Move to kernel style SPDX license identifiers

[babeltrace.git] / src / lib / trace-ir / utils.h

/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
 */

#ifndef BABELTRACE_TRACE_IR_UTILS_INTERNAL_H
#define BABELTRACE_TRACE_IR_UTILS_INTERNAL_H

#include "common/macros.h"
#include <babeltrace2/trace-ir/field-class.h>
#include <stdbool.h>
#include <stdint.h>

#include "clock-class.h"

struct search_query {
	gpointer value;
	int found;
};

static inline
uint64_t bt_util_ns_from_value(uint64_t frequency, uint64_t value_cycles)
{
	uint64_t ns;

	if (frequency == UINT64_C(1000000000)) {
		ns = value_cycles;
	} else {
		double dblres = ((1e9 * (double) value_cycles) / (double) frequency);

		if (dblres >= (double) UINT64_MAX) {
			/* Overflows uint64_t */
			ns = UINT64_C(-1);
		} else {
			ns = (uint64_t) dblres;
		}
	}

	return ns;
}

static inline
bool bt_util_get_base_offset_ns(int64_t offset_seconds, uint64_t offset_cycles,
		uint64_t frequency, int64_t *base_offset_ns)
{
	bool overflows = false;
	uint64_t offset_cycles_ns;

	BT_ASSERT_DBG(base_offset_ns);

	/* Initialize nanosecond timestamp to clock's offset in seconds */
	if (offset_seconds <= (INT64_MIN / INT64_C(1000000000) - 1) ||
			offset_seconds >= (INT64_MAX / INT64_C(1000000000)) - 1) {
		/*
		 * Overflow: offset in seconds converted to nanoseconds
		 * is outside the int64_t range. We also subtract 1 here
		 * to leave "space" for the offset in cycles converted
		 * to nanoseconds (which is always less than 1 second by
		 * contract).
		 */
		overflows = true;
		goto end;
	}

	/* Offset (seconds) to nanoseconds */
	*base_offset_ns = offset_seconds * INT64_C(1000000000);

	/* Add offset in cycles */
	BT_ASSERT_DBG(offset_cycles < frequency);
	offset_cycles_ns = bt_util_ns_from_value(frequency,
		offset_cycles);
	BT_ASSERT_DBG(offset_cycles_ns < 1000000000);
	*base_offset_ns += (int64_t) offset_cycles_ns;

end:
	return overflows;
}

static inline
int bt_util_ns_from_origin_inline(int64_t base_offset_ns,
		int64_t offset_seconds, uint64_t offset_cycles,
		uint64_t frequency, uint64_t value, int64_t *ns_from_origin)
{
	int ret = 0;
	uint64_t value_ns_unsigned;
	int64_t value_ns_signed;

	/* Initialize to clock class's base offset */
	*ns_from_origin = base_offset_ns;

	/* Add given value in cycles */
	value_ns_unsigned = bt_util_ns_from_value(frequency, value);
	if (value_ns_unsigned >= (uint64_t) INT64_MAX) {
		/*
		 * FIXME: `value_ns_unsigned` could be greater than
		 * `INT64_MAX` in fact: in this case, we need to
		 * subtract `INT64_MAX` from `value_ns_unsigned`, make
		 * sure that the difference is less than `INT64_MAX`,
		 * and try to add them one after the other to
		 * `*ns_from_origin`.
		 */
		ret = -1;
		goto end;
	}

	value_ns_signed = (int64_t) value_ns_unsigned;
	BT_ASSERT_DBG(value_ns_signed >= 0);

	if (*ns_from_origin <= 0) {
		goto add_value;
	}

	if (value_ns_signed > INT64_MAX - *ns_from_origin) {
		ret = -1;
		goto end;
	}

add_value:
	*ns_from_origin += value_ns_signed;

end:
	return ret;
}

static inline
int bt_util_ns_from_origin_clock_class(const struct bt_clock_class *clock_class,
		uint64_t value, int64_t *ns_from_origin)
{
	int ret = 0;

	if (clock_class->base_offset.overflows) {
		ret = -1;
		goto end;
	}

	ret = bt_util_ns_from_origin_inline(clock_class->base_offset.value_ns,
		clock_class->offset_seconds, clock_class->offset_cycles,
		clock_class->frequency, value, ns_from_origin);

end:
	return ret;
}

static inline
bool bt_util_value_is_in_range_signed(uint64_t size, int64_t value)
{
	int64_t min_value = UINT64_C(-1) << (size - 1);
	int64_t max_value = (UINT64_C(1) << (size - 1)) - 1;
	return value >= min_value && value <= max_value;
}

static inline
bool bt_util_value_is_in_range_unsigned(unsigned int size, uint64_t value)
{
	uint64_t max_value = (size == 64) ? UINT64_MAX :
		(UINT64_C(1) << size) - 1;
	return value <= max_value;
}

#endif /* BABELTRACE_TRACE_IR_UTILS_INTERNAL_H */