xref: /arch/sparc/kernel/visemul.c

/* visemul.c: Emulation of VIS instructions.
 *
 * Copyright (C) 2006 David S. Miller (davem@davemloft.net)
 */
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/thread_info.h>
#include <linux/perf_event.h>

#include <asm/ptrace.h>
#include <asm/pstate.h>
#include <asm/fpumacro.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>

/* OPF field of various VIS instructions.  */

/* 000111011 - four 16-bit packs  */
#define FPACK16_OPF	0x03b

/* 000111010 - two 32-bit packs  */
#define FPACK32_OPF	0x03a

/* 000111101 - four 16-bit packs  */
#define FPACKFIX_OPF	0x03d

/* 001001101 - four 16-bit expands  */
#define FEXPAND_OPF	0x04d

/* 001001011 - two 32-bit merges */
#define FPMERGE_OPF	0x04b

/* 000110001 - 8-by-16-bit partitoned product  */
#define FMUL8x16_OPF	0x031

/* 000110011 - 8-by-16-bit upper alpha partitioned product  */
#define FMUL8x16AU_OPF	0x033

/* 000110101 - 8-by-16-bit lower alpha partitioned product  */
#define FMUL8x16AL_OPF	0x035

/* 000110110 - upper 8-by-16-bit partitioned product  */
#define FMUL8SUx16_OPF	0x036

/* 000110111 - lower 8-by-16-bit partitioned product  */
#define FMUL8ULx16_OPF	0x037

/* 000111000 - upper 8-by-16-bit partitioned product  */
#define FMULD8SUx16_OPF	0x038

/* 000111001 - lower unsigned 8-by-16-bit partitioned product  */
#define FMULD8ULx16_OPF	0x039

/* 000101000 - four 16-bit compare; set rd if src1 > src2  */
#define FCMPGT16_OPF	0x028

/* 000101100 - two 32-bit compare; set rd if src1 > src2  */
#define FCMPGT32_OPF	0x02c

/* 000100000 - four 16-bit compare; set rd if src1 <= src2  */
#define FCMPLE16_OPF	0x020

/* 000100100 - two 32-bit compare; set rd if src1 <= src2  */
#define FCMPLE32_OPF	0x024

/* 000100010 - four 16-bit compare; set rd if src1 != src2  */
#define FCMPNE16_OPF	0x022

/* 000100110 - two 32-bit compare; set rd if src1 != src2  */
#define FCMPNE32_OPF	0x026

/* 000101010 - four 16-bit compare; set rd if src1 == src2  */
#define FCMPEQ16_OPF	0x02a

/* 000101110 - two 32-bit compare; set rd if src1 == src2  */
#define FCMPEQ32_OPF	0x02e

/* 000000000 - Eight 8-bit edge boundary processing  */
#define EDGE8_OPF	0x000

/* 000000001 - Eight 8-bit edge boundary processing, no CC */
#define EDGE8N_OPF	0x001

/* 000000010 - Eight 8-bit edge boundary processing, little-endian  */
#define EDGE8L_OPF	0x002

/* 000000011 - Eight 8-bit edge boundary processing, little-endian, no CC  */
#define EDGE8LN_OPF	0x003

/* 000000100 - Four 16-bit edge boundary processing  */
#define EDGE16_OPF	0x004

/* 000000101 - Four 16-bit edge boundary processing, no CC  */
#define EDGE16N_OPF	0x005

/* 000000110 - Four 16-bit edge boundary processing, little-endian  */
#define EDGE16L_OPF	0x006

/* 000000111 - Four 16-bit edge boundary processing, little-endian, no CC  */
#define EDGE16LN_OPF	0x007

/* 000001000 - Two 32-bit edge boundary processing  */
#define EDGE32_OPF	0x008

/* 000001001 - Two 32-bit edge boundary processing, no CC  */
#define EDGE32N_OPF	0x009

/* 000001010 - Two 32-bit edge boundary processing, little-endian  */
#define EDGE32L_OPF	0x00a

/* 000001011 - Two 32-bit edge boundary processing, little-endian, no CC  */
#define EDGE32LN_OPF	0x00b

/* 000111110 - distance between 8 8-bit components  */
#define PDIST_OPF	0x03e

/* 000010000 - convert 8-bit 3-D address to blocked byte address  */
#define ARRAY8_OPF	0x010

/* 000010010 - convert 16-bit 3-D address to blocked byte address  */
#define ARRAY16_OPF	0x012

/* 000010100 - convert 32-bit 3-D address to blocked byte address  */
#define ARRAY32_OPF	0x014

/* 000011001 - Set the GSR.MASK field in preparation for a BSHUFFLE  */
#define BMASK_OPF	0x019

/* 001001100 - Permute bytes as specified by GSR.MASK  */
#define BSHUFFLE_OPF	0x04c

#define VIS_OPF_SHIFT	5
#define VIS_OPF_MASK	(0x1ff << VIS_OPF_SHIFT)

#define RS1(INSN)	(((INSN) >> 14) & 0x1f)
#define RS2(INSN)	(((INSN) >>  0) & 0x1f)
#define RD(INSN)	(((INSN) >> 25) & 0x1f)

static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
				       unsigned int rd, int from_kernel)
{
	if (rs2 >= 16 || rs1 >= 16 || rd >= 16) {
		if (from_kernel != 0)
			__asm__ __volatile__("flushw");
		else
			flushw_user();
	}
}

static unsigned long fetch_reg(unsigned int reg, struct pt_regs *regs)
{
	unsigned long value, fp;

	if (reg < 16)
		return (!reg ? 0 : regs->u_regs[reg]);

	fp = regs->u_regs[UREG_FP];

	if (regs->tstate & TSTATE_PRIV) {
		struct reg_window *win;
		win = (struct reg_window *)(fp + STACK_BIAS);
		value = win->locals[reg - 16];
	} else if (!test_thread_64bit_stack(fp)) {
		struct reg_window32 __user *win32;
		win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
		get_user(value, &win32->locals[reg - 16]);
	} else {
		struct reg_window __user *win;
		win = (struct reg_window __user *)(fp + STACK_BIAS);
		get_user(value, &win->locals[reg - 16]);
	}
	return value;
}

static inline unsigned long __user *__fetch_reg_addr_user(unsigned int reg,
							  struct pt_regs *regs)
{
	unsigned long fp = regs->u_regs[UREG_FP];

	BUG_ON(reg < 16);
	BUG_ON(regs->tstate & TSTATE_PRIV);

	if (!test_thread_64bit_stack(fp)) {
		struct reg_window32 __user *win32;
		win32 = (struct reg_window32 __user *)((unsigned long)((u32)fp));
		return (unsigned long __user *)&win32->locals[reg - 16];
	} else {
		struct reg_window __user *win;
		win = (struct reg_window __user *)(fp + STACK_BIAS);
		return &win->locals[reg - 16];
	}
}

static inline unsigned long *__fetch_reg_addr_kern(unsigned int reg,
						   struct pt_regs *regs)
{
	BUG_ON(reg >= 16);
	BUG_ON(regs->tstate & TSTATE_PRIV);

	return &regs->u_regs[reg];
}

static void store_reg(struct pt_regs *regs, unsigned long val, unsigned long rd)
{
	if (rd < 16) {
		unsigned long *rd_kern = __fetch_reg_addr_kern(rd, regs);

		*rd_kern = val;
	} else {
		unsigned long __user *rd_user = __fetch_reg_addr_user(rd, regs);

		if (!test_thread_64bit_stack(regs->u_regs[UREG_FP]))
			__put_user((u32)val, (u32 __user *)rd_user);
		else
			__put_user(val, rd_user);
	}
}

static inline unsigned long fpd_regval(struct fpustate *f,
				       unsigned int insn_regnum)
{
	insn_regnum = (((insn_regnum & 1) << 5) |
		       (insn_regnum & 0x1e));

	return *(unsigned long *) &f->regs[insn_regnum];
}

static inline unsigned long *fpd_regaddr(struct fpustate *f,
					 unsigned int insn_regnum)
{
	insn_regnum = (((insn_regnum & 1) << 5) |
		       (insn_regnum & 0x1e));

	return (unsigned long *) &f->regs[insn_regnum];
}

static inline unsigned int fps_regval(struct fpustate *f,
				      unsigned int insn_regnum)
{
	return f->regs[insn_regnum];
}

static inline unsigned int *fps_regaddr(struct fpustate *f,
					unsigned int insn_regnum)
{
	return &f->regs[insn_regnum];
}

struct edge_tab {
	u16 left, right;
};
static struct edge_tab edge8_tab[8] = {
	{ 0xff, 0x80 },
	{ 0x7f, 0xc0 },
	{ 0x3f, 0xe0 },
	{ 0x1f, 0xf0 },
	{ 0x0f, 0xf8 },
	{ 0x07, 0xfc },
	{ 0x03, 0xfe },
	{ 0x01, 0xff },
};
static struct edge_tab edge8_tab_l[8] = {
	{ 0xff, 0x01 },
	{ 0xfe, 0x03 },
	{ 0xfc, 0x07 },
	{ 0xf8, 0x0f },
	{ 0xf0, 0x1f },
	{ 0xe0, 0x3f },
	{ 0xc0, 0x7f },
	{ 0x80, 0xff },
};
static struct edge_tab edge16_tab[4] = {
	{ 0xf, 0x8 },
	{ 0x7, 0xc },
	{ 0x3, 0xe },
	{ 0x1, 0xf },
};
static struct edge_tab edge16_tab_l[4] = {
	{ 0xf, 0x1 },
	{ 0xe, 0x3 },
	{ 0xc, 0x7 },
	{ 0x8, 0xf },
};
static struct edge_tab edge32_tab[2] = {
	{ 0x3, 0x2 },
	{ 0x1, 0x3 },
};
static struct edge_tab edge32_tab_l[2] = {
	{ 0x3, 0x1 },
	{ 0x2, 0x3 },
};

static void edge(struct pt_regs *regs, unsigned int insn, unsigned int opf)
{
	unsigned long orig_rs1, rs1, orig_rs2, rs2, rd_val;
	u16 left, right;

	maybe_flush_windows(RS1(insn), RS2(insn), RD(insn), 0);
	orig_rs1 = rs1 = fetch_reg(RS1(insn), regs);
	orig_rs2 = rs2 = fetch_reg(RS2(insn), regs);

	if (test_thread_flag(TIF_32BIT)) {
		rs1 = rs1 & 0xffffffff;
		rs2 = rs2 & 0xffffffff;
	}
	switch (opf) {
	default:
	case EDGE8_OPF:
	case EDGE8N_OPF:
		left = edge8_tab[rs1 & 0x7].left;
		right = edge8_tab[rs2 & 0x7].right;
		break;
	case EDGE8L_OPF:
	case EDGE8LN_OPF:
		left = edge8_tab_l[rs1 & 0x7].left;
		right = edge8_tab_l[rs2 & 0x7].right;
		break;

	case EDGE16_OPF:
	case EDGE16N_OPF:
		left = edge16_tab[(rs1 >> 1) & 0x3].left;
		right = edge16_tab[(rs2 >> 1) & 0x3].right;
		break;

	case EDGE16L_OPF:
	case EDGE16LN_OPF:
		left = edge16_tab_l[(rs1 >> 1) & 0x3].left;
		right = edge16_tab_l[(rs2 >> 1) & 0x3].right;
		break;

	case EDGE32_OPF:
	case EDGE32N_OPF:
		left = edge32_tab[(rs1 >> 2) & 0x1].left;
		right = edge32_tab[(rs2 >> 2) & 0x1].right;
		break;

	case EDGE32L_OPF:
	case EDGE32LN_OPF:
		left = edge32_tab_l[(rs1 >> 2) & 0x1].left;
		right = edge32_tab_l[(rs2 >> 2) & 0x1].right;
		break;
	}

	if ((rs1 & ~0x7UL) == (rs2 & ~0x7UL))
		rd_val = right & left;
	else
		rd_val = left;

	store_reg(regs, rd_val, RD(insn));

	switch (opf) {
	case EDGE8_OPF:
	case EDGE8L_OPF:
	case EDGE16_OPF:
	case EDGE16L_OPF:
	case EDGE32_OPF:
	case EDGE32L_OPF: {
		unsigned long ccr, tstate;

		__asm__ __volatile__("subcc	%1, %2, %%g0\n\t"
				     "rd	%%ccr, %0"
				     : "=r" (ccr)
				     : "r" (orig_rs1), "r" (orig_rs2)
				     : "cc");
		tstate = regs->tstate & ~(TSTATE_XCC | TSTATE_ICC);
		regs->tstate = tstate | (ccr << 32UL);
	}
	}
}

static void array(struct pt_regs *regs, unsigned int insn, unsigned int opf)
{
	unsigned long rs1, rs2, rd_val;
	unsigned int bits, bits_mask;

	maybe_flush_windows(RS1(insn), RS2(insn), RD(insn), 0);
	rs1 = fetch_reg(RS1(insn), regs);
	rs2 = fetch_reg(RS2(insn), regs);

	bits = (rs2 > 5 ? 5 : rs2);
	bits_mask = (1UL << bits) - 1UL;

	rd_val = ((((rs1 >> 11) & 0x3) <<  0) |
		  (((rs1 >> 33) & 0x3) <<  2) |
		  (((rs1 >> 55) & 0x1) <<  4) |
		  (((rs1 >> 13) & 0xf) <<  5) |
		  (((rs1 >> 35) & 0xf) <<  9) |
		  (((rs1 >> 56) & 0xf) << 13) |
		  (((rs1 >> 17) & bits_mask) << 17) |
		  (((rs1 >> 39) & bits_mask) << (17 + bits)) |
		  (((rs1 >> 60) & 0xf)       << (17 + (2*bits))));

	switch (opf) {
	case ARRAY16_OPF:
		rd_val <<= 1;
		break;

	case ARRAY32_OPF:
		rd_val <<= 2;
	}

	store_reg(regs, rd_val, RD(insn));
}

static void bmask(struct pt_regs *regs, unsigned int insn)
{
	unsigned long rs1, rs2, rd_val, gsr;

	maybe_flush_windows(RS1(insn), RS2(insn), RD(insn), 0);
	rs1 = fetch_reg(RS1(insn), regs);
	rs2 = fetch_reg(RS2(insn), regs);
	rd_val = rs1 + rs2;

	store_reg(regs, rd_val, RD(insn));

	gsr = current_thread_info()->gsr[0] & 0xffffffff;
	gsr |= rd_val << 32UL;
	current_thread_info()->gsr[0] = gsr;
}

static void bshuffle(struct pt_regs *regs, unsigned int insn)
{
	struct fpustate *f = FPUSTATE;
	unsigned long rs1, rs2, rd_val;
	unsigned long bmask, i;

	bmask = current_thread_info()->gsr[0] >> 32UL;

	rs1 = fpd_regval(f, RS1(insn));
	rs2 = fpd_regval(f, RS2(insn));

	rd_val = 0UL;
	for (i = 0; i < 8; i++) {
		unsigned long which = (bmask >> (i * 4)) & 0xf;
		unsigned long byte;

		if (which < 8)
			byte = (rs1 >> (which * 8)) & 0xff;
		else
			byte = (rs2 >> ((which-8)*8)) & 0xff;
		rd_val |= (byte << (i * 8));
	}

	*fpd_regaddr(f, RD(insn)) = rd_val;
}

static void pdist(struct pt_regs *regs, unsigned int insn)
{
	struct fpustate *f = FPUSTATE;
	unsigned long rs1, rs2, *rd, rd_val;
	unsigned long i;

	rs1 = fpd_regval(f, RS1(insn));
	rs2 = fpd_regval(f, RS2(insn));
	rd = fpd_regaddr(f, RD(insn));

	rd_val = *rd;

	for (i = 0; i < 8; i++) {
		s16 s1, s2;

		s1 = (rs1 >> (56 - (i * 8))) & 0xff;
		s2 = (rs2 >> (56 - (i * 8))) & 0xff;

		/* Absolute value of difference. */
		s1 -= s2;
		if (s1 < 0)
			s1 = ~s1 + 1;

		rd_val += s1;
	}

	*rd = rd_val;
}

static void pformat(struct pt_regs *regs, unsigned int insn, unsigned int opf)
{
	struct fpustate *f = FPUSTATE;
	unsigned long rs1, rs2, gsr, scale, rd_val;

	gsr = current_thread_info()->gsr[0];
	scale = (gsr >> 3) & (opf == FPACK16_OPF ? 0xf : 0x1f);
	switch (opf) {
	case FPACK16_OPF: {
		unsigned long byte;

		rs2 = fpd_regval(f, RS2(insn));
		rd_val = 0;
		for (byte = 0; byte < 4; byte++) {
			unsigned int val;
			s16 src = (rs2 >> (byte * 16UL)) & 0xffffUL;
			int scaled = src << scale;
			int from_fixed = scaled >> 7;

			val = ((from_fixed < 0) ?
			       0 :
			       (from_fixed > 255) ?
			       255 : from_fixed);

			rd_val |= (val << (8 * byte));
		}
		*fps_regaddr(f, RD(insn)) = rd_val;
		break;
	}

	case FPACK32_OPF: {
		unsigned long word;

		rs1 = fpd_regval(f, RS1(insn));
		rs2 = fpd_regval(f, RS2(insn));
		rd_val = (rs1 << 8) & ~(0x000000ff000000ffUL);
		for (word = 0; word < 2; word++) {
			unsigned long val;
			s32 src = (rs2 >> (word * 32UL));
			s64 scaled = src << scale;
			s64 from_fixed = scaled >> 23;

			val = ((from_fixed < 0) ?
			       0 :
			       (from_fixed > 255) ?
			       255 : from_fixed);

			rd_val |= (val << (32 * word));
		}
		*fpd_regaddr(f, RD(insn)) = rd_val;
		break;
	}

	case FPACKFIX_OPF: {
		unsigned long word;

		rs2 = fpd_regval(f, RS2(insn));

		rd_val = 0;
		for (word = 0; word < 2; word++) {
			long val;
			s32 src = (rs2 >> (word * 32UL));
			s64 scaled = src << scale;
			s64 from_fixed = scaled >> 16;

			val = ((from_fixed < -32768) ?
			       -32768 :
			       (from_fixed > 32767) ?
			       32767 : from_fixed);

			rd_val |= ((val & 0xffff) << (word * 16));
		}
		*fps_regaddr(f, RD(insn)) = rd_val;
		break;
	}

	case FEXPAND_OPF: {
		unsigned long byte;

		rs2 = fps_regval(f, RS2(insn));

		rd_val = 0;
		for (byte = 0; byte < 4; byte++) {
			unsigned long val;
			u8 src = (rs2 >> (byte * 8)) & 0xff;

			val = src << 4;

			rd_val |= (val << (byte * 16));
		}
		*fpd_regaddr(f, RD(insn)) = rd_val;
		break;
	}

	case FPMERGE_OPF: {
		rs1 = fps_regval(f, RS1(insn));
		rs2 = fps_regval(f, RS2(insn));

		rd_val = (((rs2 & 0x000000ff) <<  0) |
			  ((rs1 & 0x000000ff) <<  8) |
			  ((rs2 & 0x0000ff00) <<  8) |
			  ((rs1 & 0x0000ff00) << 16) |
			  ((rs2 & 0x00ff0000) << 16) |
			  ((rs1 & 0x00ff0000) << 24) |
			  ((rs2 & 0xff000000) << 24) |
			  ((rs1 & 0xff000000) << 32));
		*fpd_regaddr(f, RD(insn)) = rd_val;
		break;
	}
	}
}

static void pmul(struct pt_regs *regs, unsigned int insn, unsigned int opf)
{
	struct fpustate *f = FPUSTATE;
	unsigned long rs1, rs2, rd_val;

	switch (opf) {
	case FMUL8x16_OPF: {
		unsigned long byte;

		rs1 = fps_regval(f, RS1(insn));
		rs2 = fpd_regval(f, RS2(insn));

		rd_val = 0;
		for (byte = 0; byte < 4; byte++) {
			u16 src1 = (rs1 >> (byte *  8)) & 0x00ff;
			s16 src2 = (rs2 >> (byte * 16)) & 0xffff;
			u32 prod = src1 * src2;
			u16 scaled = ((prod & 0x00ffff00) >> 8);

			/* Round up.  */
			if (prod & 0x80)
				scaled++;
			rd_val |= ((scaled & 0xffffUL) << (byte * 16UL));
		}

		*fpd_regaddr(f, RD(insn)) = rd_val;
		break;
	}

	case FMUL8x16AU_OPF:
	case FMUL8x16AL_OPF: {
		unsigned long byte;
		s16 src2;

		rs1 = fps_regval(f, RS1(insn));
		rs2 = fps_regval(f, RS2(insn));

		rd_val = 0;
		src2 = rs2 >> (opf == FMUL8x16AU_OPF ? 16 : 0);
		for (byte = 0; byte < 4; byte++) {
			u16 src1 = (rs1 >> (byte * 8)) & 0x00ff;
			u32 prod = src1 * src2;
			u16 scaled = ((prod & 0x00ffff00) >> 8);

			/* Round up.  */
			if (prod & 0x80)
				scaled++;
			rd_val |= ((scaled & 0xffffUL) << (byte * 16UL));
		}

		*fpd_regaddr(f, RD(insn)) = rd_val;
		break;
	}

	case FMUL8SUx16_OPF:
	case FMUL8ULx16_OPF: {
		unsigned long byte, ushift;

		rs1 = fpd_regval(f, RS1(insn));
		rs2 = fpd_regval(f, RS2(insn));

		rd_val = 0;
		ushift = (opf == FMUL8SUx16_OPF) ? 8 : 0;
		for (byte = 0; byte < 4; byte++) {
			u16 src1;
			s16 src2;
			u32 prod;
			u16 scaled;

			src1 = ((rs1 >> ((16 * byte) + ushift)) & 0x00ff);
			src2 = ((rs2 >> (16 * byte)) & 0xffff);
			prod = src1 * src2;
			scaled = ((prod & 0x00ffff00) >> 8);

			/* Round up.  */
			if (prod & 0x80)
				scaled++;
			rd_val |= ((scaled & 0xffffUL) << (byte * 16UL));
		}

		*fpd_regaddr(f, RD(insn)) = rd_val;
		break;
	}

	case FMULD8SUx16_OPF:
	case FMULD8ULx16_OPF: {
		unsigned long byte, ushift;

		rs1 = fps_regval(f, RS1(insn));
		rs2 = fps_regval(f, RS2(insn));

		rd_val = 0;
		ushift = (opf == FMULD8SUx16_OPF) ? 8 : 0;
		for (byte = 0; byte < 2; byte++) {
			u16 src1;
			s16 src2;
			u32 prod;
			u16 scaled;

			src1 = ((rs1 >> ((16 * byte) + ushift)) & 0x00ff);
			src2 = ((rs2 >> (16 * byte)) & 0xffff);
			prod = src1 * src2;
			scaled = ((prod & 0x00ffff00) >> 8);

			/* Round up.  */
			if (prod & 0x80)
				scaled++;
			rd_val |= ((scaled & 0xffffUL) <<
				   ((byte * 32UL) + 7UL));
		}
		*fpd_regaddr(f, RD(insn)) = rd_val;
		break;
	}
	}
}

static void pcmp(struct pt_regs *regs, unsigned int insn, unsigned int opf)
{
	struct fpustate *f = FPUSTATE;
	unsigned long rs1, rs2, rd_val, i;

	rs1 = fpd_regval(f, RS1(insn));
	rs2 = fpd_regval(f, RS2(insn));

	rd_val = 0;

	switch (opf) {
	case FCMPGT16_OPF:
		for (i = 0; i < 4; i++) {
			s16 a = (rs1 >> (i * 16)) & 0xffff;
			s16 b = (rs2 >> (i * 16)) & 0xffff;

			if (a > b)
				rd_val |= 8 >> i;
		}
		break;

	case FCMPGT32_OPF:
		for (i = 0; i < 2; i++) {
			s32 a = (rs1 >> (i * 32)) & 0xffffffff;
			s32 b = (rs2 >> (i * 32)) & 0xffffffff;

			if (a > b)
				rd_val |= 2 >> i;
		}
		break;

	case FCMPLE16_OPF:
		for (i = 0; i < 4; i++) {
			s16 a = (rs1 >> (i * 16)) & 0xffff;
			s16 b = (rs2 >> (i * 16)) & 0xffff;

			if (a <= b)
				rd_val |= 8 >> i;
		}
		break;

	case FCMPLE32_OPF:
		for (i = 0; i < 2; i++) {
			s32 a = (rs1 >> (i * 32)) & 0xffffffff;
			s32 b = (rs2 >> (i * 32)) & 0xffffffff;

			if (a <= b)
				rd_val |= 2 >> i;
		}
		break;

	case FCMPNE16_OPF:
		for (i = 0; i < 4; i++) {
			s16 a = (rs1 >> (i * 16)) & 0xffff;
			s16 b = (rs2 >> (i * 16)) & 0xffff;

			if (a != b)
				rd_val |= 8 >> i;
		}
		break;

	case FCMPNE32_OPF:
		for (i = 0; i < 2; i++) {
			s32 a = (rs1 >> (i * 32)) & 0xffffffff;
			s32 b = (rs2 >> (i * 32)) & 0xffffffff;

			if (a != b)
				rd_val |= 2 >> i;
		}
		break;

	case FCMPEQ16_OPF:
		for (i = 0; i < 4; i++) {
			s16 a = (rs1 >> (i * 16)) & 0xffff;
			s16 b = (rs2 >> (i * 16)) & 0xffff;

			if (a == b)
				rd_val |= 8 >> i;
		}
		break;

	case FCMPEQ32_OPF:
		for (i = 0; i < 2; i++) {
			s32 a = (rs1 >> (i * 32)) & 0xffffffff;
			s32 b = (rs2 >> (i * 32)) & 0xffffffff;

			if (a == b)
				rd_val |= 2 >> i;
		}
		break;
	}

	maybe_flush_windows(0, 0, RD(insn), 0);
	store_reg(regs, rd_val, RD(insn));
}

/* Emulate the VIS instructions which are not implemented in
 * hardware on Niagara.
 */
int vis_emul(struct pt_regs *regs, unsigned int insn)
{
	unsigned long pc = regs->tpc;
	unsigned int opf;

	BUG_ON(regs->tstate & TSTATE_PRIV);

	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);

	if (test_thread_flag(TIF_32BIT))
		pc = (u32)pc;

	if (get_user(insn, (u32 __user *) pc))
		return -EFAULT;

	save_and_clear_fpu();

	opf = (insn & VIS_OPF_MASK) >> VIS_OPF_SHIFT;
	switch (opf) {
	default:
		return -EINVAL;

	/* Pixel Formatting Instructions.  */
	case FPACK16_OPF:
	case FPACK32_OPF:
	case FPACKFIX_OPF:
	case FEXPAND_OPF:
	case FPMERGE_OPF:
		pformat(regs, insn, opf);
		break;

	/* Partitioned Multiply Instructions  */
	case FMUL8x16_OPF:
	case FMUL8x16AU_OPF:
	case FMUL8x16AL_OPF:
	case FMUL8SUx16_OPF:
	case FMUL8ULx16_OPF:
	case FMULD8SUx16_OPF:
	case FMULD8ULx16_OPF:
		pmul(regs, insn, opf);
		break;

	/* Pixel Compare Instructions  */
	case FCMPGT16_OPF:
	case FCMPGT32_OPF:
	case FCMPLE16_OPF:
	case FCMPLE32_OPF:
	case FCMPNE16_OPF:
	case FCMPNE32_OPF:
	case FCMPEQ16_OPF:
	case FCMPEQ32_OPF:
		pcmp(regs, insn, opf);
		break;

	/* Edge Handling Instructions  */
	case EDGE8_OPF:
	case EDGE8N_OPF:
	case EDGE8L_OPF:
	case EDGE8LN_OPF:
	case EDGE16_OPF:
	case EDGE16N_OPF:
	case EDGE16L_OPF:
	case EDGE16LN_OPF:
	case EDGE32_OPF:
	case EDGE32N_OPF:
	case EDGE32L_OPF:
	case EDGE32LN_OPF:
		edge(regs, insn, opf);
		break;

	/* Pixel Component Distance  */
	case PDIST_OPF:
		pdist(regs, insn);
		break;

	/* Three-Dimensional Array Addressing Instructions  */
	case ARRAY8_OPF:
	case ARRAY16_OPF:
	case ARRAY32_OPF:
		array(regs, insn, opf);
		break;

	/* Byte Mask and Shuffle Instructions  */
	case BMASK_OPF:
		bmask(regs, insn);
		break;

	case BSHUFFLE_OPF:
		bshuffle(regs, insn);
		break;
	}

	regs->tpc = regs->tnpc;
	regs->tnpc += 4;
	return 0;
}