[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;
	ctf_align_pos(pos, float_declaration->p.alignment);
	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;
	}
	ctf_align_pos(pos, float_declaration->p.alignment);
	ret = _ctf_float_copy(ppos, float_definition, &srcp.parent, tmpfloat);

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

double bt_get_float(const struct bt_definition *field)
{
	struct definition_float *definition =
		container_of(field, struct definition_float, p);

	return definition->value;
}

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
6dc2ca62 MD	1	/*
	2	* Common Trace Format
	3	*
	4	* Floating point read/write functions.
	5	*
64fa3fec MD	6	* Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
	7	*
	8	* Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6dc2ca62	9	*
ccd7e1c8 MD	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:
de0ba614	16	*
ccd7e1c8 MD	17	* The above copyright notice and this permission notice shall be included in
ccd7e1c8 MD	18	* all copies or substantial portions of the Software.
6dc2ca62	19	*
c462e188 MD	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	*
de0ba614	28	* Reference: ISO C99 standard 5.2.4
6dc2ca62 MD	29	*/
6dc2ca62 MD	30
d79865b9	31	#include <babeltrace/ctf/types.h>
6dc2ca62	32	#include <glib.h>
de0ba614	33	#include <float.h> /* C99 floating point definitions */
a3dbc794	34	#include <limits.h> /* C99 limits */
9b0422a0	35	#include <babeltrace/endian.h>
f530d9ce	36	#include <pthread.h>
6dc2ca62	37
de0ba614 MD	38	/*
de0ba614 MD	39	* This library is limited to binary representation of floating point values.
f72803ca MD	40	* We use hardware support for conversion between 32 and 64-bit floating
f72803ca MD	41	* point values.
de0ba614 MD	42	*/
de0ba614 MD	43
6dc2ca62 MD	44	/*
6dc2ca62 MD	45	* Aliasing float/double and unsigned long is not strictly permitted by strict
f6625916	46	* aliasing, but in practice declaration prunning is well supported, and this permits
6dc2ca62 MD	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
de0ba614 MD	54	#if (FLT_RADIX != 2)
	55
	56	#error "Unsupported floating point radix"
	57
6dc2ca62	58	#endif
6dc2ca62 MD	59
6dc2ca62 MD	60	union doubleIEEE754 {
f72803ca MD	61	double vd;
f72803ca MD	62	float vf;
6dc2ca62 MD	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
f530d9ce JD	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
f72803ca MD	76	static struct declaration_float *static_float_declaration,
f72803ca MD	77	*static_double_declaration;
d11e9c49	78
de0ba614	79	struct pos_len {
08c82b90	80	size_t len;
de0ba614 MD	81	};
de0ba614 MD	82
f530d9ce JD	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
1cf393f6	99	static int _ctf_float_copy(struct bt_stream_pos *destp,
c5e74408	100	struct definition_float *dest_definition,
1cf393f6	101	struct bt_stream_pos *srcp,
c5e74408	102	const struct definition_float *src_definition)
6dc2ca62	103	{
c5e74408 MD	104	int ret;
c5e74408 MD	105
f72803ca MD	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);
11d43b90	113	/* Read */
d11e9c49	114	if (src_definition->declaration->byte_order == LITTLE_ENDIAN) {
c5e74408 MD	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;
de0ba614	124	} else {
c5e74408 MD	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;
6dc2ca62	134	}
d11e9c49 MD	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
11d43b90	143	/* Write */
d11e9c49	144	if (dest_definition->declaration->byte_order == LITTLE_ENDIAN) {
c5e74408 MD	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;
de0ba614	154	} else {
c5e74408 MD	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;
6dc2ca62	164	}
c5e74408	165	return 0;
11d43b90	166	}
de0ba614	167
0d69b916	168	int ctf_float_read(struct bt_stream_pos ppos, struct bt_definition definition)
6dc2ca62	169	{
d11e9c49 MD	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);
f72803ca	175	union doubleIEEE754 u;
0d69b916	176	struct bt_definition *tmpdef;
f72803ca	177	struct definition_float *tmpfloat;
46322b33	178	struct ctf_stream_pos destp;
aee35fcc	179	struct mmap_align mma;
c5e74408	180	int ret;
11d43b90	181
f530d9ce	182	float_lock();
f72803ca MD	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:
f530d9ce JD	195	ret = -EINVAL;
f530d9ce JD	196	goto end;
f72803ca MD	197	}
f72803ca MD	198	tmpfloat = container_of(tmpdef, struct definition_float, p);
86b06ede	199	memset(&destp, 0, sizeof(destp));
ca334c72	200	ctf_init_pos(&destp, NULL, -1, O_RDWR);
aee35fcc MD	201	mmap_align_set_addr(&mma, (char *) u.bits);
aee35fcc MD	202	destp.base_mma = &mma;
f72803ca	203	destp.packet_size = sizeof(u) * CHAR_BIT;
d11e9c49	204	ctf_align_pos(pos, float_declaration->p.alignment);
c5e74408	205	ret = _ctf_float_copy(&destp.parent, tmpfloat, ppos, float_definition);
f72803ca MD	206	switch (float_declaration->mantissa->len + 1) {
	207	case FLT_MANT_DIG:
	208	float_definition->value = u.vf;
	209	break;
	210	case DBL_MANT_DIG:
	211	float_definition->value = u.vd;
	212	break;
	213	default:
f530d9ce JD	214	ret = -EINVAL;
f530d9ce JD	215	goto end_unref;
f72803ca	216	}
f530d9ce JD	217
f530d9ce JD	218	end_unref:
13fad8b6	219	bt_definition_unref(tmpdef);
f530d9ce JD	220	end:
f530d9ce JD	221	float_unlock();
c5e74408	222	return ret;
de0ba614 MD	223	}
de0ba614 MD	224
0d69b916	225	int ctf_float_write(struct bt_stream_pos ppos, struct bt_definition definition)
de0ba614	226	{
d11e9c49 MD	227	struct definition_float *float_definition =
	228	container_of(definition, struct definition_float, p);
	229	const struct declaration_float *float_declaration =
	230	float_definition->declaration;
	231	struct ctf_stream_pos *pos = ctf_pos(ppos);
f72803ca	232	union doubleIEEE754 u;
0d69b916	233	struct bt_definition *tmpdef;
f72803ca	234	struct definition_float *tmpfloat;
27611b66	235	struct ctf_stream_pos srcp = { { 0 } };
aee35fcc	236	struct mmap_align mma;
c5e74408	237	int ret;
11d43b90	238
f530d9ce	239	float_lock();
f72803ca MD	240	switch (float_declaration->mantissa->len + 1) {
	241	case FLT_MANT_DIG:
	242	tmpdef = static_float_declaration->p.definition_new(
	243	&static_float_declaration->p,
	244	NULL, 0, 0, "__tmpfloat");
	245	break;
	246	case DBL_MANT_DIG:
	247	tmpdef = static_double_declaration->p.definition_new(
	248	&static_double_declaration->p,
	249	NULL, 0, 0, "__tmpfloat");
	250	break;
	251	default:
f530d9ce JD	252	ret = -EINVAL;
f530d9ce JD	253	goto end;
f72803ca MD	254	}
f72803ca MD	255	tmpfloat = container_of(tmpdef, struct definition_float, p);
ca334c72	256	ctf_init_pos(&srcp, NULL, -1, O_RDONLY);
aee35fcc MD	257	mmap_align_set_addr(&mma, (char *) u.bits);
aee35fcc MD	258	srcp.base_mma = &mma;
f72803ca MD	259	srcp.packet_size = sizeof(u) * CHAR_BIT;
	260	switch (float_declaration->mantissa->len + 1) {
	261	case FLT_MANT_DIG:
	262	u.vf = float_definition->value;
	263	break;
	264	case DBL_MANT_DIG:
	265	u.vd = float_definition->value;
	266	break;
	267	default:
f530d9ce JD	268	ret = -EINVAL;
f530d9ce JD	269	goto end_unref;
f72803ca	270	}
d11e9c49	271	ctf_align_pos(pos, float_declaration->p.alignment);
c5e74408	272	ret = _ctf_float_copy(ppos, float_definition, &srcp.parent, tmpfloat);
f530d9ce JD	273
f530d9ce JD	274	end_unref:
13fad8b6	275	bt_definition_unref(tmpdef);
f530d9ce JD	276	end:
f530d9ce JD	277	float_unlock();
c5e74408	278	return ret;
de0ba614	279	}
6dc2ca62	280
e5a73b90 JG	281	double bt_get_float(const struct bt_definition *field)
	282	{
	283	struct definition_float *definition =
	284	container_of(field, struct definition_float, p);
	285
	286	return definition->value;
	287	}
	288
2e937fb4	289	static
d11e9c49	290	void __attribute__((constructor)) ctf_float_init(void)
de0ba614	291	{
f72803ca	292	static_float_declaration =
becd02a1	293	bt_float_declaration_new(FLT_MANT_DIG,
f72803ca MD	294	sizeof(float) * CHAR_BIT - FLT_MANT_DIG,
	295	BYTE_ORDER,
	296	__alignof__(float));
	297	static_double_declaration =
becd02a1	298	bt_float_declaration_new(DBL_MANT_DIG,
f72803ca	299	sizeof(double) * CHAR_BIT - DBL_MANT_DIG,
11d43b90	300	BYTE_ORDER,
f72803ca	301	__alignof__(double));
de0ba614 MD	302	}
de0ba614 MD	303
2e937fb4	304	static
d11e9c49	305	void __attribute__((destructor)) ctf_float_fini(void)
de0ba614	306	{
e6b4b4f4 JD	307	bt_declaration_unref(&static_float_declaration->p);
e6b4b4f4 JD	308	bt_declaration_unref(&static_double_declaration->p);
6dc2ca62	309	}