Saturating scalar helpers for Q11 and Q16 values. More...

Macros
#define	SGL_Q11_FRAC_BITS (11U)
	Number of fractional bits in a Q11 value.

#define	SGL_Q11_ONE (2048)
	Q11 representation of 1.0 (`1 << 11`).

#define	SGL_Q11_HALF (1024)
	Q11 representation of 0.5.

#define	SGL_Q11_MASK (2047U)
	Mask selecting all eleven Q11 fractional bits.

#define	SGL_Q16_FRAC_BITS (16U)
	Number of fractional bits in a Q16 value.

#define	SGL_Q16_ONE (65536)
	Q16 representation of 1.0 (`1 << 16`).

#define	SGL_Q16_HALF (32768)
	Q16 representation of 0.5.

#define	SGL_Q16_MASK (65535U)
	Mask selecting all sixteen Q16 fractional bits.

#define	SGL_FIXED_I64_BITS (64U)
	Bit width used by the portable signed-division helpers.

#define	SGL_FIXED_INT32_MAX (2147483647)
	Maximum signed 32-bit value without standard-library constants.

#define	SGL_FIXED_INT32_MIN (-2147483647 - 1)
	Minimum signed 32-bit value without standard-library constants.

#define	SGL_FIXED_INT16_MAX (32767)
	Maximum signed 16-bit value without standard-library constants.

#define	SGL_FIXED_INT16_MIN (-32767 - 1)
	Minimum signed 16-bit value without standard-library constants.

Typedefs
typedef sgl_int16_t	sgl_q11_t
	Signed Q11 value stored in 16 bits.

typedef sgl_int32_t	sgl_q11_ext_t
	Extended signed Q11 value stored in 32 bits.

typedef sgl_int32_t	sgl_q16_t
	Signed Q16 value stored in 32 bits.

typedef sgl_int64_t	sgl_q16_ext_t
	Extended signed Q16 value stored in 64 bits.

typedef int16x8_t	sgl_simd_q11_t
	Eight signed 16-bit Q11 lanes.

typedef int32x4_t	sgl_simd_q11_ext_t
	Four signed 32-bit extended Q11 lanes.

Functions
static sgl_int32_t	sgl_fixed_clamp_i64_to_i32 (sgl_int64_t value)
	Saturates a signed 64-bit value to the signed 32-bit range.

static sgl_int16_t	sgl_fixed_clamp_i32_to_i16 (sgl_int32_t value)
	Saturates a signed 32-bit value to the signed 16-bit range.

static sgl_int64_t	sgl_fixed_div_pow2_i64 (sgl_int64_t value, sgl_uint32_t shift)
	Divides by a power of two with C99 signed-division semantics.

static sgl_int64_t	sgl_fixed_floor_pow2_i64 (sgl_int64_t value, sgl_uint32_t shift)
	Divides by a power of two while rounding toward negative infinity.

static sgl_q11_ext_t	sgl_int_to_q11 (sgl_q11_ext_t value)
	Converts an integer to extended Q11 with saturation.

static sgl_q11_ext_t	sgl_q11_get_int_part (sgl_q11_ext_t value)
	Extracts the integer part of an extended Q11 value.

static sgl_q11_ext_t	sgl_q11_get_frac_part (sgl_q11_ext_t value)
	Extracts the signed fractional part of an extended Q11 value.

static sgl_q11_ext_t	sgl_q11_round_up (sgl_q11_ext_t value)
	Adds the Q11 half-unit used before rounded conversion.

static sgl_q11_ext_t	sgl_q11_shift_down (sgl_q11_ext_t value)
	Removes Q11 fractional bits while rounding toward negative infinity.

static sgl_q11_t	sgl_q11_mul (sgl_q11_t a, sgl_q11_t b)
	Multiplies two Q11 values with rounding and saturation.

static sgl_q11_ext_t	sgl_q11_ext_mul (sgl_q11_ext_t a, sgl_q11_ext_t b)
	Multiplies two extended Q11 values with rounding and saturation.

static sgl_q16_ext_t	sgl_int_to_q16 (sgl_int32_t value)
	Converts a signed 32-bit integer to extended Q16.

static sgl_int32_t	sgl_q16_round_to_int32 (sgl_q16_ext_t value)
	Rounds an extended Q16 value to the nearest signed 32-bit integer.

static sgl_uint8_t	sgl_clamp_u8_i32 (sgl_int32_t val)
	Saturates a signed 32-bit channel value to 0 through 255.

static sgl_simd_q11_t	sgl_simd_q11_mul (sgl_simd_q11_t a, sgl_simd_q11_t b)
	Multiplies eight Q11 lane pairs with rounding and saturation.

static sgl_simd_q11_ext_t	sgl_simd_q11_ext_mul (sgl_simd_q11_ext_t a, sgl_simd_q11_ext_t b)
	Multiplies four extended Q11 lane pairs.

static uint8x8_t	sgl_simd_clamp_u8_i32 (int32x4_t lo, int32x4_t hi)
	Saturates eight signed 32-bit channel lanes to unsigned bytes.

Detailed Description

Saturating scalar helpers for Q11 and Q16 values.

Function Documentation

◆ sgl_clamp_u8_i32()

static sgl_uint8_t sgl_clamp_u8_i32 ( sgl_int32_t val )

inlinestatic

Saturates a signed 32-bit channel value to 0 through 255.

Parameters

[in] val Channel value.

Returns: Saturated unsigned byte.

Definition at line 364 of file generic.h.

◆ sgl_fixed_clamp_i32_to_i16()

static sgl_int16_t sgl_fixed_clamp_i32_to_i16 ( sgl_int32_t value )

inlinestatic

Saturates a signed 32-bit value to the signed 16-bit range.

Parameters

[in] value Value to clamp.

Returns: Saturated signed 16-bit value.

Definition at line 80 of file generic.h.

References SGL_FIXED_INT16_MAX, and SGL_FIXED_INT16_MIN.

Referenced by sgl_q11_mul().

◆ sgl_fixed_clamp_i64_to_i32()

static sgl_int32_t sgl_fixed_clamp_i64_to_i32 ( sgl_int64_t value )

inlinestatic

Saturates a signed 64-bit value to the signed 32-bit range.

Parameters

[in] value Value to clamp.

Returns: Saturated signed 32-bit value.

Definition at line 57 of file generic.h.

References SGL_FIXED_INT32_MAX, and SGL_FIXED_INT32_MIN.

Referenced by sgl_int_to_q11(), sgl_q11_ext_mul(), and sgl_q11_round_up().

◆ sgl_fixed_div_pow2_i64()

static sgl_int64_t sgl_fixed_div_pow2_i64	(	sgl_int64_t	value,
		sgl_uint32_t	shift
	)

inlinestatic

Divides by a power of two with C99 signed-division semantics.

Parameters

[in]	value	Dividend.
[in]	shift	Base-two exponent in the range 0 through 63.

Returns: value / (1 << shift), truncated toward zero, or 0 when shift is outside the supported range.

The shift is applied only to an unsigned magnitude, avoiding an implementation-defined right shift of a negative signed integer.

Definition at line 108 of file generic.h.

References SGL_FIXED_I64_BITS.

Referenced by sgl_q11_get_int_part().

◆ sgl_fixed_floor_pow2_i64()

static sgl_int64_t sgl_fixed_floor_pow2_i64	(	sgl_int64_t	value,
		sgl_uint32_t	shift
	)

inlinestatic

Divides by a power of two while rounding toward negative infinity.

Parameters

[in]	value	Dividend.
[in]	shift	Base-two exponent.

Returns: Portable equivalent of an arithmetic signed right shift.

Definition at line 139 of file generic.h.

References SGL_FIXED_I64_BITS.

Referenced by sgl_q11_ext_mul().

◆ sgl_int_to_q11()

static sgl_q11_ext_t sgl_int_to_q11 ( sgl_q11_ext_t value )

inlinestatic

Converts an integer to extended Q11 with saturation.

Parameters

[in] value Integer value.

Returns: Q11 value equal to value * 2048, saturated to 32 bits.

Definition at line 177 of file generic.h.

References sgl_fixed_clamp_i64_to_i32(), and SGL_Q11_ONE.

◆ sgl_int_to_q16()

static sgl_q16_ext_t sgl_int_to_q16 ( sgl_int32_t value )

inlinestatic

Converts a signed 32-bit integer to extended Q16.

Parameters

[in] value Integer value.

Returns: Exact 64-bit Q16 representation.

Definition at line 311 of file generic.h.

References SGL_Q16_ONE.

◆ sgl_q11_ext_mul()

static sgl_q11_ext_t sgl_q11_ext_mul	(	sgl_q11_ext_t	a,
		sgl_q11_ext_t	b
	)

inlinestatic

Multiplies two extended Q11 values with rounding and saturation.

Parameters

[in]	a	First Q11 factor.
[in]	b	Second Q11 factor.

Returns: Saturated extended Q11 product.

Definition at line 291 of file generic.h.

References sgl_fixed_clamp_i64_to_i32(), sgl_fixed_floor_pow2_i64(), SGL_Q11_FRAC_BITS, and SGL_Q11_HALF.

◆ sgl_q11_get_frac_part()

static sgl_q11_ext_t sgl_q11_get_frac_part ( sgl_q11_ext_t value )

inlinestatic

Extracts the signed fractional part of an extended Q11 value.

Parameters

[in] value Extended Q11 value.

Returns: Fractional numerator in the range -2047 through 2047.

Definition at line 209 of file generic.h.

References sgl_q11_get_int_part(), and SGL_Q11_ONE.

◆ sgl_q11_get_int_part()

static sgl_q11_ext_t sgl_q11_get_int_part ( sgl_q11_ext_t value )

inlinestatic

Extracts the integer part of an extended Q11 value.

Parameters

[in] value Extended Q11 value.

Returns: Integer part truncated toward zero.

Definition at line 193 of file generic.h.

References sgl_fixed_div_pow2_i64(), and SGL_Q11_FRAC_BITS.

Referenced by sgl_q11_get_frac_part().

◆ sgl_q11_mul()

static sgl_q11_t sgl_q11_mul	(	sgl_q11_t	a,
		sgl_q11_t	b
	)

inlinestatic

Multiplies two Q11 values with rounding and saturation.

Parameters

[in]	a	First Q11 factor.
[in]	b	Second Q11 factor.

Returns: Saturated Q11 product.

Definition at line 270 of file generic.h.

References sgl_fixed_clamp_i32_to_i16(), sgl_q11_round_up(), and sgl_q11_shift_down().

◆ sgl_q11_round_up()

static sgl_q11_ext_t sgl_q11_round_up ( sgl_q11_ext_t value )

inlinestatic

Adds the Q11 half-unit used before rounded conversion.

Parameters

[in] value Extended Q11 value.

Returns: value + 1024, saturated to signed 32 bits.

Definition at line 225 of file generic.h.

References sgl_fixed_clamp_i64_to_i32(), and SGL_Q11_HALF.

Referenced by sgl_q11_mul().

◆ sgl_q11_shift_down()

static sgl_q11_ext_t sgl_q11_shift_down ( sgl_q11_ext_t value )

inlinestatic

Removes Q11 fractional bits while rounding toward negative infinity.

Parameters

[in] value Extended Q11 value.

Returns: Integer result of a portable arithmetic 11-bit right shift.

Definition at line 241 of file generic.h.

References SGL_Q11_FRAC_BITS, and SGL_Q11_MASK.

Referenced by sgl_q11_mul().

◆ sgl_q16_round_to_int32()

static sgl_int32_t sgl_q16_round_to_int32 ( sgl_q16_ext_t value )

inlinestatic

Rounds an extended Q16 value to the nearest signed 32-bit integer.

Parameters

[in] value Extended Q16 value.

Returns: Rounded and saturated integer.

Definition at line 325 of file generic.h.

References SGL_FIXED_INT32_MAX, SGL_FIXED_INT32_MIN, SGL_Q16_FRAC_BITS, and SGL_Q16_HALF.

◆ sgl_simd_clamp_u8_i32()

static uint8x8_t sgl_simd_clamp_u8_i32	(	int32x4_t	lo,
		int32x4_t	hi
	)

inlinestatic

Saturates eight signed 32-bit channel lanes to unsigned bytes.

Parameters

[in]	lo	First four signed channel values.
[in]	hi	Last four signed channel values.

Returns: Eight values saturated to the range 0 through 255.

Definition at line 87 of file neon.h.

◆ sgl_simd_q11_ext_mul()

static sgl_simd_q11_ext_t sgl_simd_q11_ext_mul	(	sgl_simd_q11_ext_t	a,
		sgl_simd_q11_ext_t	b
	)

inlinestatic

Multiplies four extended Q11 lane pairs.

Parameters

[in]	a	First extended Q11 vector.
[in]	b	Second extended Q11 vector.

Returns: Rounded and saturated extended Q11 products.

Each 32-bit lane stores one Q11 value. Multiplication creates a Q22 intermediate, then a rounding right shift restores the Q11 scale.

Definition at line 60 of file neon.h.

References SGL_Q11_FRAC_BITS.

◆ sgl_simd_q11_mul()

static sgl_simd_q11_t sgl_simd_q11_mul	(	sgl_simd_q11_t	a,
		sgl_simd_q11_t	b
	)

inlinestatic

Multiplies eight Q11 lane pairs with rounding and saturation.

Parameters

[in]	a	First Q11 vector.
[in]	b	Second Q11 vector.

Returns: Q11 vector equivalent to (a * b) >> 11 per lane.

Definition at line 28 of file neon.h.

References SGL_Q11_FRAC_BITS.

Macros

Typedefs

Functions

Detailed Description

Function Documentation

◆ sgl_clamp_u8_i32()

◆ sgl_fixed_clamp_i32_to_i16()

◆ sgl_fixed_clamp_i64_to_i32()

◆ sgl_fixed_div_pow2_i64()

◆ sgl_fixed_floor_pow2_i64()

◆ sgl_int_to_q11()

◆ sgl_int_to_q16()

◆ sgl_q11_ext_mul()

◆ sgl_q11_get_frac_part()

◆ sgl_q11_get_int_part()

◆ sgl_q11_mul()

◆ sgl_q11_round_up()

◆ sgl_q11_shift_down()

◆ sgl_q16_round_to_int32()

◆ sgl_simd_clamp_u8_i32()

◆ sgl_simd_q11_ext_mul()

◆ sgl_simd_q11_mul()