[mirror_qemu.git] / target-ppc / dfp_helper.c

/*
 *  PowerPC Decimal Floating Point (DPF) emulation helpers for QEMU.
 *
 *  Copyright (c) 2014 IBM Corporation.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#include "cpu.h"
#include "exec/helper-proto.h"

#define DECNUMDIGITS 34
#include "libdecnumber/decContext.h"
#include "libdecnumber/decNumber.h"
#include "libdecnumber/dpd/decimal32.h"
#include "libdecnumber/dpd/decimal64.h"
#include "libdecnumber/dpd/decimal128.h"

#if defined(HOST_WORDS_BIGENDIAN)
#define HI_IDX 0
#define LO_IDX 1
#else
#define HI_IDX 1
#define LO_IDX 0
#endif

struct PPC_DFP {
    CPUPPCState *env;
    uint64_t t64[2], a64[2], b64[2];
    decNumber t, a, b;
    decContext context;
    uint8_t crbf;
};

static void dfp_prepare_rounding_mode(decContext *context, uint64_t fpscr)
{
    enum rounding rnd;

    switch ((fpscr >> 32) & 0x7) {
    case 0:
        rnd = DEC_ROUND_HALF_EVEN;
        break;
    case 1:
        rnd = DEC_ROUND_DOWN;
        break;
    case 2:
         rnd = DEC_ROUND_CEILING;
         break;
    case 3:
         rnd = DEC_ROUND_FLOOR;
         break;
    case 4:
         rnd = DEC_ROUND_HALF_UP;
         break;
    case 5:
         rnd = DEC_ROUND_HALF_DOWN;
         break;
    case 6:
         rnd = DEC_ROUND_UP;
         break;
    case 7:
         rnd = DEC_ROUND_05UP;
         break;
    default:
        g_assert_not_reached();
    }

    decContextSetRounding(context, rnd);
}

static void dfp_prepare_decimal64(struct PPC_DFP *dfp, uint64_t *a,
                uint64_t *b, CPUPPCState *env)
{
    decContextDefault(&dfp->context, DEC_INIT_DECIMAL64);
    dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
    dfp->env = env;

    if (a) {
        dfp->a64[0] = *a;
        decimal64ToNumber((decimal64 *)dfp->a64, &dfp->a);
    } else {
        dfp->a64[0] = 0;
        decNumberZero(&dfp->a);
    }

    if (b) {
        dfp->b64[0] = *b;
        decimal64ToNumber((decimal64 *)dfp->b64, &dfp->b);
    } else {
        dfp->b64[0] = 0;
        decNumberZero(&dfp->b);
    }
}

static void dfp_prepare_decimal128(struct PPC_DFP *dfp, uint64_t *a,
                uint64_t *b, CPUPPCState *env)
{
    decContextDefault(&dfp->context, DEC_INIT_DECIMAL128);
    dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
    dfp->env = env;

    if (a) {
        dfp->a64[0] = a[HI_IDX];
        dfp->a64[1] = a[LO_IDX];
        decimal128ToNumber((decimal128 *)dfp->a64, &dfp->a);
    } else {
        dfp->a64[0] = dfp->a64[1] = 0;
        decNumberZero(&dfp->a);
    }

    if (b) {
        dfp->b64[0] = b[HI_IDX];
        dfp->b64[1] = b[LO_IDX];
        decimal128ToNumber((decimal128 *)dfp->b64, &dfp->b);
    } else {
        dfp->b64[0] = dfp->b64[1] = 0;
        decNumberZero(&dfp->b);
    }
}

#define FP_FX       (1ull << FPSCR_FX)
#define FP_FEX      (1ull << FPSCR_FEX)
#define FP_OX       (1ull << FPSCR_OX)
#define FP_OE       (1ull << FPSCR_OE)
#define FP_UX       (1ull << FPSCR_UX)
#define FP_UE       (1ull << FPSCR_UE)
#define FP_XX       (1ull << FPSCR_XX)
#define FP_XE       (1ull << FPSCR_XE)
#define FP_ZX       (1ull << FPSCR_ZX)
#define FP_ZE       (1ull << FPSCR_ZE)
#define FP_VX       (1ull << FPSCR_VX)
#define FP_VXSNAN   (1ull << FPSCR_VXSNAN)
#define FP_VXISI    (1ull << FPSCR_VXISI)
#define FP_VXIMZ    (1ull << FPSCR_VXIMZ)
#define FP_VXZDZ    (1ull << FPSCR_VXZDZ)
#define FP_VXIDI    (1ull << FPSCR_VXIDI)
#define FP_VXVC     (1ull << FPSCR_VXVC)
#define FP_VXCVI    (1ull << FPSCR_VXCVI)
#define FP_VE       (1ull << FPSCR_VE)
#define FP_FI       (1ull << FPSCR_FI)

static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
                uint64_t enabled)
{
    dfp->env->fpscr |= (flag | FP_FX);
    if (dfp->env->fpscr & enabled) {
        dfp->env->fpscr |= FP_FEX;
    }
}

static void dfp_set_FPRF_from_FRT_with_context(struct PPC_DFP *dfp,
                decContext *context)
{
    uint64_t fprf = 0;

    /* construct FPRF */
    switch (decNumberClass(&dfp->t, context)) {
    case DEC_CLASS_SNAN:
        fprf = 0x01;
        break;
    case DEC_CLASS_QNAN:
        fprf = 0x11;
        break;
    case DEC_CLASS_NEG_INF:
        fprf = 0x09;
        break;
    case DEC_CLASS_NEG_NORMAL:
        fprf = 0x08;
        break;
    case DEC_CLASS_NEG_SUBNORMAL:
        fprf = 0x18;
        break;
    case DEC_CLASS_NEG_ZERO:
        fprf = 0x12;
        break;
    case DEC_CLASS_POS_ZERO:
        fprf = 0x02;
        break;
    case DEC_CLASS_POS_SUBNORMAL:
        fprf = 0x14;
        break;
    case DEC_CLASS_POS_NORMAL:
        fprf = 0x04;
        break;
    case DEC_CLASS_POS_INF:
        fprf = 0x05;
        break;
    default:
        assert(0); /* should never get here */
    }
    dfp->env->fpscr &= ~(0x1F << 12);
    dfp->env->fpscr |= (fprf << 12);
}

static void dfp_set_FPRF_from_FRT(struct PPC_DFP *dfp)
{
    dfp_set_FPRF_from_FRT_with_context(dfp, &dfp->context);
}

static void dfp_check_for_OX(struct PPC_DFP *dfp)
{
    if (dfp->context.status & DEC_Overflow) {
        dfp_set_FPSCR_flag(dfp, FP_OX, FP_OE);
    }
}

static void dfp_check_for_UX(struct PPC_DFP *dfp)
{
    if (dfp->context.status & DEC_Underflow) {
        dfp_set_FPSCR_flag(dfp, FP_UX, FP_UE);
    }
}

static void dfp_check_for_XX(struct PPC_DFP *dfp)
{
    if (dfp->context.status & DEC_Inexact) {
        dfp_set_FPSCR_flag(dfp, FP_XX | FP_FI, FP_XE);
    }
}

static void dfp_check_for_VXSNAN(struct PPC_DFP *dfp)
{
    if (dfp->context.status & DEC_Invalid_operation) {
        if (decNumberIsSNaN(&dfp->a) || decNumberIsSNaN(&dfp->b)) {
            dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXSNAN, FP_VE);
        }
    }
}

static void dfp_check_for_VXISI(struct PPC_DFP *dfp, int testForSameSign)
{
    if (dfp->context.status & DEC_Invalid_operation) {
        if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
            int same = decNumberClass(&dfp->a, &dfp->context) ==
                       decNumberClass(&dfp->b, &dfp->context);
            if ((same && testForSameSign) || (!same && !testForSameSign)) {
                dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXISI, FP_VE);
            }
        }
    }
}

static void dfp_check_for_VXISI_add(struct PPC_DFP *dfp)
{
    dfp_check_for_VXISI(dfp, 0);
}

#define DFP_HELPER_TAB(op, dnop, postprocs, size)                              \
void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b)      \
{                                                                              \
    struct PPC_DFP dfp;                                                        \
    dfp_prepare_decimal##size(&dfp, a, b, env);                                \
    dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context);                                \
    decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
    postprocs(&dfp);                                                           \
    if (size == 64) {                                                          \
        t[0] = dfp.t64[0];                                                     \
    } else if (size == 128) {                                                  \
        t[0] = dfp.t64[HI_IDX];                                                \
        t[1] = dfp.t64[LO_IDX];                                                \
    }                                                                          \
}

static void ADD_PPs(struct PPC_DFP *dfp)
{
    dfp_set_FPRF_from_FRT(dfp);
    dfp_check_for_OX(dfp);
    dfp_check_for_UX(dfp);
    dfp_check_for_XX(dfp);
    dfp_check_for_VXSNAN(dfp);
    dfp_check_for_VXISI_add(dfp);
}

DFP_HELPER_TAB(dadd, decNumberAdd, ADD_PPs, 64)
DFP_HELPER_TAB(daddq, decNumberAdd, ADD_PPs, 128)
Commit	Line	Data
7b0c0d66 TM	1	/*
	2	* PowerPC Decimal Floating Point (DPF) emulation helpers for QEMU.
	3	*
	4	* Copyright (c) 2014 IBM Corporation.
	5	*
	6	* This library is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU Lesser General Public
	8	* License as published by the Free Software Foundation; either
	9	* version 2 of the License, or (at your option) any later version.
	10	*
	11	* This library is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* Lesser General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU Lesser General Public
	17	* License along with this library; if not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
	20	#include "cpu.h"
	21	#include "exec/helper-proto.h"
	22
	23	#define DECNUMDIGITS 34
	24	#include "libdecnumber/decContext.h"
	25	#include "libdecnumber/decNumber.h"
	26	#include "libdecnumber/dpd/decimal32.h"
	27	#include "libdecnumber/dpd/decimal64.h"
	28	#include "libdecnumber/dpd/decimal128.h"
	29
	30	#if defined(HOST_WORDS_BIGENDIAN)
	31	#define HI_IDX 0
	32	#define LO_IDX 1
	33	#else
	34	#define HI_IDX 1
	35	#define LO_IDX 0
	36	#endif
	37
	38	struct PPC_DFP {
	39	CPUPPCState *env;
	40	uint64_t t64[2], a64[2], b64[2];
	41	decNumber t, a, b;
	42	decContext context;
	43	uint8_t crbf;
	44	};
	45
	46	static void dfp_prepare_rounding_mode(decContext *context, uint64_t fpscr)
	47	{
	48	enum rounding rnd;
	49
	50	switch ((fpscr >> 32) & 0x7) {
	51	case 0:
	52	rnd = DEC_ROUND_HALF_EVEN;
	53	break;
	54	case 1:
	55	rnd = DEC_ROUND_DOWN;
	56	break;
	57	case 2:
	58	rnd = DEC_ROUND_CEILING;
	59	break;
	60	case 3:
	61	rnd = DEC_ROUND_FLOOR;
	62	break;
	63	case 4:
	64	rnd = DEC_ROUND_HALF_UP;
65	break;
66	case 5:
67	rnd = DEC_ROUND_HALF_DOWN;
68	break;
69	case 6:
70	rnd = DEC_ROUND_UP;
71	break;
72	case 7:
73	rnd = DEC_ROUND_05UP;
74	break;
75	default:
76	g_assert_not_reached();
77	}
78
79	decContextSetRounding(context, rnd);
80	}
81
7b0c0d66 TM	82	static void dfp_prepare_decimal64(struct PPC_DFP dfp, uint64_t a,
	83	uint64_t b, CPUPPCState env)
	84	{
	85	decContextDefault(&dfp->context, DEC_INIT_DECIMAL64);
	86	dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
	87	dfp->env = env;
	88
	89	if (a) {
	90	dfp->a64[0] = *a;
	91	decimal64ToNumber((decimal64 *)dfp->a64, &dfp->a);
	92	} else {
	93	dfp->a64[0] = 0;
	94	decNumberZero(&dfp->a);
	95	}
	96
	97	if (b) {
	98	dfp->b64[0] = *b;
	99	decimal64ToNumber((decimal64 *)dfp->b64, &dfp->b);
	100	} else {
	101	dfp->b64[0] = 0;
	102	decNumberZero(&dfp->b);
	103	}
	104	}
	105
7b0c0d66 TM	106	static void dfp_prepare_decimal128(struct PPC_DFP dfp, uint64_t a,
	107	uint64_t b, CPUPPCState env)
	108	{
	109	decContextDefault(&dfp->context, DEC_INIT_DECIMAL128);
	110	dfp_prepare_rounding_mode(&dfp->context, env->fpscr);
	111	dfp->env = env;
	112
	113	if (a) {
	114	dfp->a64[0] = a[HI_IDX];
	115	dfp->a64[1] = a[LO_IDX];
	116	decimal128ToNumber((decimal128 *)dfp->a64, &dfp->a);
	117	} else {
	118	dfp->a64[0] = dfp->a64[1] = 0;
	119	decNumberZero(&dfp->a);
	120	}
	121
	122	if (b) {
	123	dfp->b64[0] = b[HI_IDX];
	124	dfp->b64[1] = b[LO_IDX];
	125	decimal128ToNumber((decimal128 *)dfp->b64, &dfp->b);
	126	} else {
	127	dfp->b64[0] = dfp->b64[1] = 0;
	128	decNumberZero(&dfp->b);
	129	}
	130	}
27722744 TM	131
	132	#define FP_FX (1ull << FPSCR_FX)
	133	#define FP_FEX (1ull << FPSCR_FEX)
	134	#define FP_OX (1ull << FPSCR_OX)
	135	#define FP_OE (1ull << FPSCR_OE)
	136	#define FP_UX (1ull << FPSCR_UX)
	137	#define FP_UE (1ull << FPSCR_UE)
	138	#define FP_XX (1ull << FPSCR_XX)
	139	#define FP_XE (1ull << FPSCR_XE)
	140	#define FP_ZX (1ull << FPSCR_ZX)
	141	#define FP_ZE (1ull << FPSCR_ZE)
	142	#define FP_VX (1ull << FPSCR_VX)
	143	#define FP_VXSNAN (1ull << FPSCR_VXSNAN)
	144	#define FP_VXISI (1ull << FPSCR_VXISI)
	145	#define FP_VXIMZ (1ull << FPSCR_VXIMZ)
	146	#define FP_VXZDZ (1ull << FPSCR_VXZDZ)
	147	#define FP_VXIDI (1ull << FPSCR_VXIDI)
	148	#define FP_VXVC (1ull << FPSCR_VXVC)
	149	#define FP_VXCVI (1ull << FPSCR_VXCVI)
	150	#define FP_VE (1ull << FPSCR_VE)
	151	#define FP_FI (1ull << FPSCR_FI)
	152
27722744 TM	153	static void dfp_set_FPSCR_flag(struct PPC_DFP *dfp, uint64_t flag,
	154	uint64_t enabled)
	155	{
	156	dfp->env->fpscr \|= (flag \| FP_FX);
	157	if (dfp->env->fpscr & enabled) {
	158	dfp->env->fpscr \|= FP_FEX;
	159	}
	160	}
a9d7ba03 TM	161
	162	static void dfp_set_FPRF_from_FRT_with_context(struct PPC_DFP *dfp,
	163	decContext *context)
	164	{
	165	uint64_t fprf = 0;
	166
	167	/* construct FPRF */
	168	switch (decNumberClass(&dfp->t, context)) {
	169	case DEC_CLASS_SNAN:
	170	fprf = 0x01;
	171	break;
	172	case DEC_CLASS_QNAN:
	173	fprf = 0x11;
	174	break;
	175	case DEC_CLASS_NEG_INF:
	176	fprf = 0x09;
	177	break;
	178	case DEC_CLASS_NEG_NORMAL:
	179	fprf = 0x08;
	180	break;
	181	case DEC_CLASS_NEG_SUBNORMAL:
	182	fprf = 0x18;
	183	break;
	184	case DEC_CLASS_NEG_ZERO:
	185	fprf = 0x12;
	186	break;
	187	case DEC_CLASS_POS_ZERO:
	188	fprf = 0x02;
	189	break;
	190	case DEC_CLASS_POS_SUBNORMAL:
	191	fprf = 0x14;
	192	break;
	193	case DEC_CLASS_POS_NORMAL:
	194	fprf = 0x04;
	195	break;
	196	case DEC_CLASS_POS_INF:
	197	fprf = 0x05;
	198	break;
	199	default:
	200	assert(0); /* should never get here */
	201	}
	202	dfp->env->fpscr &= ~(0x1F << 12);
	203	dfp->env->fpscr \|= (fprf << 12);
	204	}
	205
	206	static void dfp_set_FPRF_from_FRT(struct PPC_DFP *dfp)
	207	{
	208	dfp_set_FPRF_from_FRT_with_context(dfp, &dfp->context);
	209	}
	210
	211	static void dfp_check_for_OX(struct PPC_DFP *dfp)
	212	{
	213	if (dfp->context.status & DEC_Overflow) {
	214	dfp_set_FPSCR_flag(dfp, FP_OX, FP_OE);
	215	}
	216	}
	217
	218	static void dfp_check_for_UX(struct PPC_DFP *dfp)
	219	{
	220	if (dfp->context.status & DEC_Underflow) {
	221	dfp_set_FPSCR_flag(dfp, FP_UX, FP_UE);
	222	}
	223	}
	224
225	static void dfp_check_for_XX(struct PPC_DFP *dfp)
226	{
227	if (dfp->context.status & DEC_Inexact) {
228	dfp_set_FPSCR_flag(dfp, FP_XX \| FP_FI, FP_XE);
229	}
230	}
231
232	static void dfp_check_for_VXSNAN(struct PPC_DFP *dfp)
233	{
234	if (dfp->context.status & DEC_Invalid_operation) {
235	if (decNumberIsSNaN(&dfp->a) \|\| decNumberIsSNaN(&dfp->b)) {
236	dfp_set_FPSCR_flag(dfp, FP_VX \| FP_VXSNAN, FP_VE);
237	}
238	}
239	}
240
241	static void dfp_check_for_VXISI(struct PPC_DFP *dfp, int testForSameSign)
242	{
243	if (dfp->context.status & DEC_Invalid_operation) {
244	if (decNumberIsInfinite(&dfp->a) && decNumberIsInfinite(&dfp->b)) {
245	int same = decNumberClass(&dfp->a, &dfp->context) ==
246	decNumberClass(&dfp->b, &dfp->context);
247	if ((same && testForSameSign) \|\| (!same && !testForSameSign)) {
248	dfp_set_FPSCR_flag(dfp, FP_VX \| FP_VXISI, FP_VE);
249	}
250	}
251	}
252	}
253
254	static void dfp_check_for_VXISI_add(struct PPC_DFP *dfp)
255	{
256	dfp_check_for_VXISI(dfp, 0);
257	}
258
259	#define DFP_HELPER_TAB(op, dnop, postprocs, size) \
260	void helper_##op(CPUPPCState env, uint64_t t, uint64_t a, uint64_t b) \
261	{ \
262	struct PPC_DFP dfp; \
263	dfp_prepare_decimal##size(&dfp, a, b, env); \
264	dnop(&dfp.t, &dfp.a, &dfp.b, &dfp.context); \
265	decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
266	postprocs(&dfp); \
267	if (size == 64) { \
268	t[0] = dfp.t64[0]; \
269	} else if (size == 128) { \
270	t[0] = dfp.t64[HI_IDX]; \
271	t[1] = dfp.t64[LO_IDX]; \
272	} \
273	}
274
275	static void ADD_PPs(struct PPC_DFP *dfp)
276	{
277	dfp_set_FPRF_from_FRT(dfp);
278	dfp_check_for_OX(dfp);
279	dfp_check_for_UX(dfp);
280	dfp_check_for_XX(dfp);
281	dfp_check_for_VXSNAN(dfp);
282	dfp_check_for_VXISI_add(dfp);
283	}
284
285	DFP_HELPER_TAB(dadd, decNumberAdd, ADD_PPs, 64)
286	DFP_HELPER_TAB(daddq, decNumberAdd, ADD_PPs, 128)