Utility Library

Collaboration diagram for Utility Library:

Modules

 Assembler Support
 Assertions
 Atomic Operations
 Bit Operations
 Byte Order Conversion
 Compiler Support
 Data in Huge Data Memory Space
 Data in Program Space
 Standard integer types
 String Operations
 Unaligned Access Helpers

Defines

#define xstr(s)   str(s)
 Stringify the result after expansion of a macro argument.
#define str(s)   #s
 Stringify a macro argument without expansion.
#define ARRAY_LEN(a)   (sizeof(a) / sizeof((a)[0]))
 Get the number of elements in array a.
#define container_of(ptr, type, member)   ((type *)((uintptr_t)(ptr) - offsetof(type, member)))
 Get the containing object.
#define round_down(x, order)
 Round down to the nearest power of two boundary.
#define round_up(x, order)
 Round up to the nearest power of two boundary.
#define div_ceil(a, b)   (((a) + (b) - 1) / (b))
 Calculate $ \left\lceil \frac{a}{b} \right\rceil $ using integer arithmetic.

Functions

static int isdigit (int c)
 Determine whether or not the character c is a digit.
static int iscntrl (int c)
 Determine whether or not the character c is a control character.
static int isspace (int c)
 Determine whether or not the character c is a space.
int_fast8_t ilog2_undefined (void)
static __always_inline int_fast8_t ilog2 (uint32_t x)
 Calculate the base-2 logarithm of a number rounded down to the nearest integer.
static __always_inline bool is_power_of_two (unsigned long x)
 Test if a given value is a power of two.
static unsigned long word_align (unsigned long x)
 Round up to the nearest word-aligned boundary.

Minimum and Maximum



#define min_s(a, b)
 Get the lowest of two signed values.
#define min_u(a, b)
 Get the lowest of two unsigned values.
#define max_s(a, b)
 Get the highest of two signed values.
#define max_u(a, b)
 Get the highest of two unsigned values.

Detailed Description

This is a collection of utility functions and macros which may be useful when dealing with certain common problems, e.g. accessing data from a byte stream, simple mathematical operations, etc.

Define Documentation

#define ARRAY_LEN ( a   )     (sizeof(a) / sizeof((a)[0]))

Get the number of elements in array a.

Definition at line 68 of file util.h.

Referenced by membag_alloc(), membag_free(), membag_get_largest_free_block_size(), membag_get_smallest_free_block_size(), membag_get_total(), and membag_init().

#define container_of ( ptr,
type,
member   )     ((type *)((uintptr_t)(ptr) - offsetof(type, member)))

Get the containing object.

Parameters:
ptr Pointer to the contained object.
type Type of the containing object.
member Member name of the contained object inside the containing object.
Returns:
Pointer to the containing object.

Definition at line 120 of file util.h.

Referenced by spi_master_polled_of(), spi_poll(), string_stream_of(), and touch_calibrate_task_handler().

#define div_ceil ( a,
b   )     (((a) + (b) - 1) / (b))

Calculate $ \left\lceil \frac{a}{b} \right\rceil $ using integer arithmetic.

Parameters:
a An integer
b Another integer
Returns:
(a / b) rounded up to the nearest integer.

Definition at line 335 of file util.h.

Referenced by bit_array_find_first_one_bit().

#define max_s ( a,
b   ) 
Value:
((sizeof(a) == 1) && (sizeof(b) == 1) ? compiler_max_s8(a, b)   \
        : (sizeof(a) <= 2) && (sizeof(b) <= 2) ? compiler_max_s16(a, b) \
        : (sizeof(a) <= 4) && (sizeof(b) <= 4) ? compiler_max_s32(a, b) \
        : compiler_max_s64(a, b))

Get the highest of two signed values.

Parameters:
a A signed integer
b Another signed integer
Returns:
The numerically highest value of a and b.

Definition at line 156 of file util.h.

Referenced by wtk_check_box_size_hint(), and wtk_radio_button_size_hint().

#define max_u ( a,
b   ) 
Value:
((sizeof(a) == 1) && (sizeof(b) == 1) ? compiler_max_u8(a, b)   \
        : (sizeof(a) <= 2) && (sizeof(b) <= 2) ? compiler_max_u16(a, b) \
        : (sizeof(a) <= 4) && (sizeof(b) <= 4) ? compiler_max_u32(a, b) \
        : compiler_max_u64(a, b))

Get the highest of two unsigned values.

Parameters:
a An unsigned integer
b Another unsigned integer
Returns:
The numerically highest value of a and b.

Definition at line 168 of file util.h.

#define min_s ( a,
b   ) 
Value:
((sizeof(a) == 1) && (sizeof(b) == 1) ? compiler_min_s8(a, b)   \
        : (sizeof(a) <= 2) && (sizeof(b) <= 2) ? compiler_min_s16(a, b) \
        : (sizeof(a) <= 4) && (sizeof(b) <= 4) ? compiler_min_s32(a, b) \
        : compiler_min_s64(a, b))

Get the lowest of two signed values.

Parameters:
a A signed integer
b Another signed integer
Returns:
The numerically lowest value of a and b.

Definition at line 132 of file util.h.

#define min_u ( a,
b   ) 
Value:
((sizeof(a) == 1) && (sizeof(b) == 1) ? compiler_min_u8(a, b)   \
        : (sizeof(a) <= 2) && (sizeof(b) <= 2) ? compiler_min_u16(a, b) \
        : (sizeof(a) <= 4) && (sizeof(b) <= 4) ? compiler_min_u32(a, b) \
        : compiler_min_u64(a, b))

Get the lowest of two unsigned values.

Parameters:
a An unsigned integer
b Another unsigned integer
Returns:
The numerically lowest value of a and b.

Definition at line 144 of file util.h.

Referenced by stream_priv_write().

#define round_down ( x,
order   ) 
Value:
(sizeof(x) == 4 ? round_down32((uint32_t)(x), (order)) :        \
                 sizeof(x) == 2 ? round_down16((uint16_t)(x), (order)) :        \
                 sizeof(x) == 1 ? round_down8 (( uint8_t)(x), (order)) :        \
                (priv_round_down_bad_type(),1))

Round down to the nearest power of two boundary.

Parameters:
x A positive integer
order log2 of the required boundary.
Returns:
x rounded down to the nearest multiple of (1 << order)

Definition at line 250 of file util.h.

Referenced by physmem_alloc().

#define round_up ( x,
order   ) 
Value:
(sizeof(x) == 4 ? round_up32((uint32_t)(x), (order)) :  \
                 sizeof(x) == 2 ? round_up16((uint16_t)(x), (order)) :  \
                 sizeof(x) == 1 ? round_up8 (( uint8_t)(x), (order)) :  \
                (priv_round_up_bad_type(),1))

Round up to the nearest power of two boundary.

Parameters:
x A positive integer
order log2 of the required boundary.
Returns:
x rounded up to the next multiple of (1 << order)

Definition at line 280 of file util.h.

Referenced by membag_pool_init_physmem(), physmem_alloc_low(), and word_align().

#define str ( s   )     #s

Stringify a macro argument without expansion.

Definition at line 63 of file util.h.

#define xstr ( s   )     str(s)

Stringify the result after expansion of a macro argument.

Definition at line 58 of file util.h.

Function Documentation

static __always_inline int_fast8_t ilog2 ( uint32_t  x  )  [static]

Calculate the base-2 logarithm of a number rounded down to the nearest integer.

Parameters:
x A 32-bit value
Returns:
The base-2 logarithm of x, or -1 if x is 0.

Definition at line 190 of file util.h.

References compiler_clz, ilog2_undefined(), and is_constant.

Referenced by board_enable_sdram(), and tsfs_read().

int_fast8_t ilog2_undefined ( void   ) 

For internal use only.

Undefined function. Will cause a link failure if ilog2() is called with an invalid constant value.

Referenced by ilog2().

static __always_inline bool is_power_of_two ( unsigned long  x  )  [static]

Test if a given value is a power of two.

Parameters:
x The value to test
Returns:
true if x is a power of two, false otherwise

Definition at line 236 of file util.h.

static int iscntrl ( int  c  )  [inline, static]

Determine whether or not the character c is a control character.

Parameters:
c The character to consider.
Return values:
0 The character c is not a control character.
1 The character c is a control character.

Definition at line 90 of file util.h.

static int isdigit ( int  c  )  [inline, static]

Determine whether or not the character c is a digit.

Parameters:
c The character to consider.
Return values:
0 The character c is not a digit.
1 The character c is a digit.

Definition at line 77 of file util.h.

static int isspace ( int  c  )  [inline, static]

Determine whether or not the character c is a space.

Note:
This implementation is very limited in that it doesn't consider a bunch of control characters that probably should be interpreted as space.
Parameters:
c The character to consider.
Return values:
0 The character c is not a space.
1 The character c is a space.

Definition at line 106 of file util.h.

static unsigned long word_align ( unsigned long  x  )  [inline, static]

Round up to the nearest word-aligned boundary.

Parameters:
x Address or offset to be word-aligned
Returns:
The smallest number y where y >= x and y & 3 == 0.

Definition at line 307 of file util.h.

References round_up.

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