[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.
 *
 * 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);
}

int _ctf_float_copy(struct stream_pos *destp,
		    struct definition_float *dest_definition,
		    struct 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 stream_pos *ppos, struct 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 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, -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:
	definition_unref(tmpdef);
end:
	float_unlock();
	return ret;
}

int ctf_float_write(struct stream_pos *ppos, struct 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 definition *tmpdef;
	struct definition_float *tmpfloat;
	struct ctf_stream_pos srcp;
	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, -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:
	definition_unref(tmpdef);
end:
	float_unlock();
	return ret;
}

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

void __attribute__((destructor)) ctf_float_fini(void)
{
	declaration_unref(&static_float_declaration->p);
	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	*
de0ba614	20	* Reference: ISO C99 standard 5.2.4
6dc2ca62 MD	21	*/
6dc2ca62 MD	22
d79865b9	23	#include <babeltrace/ctf/types.h>
6dc2ca62	24	#include <glib.h>
de0ba614	25	#include <float.h> /* C99 floating point definitions */
a3dbc794	26	#include <limits.h> /* C99 limits */
9b0422a0	27	#include <babeltrace/endian.h>
f530d9ce	28	#include <pthread.h>
6dc2ca62	29
de0ba614 MD	30	/*
de0ba614 MD	31	* This library is limited to binary representation of floating point values.
f72803ca MD	32	* We use hardware support for conversion between 32 and 64-bit floating
f72803ca MD	33	* point values.
de0ba614 MD	34	*/
de0ba614 MD	35
6dc2ca62 MD	36	/*
6dc2ca62 MD	37	* Aliasing float/double and unsigned long is not strictly permitted by strict
f6625916	38	* aliasing, but in practice declaration prunning is well supported, and this permits
6dc2ca62 MD	39	* us to use per-word read/writes rather than per-byte.
	40	*/
	41
	42	#if defined(__GNUC__) \|\| defined(__MINGW32__) \|\| defined(_MSC_VER)
	43	#define HAS_TYPE_PRUNING
	44	#endif
	45
de0ba614 MD	46	#if (FLT_RADIX != 2)
	47
	48	#error "Unsupported floating point radix"
	49
6dc2ca62	50	#endif
6dc2ca62 MD	51
6dc2ca62 MD	52	union doubleIEEE754 {
f72803ca MD	53	double vd;
f72803ca MD	54	float vf;
6dc2ca62 MD	55	#ifdef HAS_TYPE_PRUNING
	56	unsigned long bits[(sizeof(double) + sizeof(unsigned long) - 1) / sizeof(unsigned long)];
	57	#else
	58	unsigned char bits[sizeof(double)];
	59	#endif
	60	};
	61
f530d9ce JD	62	/*
	63	* This mutex protects the static temporary float and double
	64	* declarations (static_float_declaration and static_double_declaration).
	65	*/
	66	static pthread_mutex_t float_mutex = PTHREAD_MUTEX_INITIALIZER;
	67
f72803ca MD	68	static struct declaration_float *static_float_declaration,
f72803ca MD	69	*static_double_declaration;
d11e9c49	70
de0ba614	71	struct pos_len {
08c82b90	72	size_t len;
de0ba614 MD	73	};
de0ba614 MD	74
f530d9ce JD	75	static void float_lock(void)
	76	{
	77	int ret;
	78
	79	ret = pthread_mutex_lock(&float_mutex);
	80	assert(!ret);
	81	}
	82
	83	static void float_unlock(void)
	84	{
	85	int ret;
	86
	87	ret = pthread_mutex_unlock(&float_mutex);
	88	assert(!ret);
	89	}
	90
c5e74408 MD	91	int _ctf_float_copy(struct stream_pos *destp,
	92	struct definition_float *dest_definition,
	93	struct stream_pos *srcp,
	94	const struct definition_float *src_definition)
6dc2ca62	95	{
c5e74408 MD	96	int ret;
c5e74408 MD	97
f72803ca MD	98	/* We only support copy of same-size floats for now */
	99	assert(src_definition->declaration->sign->len ==
	100	dest_definition->declaration->sign->len);
	101	assert(src_definition->declaration->exp->len ==
	102	dest_definition->declaration->exp->len);
	103	assert(src_definition->declaration->mantissa->len ==
	104	dest_definition->declaration->mantissa->len);
11d43b90	105	/* Read */
d11e9c49	106	if (src_definition->declaration->byte_order == LITTLE_ENDIAN) {
c5e74408 MD	107	ret = ctf_integer_read(srcp, &src_definition->mantissa->p);
	108	if (ret)
	109	return ret;
	110	ret = ctf_integer_read(srcp, &src_definition->exp->p);
	111	if (ret)
	112	return ret;
	113	ret = ctf_integer_read(srcp, &src_definition->sign->p);
	114	if (ret)
	115	return ret;
de0ba614	116	} else {
c5e74408 MD	117	ret = ctf_integer_read(srcp, &src_definition->sign->p);
	118	if (ret)
	119	return ret;
	120	ret = ctf_integer_read(srcp, &src_definition->exp->p);
	121	if (ret)
	122	return ret;
	123	ret = ctf_integer_read(srcp, &src_definition->mantissa->p);
	124	if (ret)
	125	return ret;
6dc2ca62	126	}
d11e9c49 MD	127
	128	dest_definition->mantissa->value._unsigned =
	129	src_definition->mantissa->value._unsigned;
	130	dest_definition->exp->value._signed =
	131	src_definition->exp->value._signed;
	132	dest_definition->sign->value._unsigned =
	133	src_definition->sign->value._unsigned;
	134
11d43b90	135	/* Write */
d11e9c49	136	if (dest_definition->declaration->byte_order == LITTLE_ENDIAN) {
c5e74408 MD	137	ret = ctf_integer_write(destp, &dest_definition->mantissa->p);
	138	if (ret)
	139	return ret;
	140	ret = ctf_integer_write(destp, &dest_definition->exp->p);
	141	if (ret)
	142	return ret;
	143	ret = ctf_integer_write(destp, &dest_definition->sign->p);
	144	if (ret)
	145	return ret;
de0ba614	146	} else {
c5e74408 MD	147	ret = ctf_integer_write(destp, &dest_definition->sign->p);
	148	if (ret)
	149	return ret;
	150	ret = ctf_integer_write(destp, &dest_definition->exp->p);
	151	if (ret)
	152	return ret;
	153	ret = ctf_integer_write(destp, &dest_definition->mantissa->p);
	154	if (ret)
	155	return ret;
6dc2ca62	156	}
c5e74408	157	return 0;
11d43b90	158	}
de0ba614	159
c5e74408	160	int ctf_float_read(struct stream_pos ppos, struct definition definition)
6dc2ca62	161	{
d11e9c49 MD	162	struct definition_float *float_definition =
	163	container_of(definition, struct definition_float, p);
	164	const struct declaration_float *float_declaration =
	165	float_definition->declaration;
	166	struct ctf_stream_pos *pos = ctf_pos(ppos);
f72803ca MD	167	union doubleIEEE754 u;
	168	struct definition *tmpdef;
	169	struct definition_float *tmpfloat;
46322b33	170	struct ctf_stream_pos destp;
aee35fcc	171	struct mmap_align mma;
c5e74408	172	int ret;
11d43b90	173
f530d9ce	174	float_lock();
f72803ca MD	175	switch (float_declaration->mantissa->len + 1) {
	176	case FLT_MANT_DIG:
	177	tmpdef = static_float_declaration->p.definition_new(
	178	&static_float_declaration->p,
	179	NULL, 0, 0, "__tmpfloat");
	180	break;
	181	case DBL_MANT_DIG:
	182	tmpdef = static_double_declaration->p.definition_new(
	183	&static_double_declaration->p,
	184	NULL, 0, 0, "__tmpfloat");
	185	break;
	186	default:
f530d9ce JD	187	ret = -EINVAL;
f530d9ce JD	188	goto end;
f72803ca MD	189	}
f72803ca MD	190	tmpfloat = container_of(tmpdef, struct definition_float, p);
86b06ede	191	memset(&destp, 0, sizeof(destp));
989c73bc	192	ctf_init_pos(&destp, -1, O_RDWR);
aee35fcc MD	193	mmap_align_set_addr(&mma, (char *) u.bits);
aee35fcc MD	194	destp.base_mma = &mma;
f72803ca	195	destp.packet_size = sizeof(u) * CHAR_BIT;
d11e9c49	196	ctf_align_pos(pos, float_declaration->p.alignment);
c5e74408	197	ret = _ctf_float_copy(&destp.parent, tmpfloat, ppos, float_definition);
f72803ca MD	198	switch (float_declaration->mantissa->len + 1) {
	199	case FLT_MANT_DIG:
	200	float_definition->value = u.vf;
	201	break;
	202	case DBL_MANT_DIG:
	203	float_definition->value = u.vd;
	204	break;
	205	default:
f530d9ce JD	206	ret = -EINVAL;
f530d9ce JD	207	goto end_unref;
f72803ca	208	}
f530d9ce JD	209
f530d9ce JD	210	end_unref:
d11e9c49	211	definition_unref(tmpdef);
f530d9ce JD	212	end:
f530d9ce JD	213	float_unlock();
c5e74408	214	return ret;
de0ba614 MD	215	}
de0ba614 MD	216
c5e74408	217	int ctf_float_write(struct stream_pos ppos, struct definition definition)
de0ba614	218	{
d11e9c49 MD	219	struct definition_float *float_definition =
	220	container_of(definition, struct definition_float, p);
	221	const struct declaration_float *float_declaration =
	222	float_definition->declaration;
	223	struct ctf_stream_pos *pos = ctf_pos(ppos);
f72803ca MD	224	union doubleIEEE754 u;
	225	struct definition *tmpdef;
	226	struct definition_float *tmpfloat;
46322b33	227	struct ctf_stream_pos srcp;
aee35fcc	228	struct mmap_align mma;
c5e74408	229	int ret;
11d43b90	230
f530d9ce	231	float_lock();
f72803ca MD	232	switch (float_declaration->mantissa->len + 1) {
	233	case FLT_MANT_DIG:
	234	tmpdef = static_float_declaration->p.definition_new(
	235	&static_float_declaration->p,
	236	NULL, 0, 0, "__tmpfloat");
	237	break;
	238	case DBL_MANT_DIG:
	239	tmpdef = static_double_declaration->p.definition_new(
	240	&static_double_declaration->p,
	241	NULL, 0, 0, "__tmpfloat");
	242	break;
	243	default:
f530d9ce JD	244	ret = -EINVAL;
f530d9ce JD	245	goto end;
f72803ca MD	246	}
f72803ca MD	247	tmpfloat = container_of(tmpdef, struct definition_float, p);
8563e754	248	ctf_init_pos(&srcp, -1, O_RDONLY);
aee35fcc MD	249	mmap_align_set_addr(&mma, (char *) u.bits);
aee35fcc MD	250	srcp.base_mma = &mma;
f72803ca MD	251	srcp.packet_size = sizeof(u) * CHAR_BIT;
	252	switch (float_declaration->mantissa->len + 1) {
	253	case FLT_MANT_DIG:
	254	u.vf = float_definition->value;
	255	break;
	256	case DBL_MANT_DIG:
	257	u.vd = float_definition->value;
	258	break;
	259	default:
f530d9ce JD	260	ret = -EINVAL;
f530d9ce JD	261	goto end_unref;
f72803ca	262	}
d11e9c49	263	ctf_align_pos(pos, float_declaration->p.alignment);
c5e74408	264	ret = _ctf_float_copy(ppos, float_definition, &srcp.parent, tmpfloat);
f530d9ce JD	265
f530d9ce JD	266	end_unref:
d11e9c49	267	definition_unref(tmpdef);
f530d9ce JD	268	end:
f530d9ce JD	269	float_unlock();
c5e74408	270	return ret;
de0ba614	271	}
6dc2ca62	272
d11e9c49	273	void __attribute__((constructor)) ctf_float_init(void)
de0ba614	274	{
f72803ca MD	275	static_float_declaration =
	276	float_declaration_new(FLT_MANT_DIG,
	277	sizeof(float) * CHAR_BIT - FLT_MANT_DIG,
	278	BYTE_ORDER,
	279	__alignof__(float));
	280	static_double_declaration =
	281	float_declaration_new(DBL_MANT_DIG,
	282	sizeof(double) * CHAR_BIT - DBL_MANT_DIG,
11d43b90	283	BYTE_ORDER,
f72803ca	284	__alignof__(double));
de0ba614 MD	285	}
de0ba614 MD	286
d11e9c49	287	void __attribute__((destructor)) ctf_float_fini(void)
de0ba614	288	{
f72803ca MD	289	declaration_unref(&static_float_declaration->p);
f72803ca MD	290	declaration_unref(&static_double_declaration->p);
6dc2ca62	291	}