[babeltrace.git] / formats / ctf / types / float.c

/*
 * Common Trace Format
 *
 * Floating point read/write functions.
 *
 * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
 *
 * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Reference: ISO C99 standard 5.2.4
 */

#include <babeltrace/ctf/types.h>
#include <glib.h>
#include <float.h>	/* C99 floating point definitions */
#include <limits.h>	/* C99 limits */
#include <babeltrace/endian.h>
#include <pthread.h>

/*
 * This library is limited to binary representation of floating point values.
 * We use hardware support for conversion between 32 and 64-bit floating
 * point values.
 */

/*
 * Aliasing float/double and unsigned long is not strictly permitted by strict
 * aliasing, but in practice declaration prunning is well supported, and this permits
 * us to use per-word read/writes rather than per-byte.
 */

#if defined(__GNUC__) || defined(__MINGW32__) || defined(_MSC_VER)
#define HAS_TYPE_PRUNING
#endif

#if (FLT_RADIX != 2)

#error "Unsupported floating point radix"

#endif

union doubleIEEE754 {
	double vd;
	float vf;
#ifdef HAS_TYPE_PRUNING
	unsigned long bits[(sizeof(double) + sizeof(unsigned long) - 1) / sizeof(unsigned long)];
#else
	unsigned char bits[sizeof(double)];
#endif
};

/*
 * This mutex protects the static temporary float and double
 * declarations (static_float_declaration and static_double_declaration).
 */
static pthread_mutex_t float_mutex = PTHREAD_MUTEX_INITIALIZER;

static struct declaration_float *static_float_declaration,
		*static_double_declaration;

struct pos_len {
	size_t len;
};

static void float_lock(void)
{
	int ret;

	ret = pthread_mutex_lock(&float_mutex);
	assert(!ret);
}

static void float_unlock(void)
{
	int ret;

	ret = pthread_mutex_unlock(&float_mutex);
	assert(!ret);
}

static int _ctf_float_copy(struct bt_stream_pos *destp,
		    struct definition_float *dest_definition,
		    struct bt_stream_pos *srcp,
		    const struct definition_float *src_definition)
{
	int ret;

	/* We only support copy of same-size floats for now */
	assert(src_definition->declaration->sign->len ==
		dest_definition->declaration->sign->len);
	assert(src_definition->declaration->exp->len ==
		dest_definition->declaration->exp->len);
	assert(src_definition->declaration->mantissa->len ==
		dest_definition->declaration->mantissa->len);
	/* Read */
	if (src_definition->declaration->byte_order == LITTLE_ENDIAN) {
		ret = ctf_integer_read(srcp, &src_definition->mantissa->p);
		if (ret)
			return ret;
		ret = ctf_integer_read(srcp, &src_definition->exp->p);
		if (ret)
			return ret;
		ret = ctf_integer_read(srcp, &src_definition->sign->p);
		if (ret)
			return ret;
	} else {
		ret = ctf_integer_read(srcp, &src_definition->sign->p);
		if (ret)
			return ret;
		ret = ctf_integer_read(srcp, &src_definition->exp->p);
		if (ret)
			return ret;
		ret = ctf_integer_read(srcp, &src_definition->mantissa->p);
		if (ret)
			return ret;
	}

	dest_definition->mantissa->value._unsigned =
		src_definition->mantissa->value._unsigned;
	dest_definition->exp->value._signed =
		src_definition->exp->value._signed;
	dest_definition->sign->value._unsigned =
		src_definition->sign->value._unsigned;

	/* Write */
	if (dest_definition->declaration->byte_order == LITTLE_ENDIAN) {
		ret = ctf_integer_write(destp, &dest_definition->mantissa->p);
		if (ret)
			return ret;
		ret = ctf_integer_write(destp, &dest_definition->exp->p);
		if (ret)
			return ret;
		ret = ctf_integer_write(destp, &dest_definition->sign->p);
		if (ret)
			return ret;
	} else {
		ret = ctf_integer_write(destp, &dest_definition->sign->p);
		if (ret)
			return ret;
		ret = ctf_integer_write(destp, &dest_definition->exp->p);
		if (ret)
			return ret;
		ret = ctf_integer_write(destp, &dest_definition->mantissa->p);
		if (ret)
			return ret;
	}
	return 0;
}

int ctf_float_read(struct bt_stream_pos *ppos, struct bt_definition *definition)
{
	struct definition_float *float_definition =
		container_of(definition, struct definition_float, p);
	const struct declaration_float *float_declaration =
		float_definition->declaration;
	struct ctf_stream_pos *pos = ctf_pos(ppos);
	union doubleIEEE754 u;
	struct bt_definition *tmpdef;
	struct definition_float *tmpfloat;
	struct ctf_stream_pos destp;
	struct mmap_align mma;
	int ret;

	float_lock();
	switch (float_declaration->mantissa->len + 1) {
	case FLT_MANT_DIG:
		tmpdef = static_float_declaration->p.definition_new(
				&static_float_declaration->p,
				NULL, 0, 0, "__tmpfloat");
		break;
	case DBL_MANT_DIG:
		tmpdef = static_double_declaration->p.definition_new(
				&static_double_declaration->p,
				NULL, 0, 0, "__tmpfloat");
		break;
	default:
		ret = -EINVAL;
		goto end;
	}
	tmpfloat = container_of(tmpdef, struct definition_float, p);
	memset(&destp, 0, sizeof(destp));
	ctf_init_pos(&destp, NULL, -1, O_RDWR);
	mmap_align_set_addr(&mma, (char *) u.bits);
	destp.base_mma = &mma;
	destp.packet_size = sizeof(u) * CHAR_BIT;
	if (!ctf_align_pos(pos, float_declaration->p.alignment)) {
		ret = -EFAULT;
		goto end_unref;
	}
	ret = _ctf_float_copy(&destp.parent, tmpfloat, ppos, float_definition);
	switch (float_declaration->mantissa->len + 1) {
	case FLT_MANT_DIG:
		float_definition->value = u.vf;
		break;
	case DBL_MANT_DIG:
		float_definition->value = u.vd;
		break;
	default:
		ret = -EINVAL;
		goto end_unref;
	}

end_unref:
	bt_definition_unref(tmpdef);
end:
	float_unlock();
	return ret;
}

int ctf_float_write(struct bt_stream_pos *ppos, struct bt_definition *definition)
{
	struct definition_float *float_definition =
		container_of(definition, struct definition_float, p);
	const struct declaration_float *float_declaration =
		float_definition->declaration;
	struct ctf_stream_pos *pos = ctf_pos(ppos);
	union doubleIEEE754 u;
	struct bt_definition *tmpdef;
	struct definition_float *tmpfloat;
	struct ctf_stream_pos srcp = { { 0 } };
	struct mmap_align mma;
	int ret;

	float_lock();
	switch (float_declaration->mantissa->len + 1) {
	case FLT_MANT_DIG:
		tmpdef = static_float_declaration->p.definition_new(
				&static_float_declaration->p,
				NULL, 0, 0, "__tmpfloat");
		break;
	case DBL_MANT_DIG:
		tmpdef = static_double_declaration->p.definition_new(
				&static_double_declaration->p,
				NULL, 0, 0, "__tmpfloat");
		break;
	default:
		ret = -EINVAL;
		goto end;
	}
	tmpfloat = container_of(tmpdef, struct definition_float, p);
	ctf_init_pos(&srcp, NULL, -1, O_RDONLY);
	mmap_align_set_addr(&mma, (char *) u.bits);
	srcp.base_mma = &mma;
	srcp.packet_size = sizeof(u) * CHAR_BIT;
	switch (float_declaration->mantissa->len + 1) {
	case FLT_MANT_DIG:
		u.vf = float_definition->value;
		break;
	case DBL_MANT_DIG:
		u.vd = float_definition->value;
		break;
	default:
		ret = -EINVAL;
		goto end_unref;
	}
	if (!ctf_align_pos(pos, float_declaration->p.alignment)) {
		ret = -EFAULT;
		goto end_unref;
	}
	ret = _ctf_float_copy(ppos, float_definition, &srcp.parent, tmpfloat);

end_unref:
	bt_definition_unref(tmpdef);
end:
	float_unlock();
	return ret;
}

static
void __attribute__((constructor)) ctf_float_init(void)
{
	static_float_declaration =
		bt_float_declaration_new(FLT_MANT_DIG,
				sizeof(float) * CHAR_BIT - FLT_MANT_DIG,
				BYTE_ORDER,
				__alignof__(float));
	static_double_declaration =
		bt_float_declaration_new(DBL_MANT_DIG,
				sizeof(double) * CHAR_BIT - DBL_MANT_DIG,
				BYTE_ORDER,
				__alignof__(double));
}

static
void __attribute__((destructor)) ctf_float_fini(void)
{
	bt_declaration_unref(&static_float_declaration->p);
	bt_declaration_unref(&static_double_declaration->p);
}
Commit	Line	Data
	1	/*
	2	* Common Trace Format
	3	*
	4	* Floating point read/write functions.
	5	*
	6	* Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
	7	*
	8	* Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	9	*
	10	* Permission is hereby granted, free of charge, to any person obtaining a copy
	11	* of this software and associated documentation files (the "Software"), to deal
	12	* in the Software without restriction, including without limitation the rights
	13	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	14	* copies of the Software, and to permit persons to whom the Software is
	15	* furnished to do so, subject to the following conditions:
	16	*
	17	* The above copyright notice and this permission notice shall be included in
	18	* all copies or substantial portions of the Software.
	19	*
	20	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	21	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	23	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	24	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	25	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	26	* SOFTWARE.
	27	*
	28	* Reference: ISO C99 standard 5.2.4
	29	*/
	30
	31	#include <babeltrace/ctf/types.h>
	32	#include <glib.h>
	33	#include <float.h> /* C99 floating point definitions */
	34	#include <limits.h> /* C99 limits */
	35	#include <babeltrace/endian.h>
	36	#include <pthread.h>
	37
	38	/*
	39	* This library is limited to binary representation of floating point values.
	40	* We use hardware support for conversion between 32 and 64-bit floating
	41	* point values.
	42	*/
	43
	44	/*
	45	* Aliasing float/double and unsigned long is not strictly permitted by strict
	46	* aliasing, but in practice declaration prunning is well supported, and this permits
	47	* us to use per-word read/writes rather than per-byte.
	48	*/
	49
	50	#if defined(__GNUC__) \|\| defined(__MINGW32__) \|\| defined(_MSC_VER)
	51	#define HAS_TYPE_PRUNING
	52	#endif
	53
	54	#if (FLT_RADIX != 2)
	55
	56	#error "Unsupported floating point radix"
	57
	58	#endif
	59
	60	union doubleIEEE754 {
	61	double vd;
	62	float vf;
	63	#ifdef HAS_TYPE_PRUNING
	64	unsigned long bits[(sizeof(double) + sizeof(unsigned long) - 1) / sizeof(unsigned long)];
	65	#else
	66	unsigned char bits[sizeof(double)];
	67	#endif
	68	};
	69
	70	/*
	71	* This mutex protects the static temporary float and double
	72	* declarations (static_float_declaration and static_double_declaration).
	73	*/
	74	static pthread_mutex_t float_mutex = PTHREAD_MUTEX_INITIALIZER;
	75
	76	static struct declaration_float *static_float_declaration,
	77	*static_double_declaration;
	78
	79	struct pos_len {
	80	size_t len;
	81	};
	82
	83	static void float_lock(void)
	84	{
	85	int ret;
	86
	87	ret = pthread_mutex_lock(&float_mutex);
	88	assert(!ret);
	89	}
	90
	91	static void float_unlock(void)
	92	{
	93	int ret;
	94
	95	ret = pthread_mutex_unlock(&float_mutex);
	96	assert(!ret);
	97	}
	98
	99	static int _ctf_float_copy(struct bt_stream_pos *destp,
	100	struct definition_float *dest_definition,
	101	struct bt_stream_pos *srcp,
	102	const struct definition_float *src_definition)
	103	{
	104	int ret;
	105
	106	/* We only support copy of same-size floats for now */
	107	assert(src_definition->declaration->sign->len ==
	108	dest_definition->declaration->sign->len);
	109	assert(src_definition->declaration->exp->len ==
	110	dest_definition->declaration->exp->len);
	111	assert(src_definition->declaration->mantissa->len ==
	112	dest_definition->declaration->mantissa->len);
	113	/* Read */
	114	if (src_definition->declaration->byte_order == LITTLE_ENDIAN) {
	115	ret = ctf_integer_read(srcp, &src_definition->mantissa->p);
	116	if (ret)
	117	return ret;
	118	ret = ctf_integer_read(srcp, &src_definition->exp->p);
	119	if (ret)
	120	return ret;
	121	ret = ctf_integer_read(srcp, &src_definition->sign->p);
	122	if (ret)
	123	return ret;
	124	} else {
	125	ret = ctf_integer_read(srcp, &src_definition->sign->p);
	126	if (ret)
	127	return ret;
	128	ret = ctf_integer_read(srcp, &src_definition->exp->p);
	129	if (ret)
	130	return ret;
	131	ret = ctf_integer_read(srcp, &src_definition->mantissa->p);
	132	if (ret)
	133	return ret;
	134	}
	135
	136	dest_definition->mantissa->value._unsigned =
	137	src_definition->mantissa->value._unsigned;
	138	dest_definition->exp->value._signed =
	139	src_definition->exp->value._signed;
	140	dest_definition->sign->value._unsigned =
	141	src_definition->sign->value._unsigned;
	142
	143	/* Write */
	144	if (dest_definition->declaration->byte_order == LITTLE_ENDIAN) {
	145	ret = ctf_integer_write(destp, &dest_definition->mantissa->p);
	146	if (ret)
	147	return ret;
	148	ret = ctf_integer_write(destp, &dest_definition->exp->p);
	149	if (ret)
	150	return ret;
	151	ret = ctf_integer_write(destp, &dest_definition->sign->p);
	152	if (ret)
	153	return ret;
	154	} else {
	155	ret = ctf_integer_write(destp, &dest_definition->sign->p);
	156	if (ret)
	157	return ret;
	158	ret = ctf_integer_write(destp, &dest_definition->exp->p);
	159	if (ret)
	160	return ret;
	161	ret = ctf_integer_write(destp, &dest_definition->mantissa->p);
	162	if (ret)
	163	return ret;
	164	}
	165	return 0;
	166	}
	167
	168	int ctf_float_read(struct bt_stream_pos ppos, struct bt_definition definition)
	169	{
	170	struct definition_float *float_definition =
	171	container_of(definition, struct definition_float, p);
	172	const struct declaration_float *float_declaration =
	173	float_definition->declaration;
	174	struct ctf_stream_pos *pos = ctf_pos(ppos);
	175	union doubleIEEE754 u;
	176	struct bt_definition *tmpdef;
	177	struct definition_float *tmpfloat;
	178	struct ctf_stream_pos destp;
	179	struct mmap_align mma;
	180	int ret;
	181
	182	float_lock();
	183	switch (float_declaration->mantissa->len + 1) {
	184	case FLT_MANT_DIG:
	185	tmpdef = static_float_declaration->p.definition_new(
	186	&static_float_declaration->p,
	187	NULL, 0, 0, "__tmpfloat");
	188	break;
	189	case DBL_MANT_DIG:
	190	tmpdef = static_double_declaration->p.definition_new(
	191	&static_double_declaration->p,
	192	NULL, 0, 0, "__tmpfloat");
	193	break;
	194	default:
	195	ret = -EINVAL;
	196	goto end;
	197	}
	198	tmpfloat = container_of(tmpdef, struct definition_float, p);
	199	memset(&destp, 0, sizeof(destp));
	200	ctf_init_pos(&destp, NULL, -1, O_RDWR);
	201	mmap_align_set_addr(&mma, (char *) u.bits);
	202	destp.base_mma = &mma;
	203	destp.packet_size = sizeof(u) * CHAR_BIT;
	204	if (!ctf_align_pos(pos, float_declaration->p.alignment)) {
	205	ret = -EFAULT;
	206	goto end_unref;
	207	}
	208	ret = _ctf_float_copy(&destp.parent, tmpfloat, ppos, float_definition);
	209	switch (float_declaration->mantissa->len + 1) {
	210	case FLT_MANT_DIG:
	211	float_definition->value = u.vf;
	212	break;
	213	case DBL_MANT_DIG:
	214	float_definition->value = u.vd;
	215	break;
	216	default:
	217	ret = -EINVAL;
	218	goto end_unref;
	219	}
	220
	221	end_unref:
	222	bt_definition_unref(tmpdef);
	223	end:
	224	float_unlock();
	225	return ret;
	226	}
	227
	228	int ctf_float_write(struct bt_stream_pos ppos, struct bt_definition definition)
	229	{
	230	struct definition_float *float_definition =
	231	container_of(definition, struct definition_float, p);
	232	const struct declaration_float *float_declaration =
	233	float_definition->declaration;
	234	struct ctf_stream_pos *pos = ctf_pos(ppos);
	235	union doubleIEEE754 u;
	236	struct bt_definition *tmpdef;
	237	struct definition_float *tmpfloat;
	238	struct ctf_stream_pos srcp = { { 0 } };
	239	struct mmap_align mma;
	240	int ret;
	241
	242	float_lock();
	243	switch (float_declaration->mantissa->len + 1) {
	244	case FLT_MANT_DIG:
	245	tmpdef = static_float_declaration->p.definition_new(
	246	&static_float_declaration->p,
	247	NULL, 0, 0, "__tmpfloat");
	248	break;
	249	case DBL_MANT_DIG:
	250	tmpdef = static_double_declaration->p.definition_new(
	251	&static_double_declaration->p,
	252	NULL, 0, 0, "__tmpfloat");
	253	break;
	254	default:
	255	ret = -EINVAL;
	256	goto end;
	257	}
	258	tmpfloat = container_of(tmpdef, struct definition_float, p);
	259	ctf_init_pos(&srcp, NULL, -1, O_RDONLY);
	260	mmap_align_set_addr(&mma, (char *) u.bits);
	261	srcp.base_mma = &mma;
	262	srcp.packet_size = sizeof(u) * CHAR_BIT;
	263	switch (float_declaration->mantissa->len + 1) {
	264	case FLT_MANT_DIG:
	265	u.vf = float_definition->value;
	266	break;
	267	case DBL_MANT_DIG:
	268	u.vd = float_definition->value;
	269	break;
	270	default:
	271	ret = -EINVAL;
	272	goto end_unref;
	273	}
	274	if (!ctf_align_pos(pos, float_declaration->p.alignment)) {
	275	ret = -EFAULT;
	276	goto end_unref;
	277	}
	278	ret = _ctf_float_copy(ppos, float_definition, &srcp.parent, tmpfloat);
	279
	280	end_unref:
	281	bt_definition_unref(tmpdef);
	282	end:
	283	float_unlock();
	284	return ret;
	285	}
	286
	287	static
	288	void __attribute__((constructor)) ctf_float_init(void)
	289	{
	290	static_float_declaration =
	291	bt_float_declaration_new(FLT_MANT_DIG,
	292	sizeof(float) * CHAR_BIT - FLT_MANT_DIG,
	293	BYTE_ORDER,
	294	__alignof__(float));
	295	static_double_declaration =
	296	bt_float_declaration_new(DBL_MANT_DIG,
	297	sizeof(double) * CHAR_BIT - DBL_MANT_DIG,
	298	BYTE_ORDER,
	299	__alignof__(double));
	300	}
	301
	302	static
	303	void __attribute__((destructor)) ctf_float_fini(void)
	304	{
	305	bt_declaration_unref(&static_float_declaration->p);
	306	bt_declaration_unref(&static_double_declaration->p);
	307	}