd], &vrs[va], &vrs[vb], &vrs[vc]);
 		break;
 	case 47:	/* vnmsubfp */
 		vnmsubfp(&vrs[vd], &vrs[va], &vrs[vb], &vrs[vc]);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Routines to emulate some Altivec/VMX instructions, specifically
	* those that can trap when given denormalized operands in Java mode.
	*/
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/sched.h>
	#include <asm/ptrace.h>
	#include <asm/processor.h>
	#include <asm/switch_to.h>
	#include <linux/uaccess.h>
	#include <asm/inst.h>

	/* Functions in vector.S */
	extern void vaddfp(vector128 dst, vector128 a, vector128 *b);
	extern void vsubfp(vector128 dst, vector128 a, vector128 *b);
	extern void vmaddfp(vector128 dst, vector128 a, vector128 b, vector128 c);
	extern void vnmsubfp(vector128 dst, vector128 a, vector128 b, vector128 c);
	extern void vrefp(vector128 dst, vector128 src);
	extern void vrsqrtefp(vector128 dst, vector128 src);
	extern void vexptep(vector128 dst, vector128 src);

	static unsigned int exp2s[8] = {
	0x800000,
	0x8b95c2,
	0x9837f0,
	0xa5fed7,
	0xb504f3,
	0xc5672a,
	0xd744fd,
	0xeac0c7
	};

	/*
	* Computes an estimate of 2^x. The `s' argument is the 32-bit
	* single-precision floating-point representation of x.
	*/
	static unsigned int eexp2(unsigned int s)
	{
	int exp, pwr;
	unsigned int mant, frac;

	/* extract exponent field from input */
	exp = ((s >> 23) & 0xff) - 127;
	if (exp > 7) {
	/* check for NaN input */
	if (exp == 128 && (s & 0x7fffff) != 0)
	return s \| 0x400000; /* return QNaN */
	/* 2^-big = 0, 2^+big = +Inf */
	return (s & 0x80000000)? 0: 0x7f800000; /* 0 or +Inf */
	}
	if (exp < -23)
	return 0x3f800000; /* 1.0 */

	/* convert to fixed point integer in 9.23 representation */
	pwr = (s & 0x7fffff) \| 0x800000;
	if (exp > 0)
	pwr <<= exp;
	else
	pwr >>= -exp;
	if (s & 0x80000000)
	pwr = -pwr;

	/* extract integer part, which becomes exponent part of result */
	exp = (pwr >> 23) + 126;
	if (exp >= 254)
	return 0x7f800000;
	if (exp < -23)
	return 0;

	/* table lookup on top 3 bits of fraction to get mantissa */
	mant = exp2s[(pwr >> 20) & 7];

	/* linear interpolation using remaining 20 bits of fraction */
	asm("mulhwu %0,%1,%2" : "=r" (frac)
	: "r" (pwr << 12), "r" (0x172b83ff));
	asm("mulhwu %0,%1,%2" : "=r" (frac) : "r" (frac), "r" (mant));
	mant += frac;

	if (exp >= 0)
	return mant + (exp << 23);

	/* denormalized result */
	exp = -exp;
	mant += 1 << (exp - 1);
	return mant >> exp;
	}

	/*
	* Computes an estimate of log_2(x). The `s' argument is the 32-bit
	* single-precision floating-point representation of x.
	*/
	static unsigned int elog2(unsigned int s)
	{
	int exp, mant, lz, frac;

	exp = s & 0x7f800000;
	mant = s & 0x7fffff;
	if (exp == 0x7f800000) { /* Inf or NaN */
	if (mant != 0)
	s \|= 0x400000; /* turn NaN into QNaN */
	return s;
	}
	if ((exp \| mant) == 0) /* +0 or -0 */
	return 0xff800000; /* return -Inf */

	if (exp == 0) {
	/* denormalized */
	asm("cntlzw %0,%1" : "=r" (lz) : "r" (mant));
	mant <<= lz - 8;
	exp = (-118 - lz) << 23;
	} else {
	mant \|= 0x800000;
	exp -= 127 << 23;
	}

	if (mant >= 0xb504f3) { /* 2^0.5 * 2^23 */
	exp \|= 0x400000; /* 0.5 * 2^23 */
	asm("mulhwu %0,%1,%2" : "=r" (mant)
	: "r" (mant), "r" (0xb504f334)); /* 2^-0.5 * 2^32 */
	}
	if (mant >= 0x9837f0) { /* 2^0.25 * 2^23 */
	exp \|= 0x200000; /* 0.25 * 2^23 */
	asm("mulhwu %0,%1,%2" : "=r" (mant)
	: "r" (mant), "r" (0xd744fccb)); /* 2^-0.25 * 2^32 */
	}
	if (mant >= 0x8b95c2) { /* 2^0.125 * 2^23 */
	exp \|= 0x100000; /* 0.125 * 2^23 */
	asm("mulhwu %0,%1,%2" : "=r" (mant)
	: "r" (mant), "r" (0xeac0c6e8)); /* 2^-0.125 * 2^32 */
	}
	if (mant > 0x800000) { /* 1.0 * 2^23 */
	/* calculate (mant - 1) * 1.381097463 */
	/* 1.381097463 == 0.125 / (2^0.125 - 1) */
	asm("mulhwu %0,%1,%2" : "=r" (frac)
	: "r" ((mant - 0x800000) << 1), "r" (0xb0c7cd3a));
	exp += frac;
	}
	s = exp & 0x80000000;
	if (exp != 0) {
	if (s)
	exp = -exp;
	asm("cntlzw %0,%1" : "=r" (lz) : "r" (exp));
	lz = 8 - lz;
	if (lz > 0)
	exp >>= lz;
	else if (lz < 0)
	exp <<= -lz;
	s += ((lz + 126) << 23) + exp;
	}
	return s;
	}

	#define VSCR_SAT 1

	static int ctsxs(unsigned int x, int scale, unsigned int *vscrp)
	{
	int exp, mant;

	exp = (x >> 23) & 0xff;
	mant = x & 0x7fffff;
	if (exp == 255 && mant != 0)
	return 0; /* NaN -> 0 */
	exp = exp - 127 + scale;
	if (exp < 0)
	return 0; /* round towards zero */
	if (exp >= 31) {
	/* saturate, unless the result would be -2^31 */
	if (x + (scale << 23) != 0xcf000000)
	*vscrp \|= VSCR_SAT;
	return (x & 0x80000000)? 0x80000000: 0x7fffffff;
	}
	mant \|= 0x800000;
	mant = (mant << 7) >> (30 - exp);
	return (x & 0x80000000)? -mant: mant;
	}

	static unsigned int ctuxs(unsigned int x, int scale, unsigned int *vscrp)
	{
	int exp;
	unsigned int mant;

	exp = (x >> 23) & 0xff;
	mant = x & 0x7fffff;
	if (exp == 255 && mant != 0)
	return 0; /* NaN -> 0 */
	exp = exp - 127 + scale;
	if (exp < 0)
	return 0; /* round towards zero */
	if (x & 0x80000000) {
	/* negative => saturate to 0 */
	*vscrp \|= VSCR_SAT;
	return 0;
	}
	if (exp >= 32) {
	/* saturate */
	*vscrp \|= VSCR_SAT;
	return 0xffffffff;
	}
	mant \|= 0x800000;
	mant = (mant << 8) >> (31 - exp);
	return mant;
	}

	/* Round to floating integer, towards 0 */
	static unsigned int rfiz(unsigned int x)
	{
	int exp;

	exp = ((x >> 23) & 0xff) - 127;
	if (exp == 128 && (x & 0x7fffff) != 0)
	return x \| 0x400000; /* NaN -> make it a QNaN */
	if (exp >= 23)
	return x; /* it's an integer already (or Inf) */
	if (exp < 0)
	return x & 0x80000000; /* \|x\| < 1.0 rounds to 0 */
	return x & ~(0x7fffff >> exp);
	}

	/* Round to floating integer, towards +/- Inf */
	static unsigned int rfii(unsigned int x)
	{
	int exp, mask;

	exp = ((x >> 23) & 0xff) - 127;
	if (exp == 128 && (x & 0x7fffff) != 0)
	return x \| 0x400000; /* NaN -> make it a QNaN */
	if (exp >= 23)
	return x; /* it's an integer already (or Inf) */
	if ((x & 0x7fffffff) == 0)
	return x; /* +/-0 -> +/-0 */
	if (exp < 0)
	/* 0 < \|x\| < 1.0 rounds to +/- 1.0 */
	return (x & 0x80000000) \| 0x3f800000;
	mask = 0x7fffff >> exp;
	/* mantissa overflows into exponent - that's OK,
	it can't overflow into the sign bit */
	return (x + mask) & ~mask;
	}

	/* Round to floating integer, to nearest */
	static unsigned int rfin(unsigned int x)
	{
	int exp, half;

	exp = ((x >> 23) & 0xff) - 127;
	if (exp == 128 && (x & 0x7fffff) != 0)
	return x \| 0x400000; /* NaN -> make it a QNaN */
	if (exp >= 23)
	return x; /* it's an integer already (or Inf) */
	if (exp < -1)
	return x & 0x80000000; /* \|x\| < 0.5 -> +/-0 */
	if (exp == -1)
	/* 0.5 <= \|x\| < 1.0 rounds to +/- 1.0 */
	return (x & 0x80000000) \| 0x3f800000;
	half = 0x400000 >> exp;
	/* add 0.5 to the magnitude and chop off the fraction bits */
	return (x + half) & ~(0x7fffff >> exp);
	}

	int emulate_altivec(struct pt_regs *regs)
	{
	struct ppc_inst instr;
	unsigned int i, word;
	unsigned int va, vb, vc, vd;
	vector128 *vrs;

	if (get_user_instr(instr, (void __user *)regs->nip))
	return -EFAULT;

	word = ppc_inst_val(instr);
	if (ppc_inst_primary_opcode(instr) != 4)
	return -EINVAL; /* not an altivec instruction */
	vd = (word >> 21) & 0x1f;
	va = (word >> 16) & 0x1f;
	vb = (word >> 11) & 0x1f;
	vc = (word >> 6) & 0x1f;

	vrs = current->thread.vr_state.vr;
	switch (word & 0x3f) {
	case 10:
	switch (vc) {
	case 0: /* vaddfp */
	vaddfp(&vrs[vd], &vrs[va], &vrs[vb]);
	break;
	case 1: /* vsubfp */
	vsubfp(&vrs[vd], &vrs[va], &vrs[vb]);
	break;
	case 4: /* vrefp */
	vrefp(&vrs[vd], &vrs[vb]);
	break;
	case 5: /* vrsqrtefp */
	vrsqrtefp(&vrs[vd], &vrs[vb]);
	break;
	case 6: /* vexptefp */
	for (i = 0; i < 4; ++i)
	vrs[vd].u[i] = eexp2(vrs[vb].u[i]);
	break;
	case 7: /* vlogefp */
	for (i = 0; i < 4; ++i)
	vrs[vd].u[i] = elog2(vrs[vb].u[i]);
	break;
	case 8: /* vrfin */
	for (i = 0; i < 4; ++i)
	vrs[vd].u[i] = rfin(vrs[vb].u[i]);
	break;
	case 9: /* vrfiz */
	for (i = 0; i < 4; ++i)
	vrs[vd].u[i] = rfiz(vrs[vb].u[i]);
	break;
	case 10: /* vrfip */
	for (i = 0; i < 4; ++i) {
	u32 x = vrs[vb].u[i];
	x = (x & 0x80000000)? rfiz(x): rfii(x);
	vrs[vd].u[i] = x;
	}
	break;
	case 11: /* vrfim */
	for (i = 0; i < 4; ++i) {
	u32 x = vrs[vb].u[i];
	x = (x & 0x80000000)? rfii(x): rfiz(x);
	vrs[vd].u[i] = x;
	}
	break;
	case 14: /* vctuxs */
	for (i = 0; i < 4; ++i)
	vrs[vd].u[i] = ctuxs(vrs[vb].u[i], va,
	&current->thread.vr_state.vscr.u[3]);
	break;
	case 15: /* vctsxs */
	for (i = 0; i < 4; ++i)
	vrs[vd].u[i] = ctsxs(vrs[vb].u[i], va,
	&current->thread.vr_state.vscr.u[3]);
	break;
	default:
	return -EINVAL;
	}
	break;
	case 46: /* vmaddfp */
	vmaddfp(&vrs[vd], &vrs[va], &vrs[vb], &vrs[vc]);
	break;
	case 47: /* vnmsubfp */
	vnmsubfp(&vrs[vd], &vrs[va], &vrs[vb], &vrs[vc]);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}