bitswap.h File Reference

Detailed Description

Functions for doing a rotation of bits/bytes used by parallel output.

Definition in file bitswap.h.

#include "FastLED.h"
#include "force_inline.h"

Go to the source code of this file.

Classes
union	just8bits
	Structure representing 8 bits of access. More...
struct	sub4
	Structure representing 32 bits of access. More...
union	bitswap_type
	Union containing a full 8 bytes to swap the bit orientation on. More...

Macros
#define	SWAPSA(X, N)
	Set out.X bits 0, 1, 2, and 3 to bit N of in.a.a, in.a.b, in.a.b, in.a.c, and in.a.d
#define	SWAPSB(X, N)
	Set out.X bits 0, 1, 2, and 3 to bit N of in.b.a, in.b.b, in.b.b, in.b.c, and in.b.d
#define	SWAPS(X, N)
	Set out.X bits to bit N of both in.a and in.b in order.

Functions
FASTLED_FORCE_INLINE void	swapbits8 (bitswap_type in, bitswap_type &out)
	Do an 8-byte by 8-bit rotation.
FASTLED_FORCE_INLINE void	slowswap (unsigned char *A, unsigned char *B)
	Slow version of the 8 byte by 8 bit rotation.
void	transpose8x1_noinline (unsigned char *A, unsigned char *B)
	Simplified form of bits rotating function.
FASTLED_FORCE_INLINE void	transpose8x1 (unsigned char *A, unsigned char *B)
	Simplified form of bits rotating function.
FASTLED_FORCE_INLINE void	transpose8x1_MSB (unsigned char *A, unsigned char *B)
	Simplified form of bits rotating function.
template<int m, int n>
FASTLED_FORCE_INLINE void	transpose8 (unsigned char *A, unsigned char *B)
	Templated bit-rotating function.

Macro Definition Documentation

SWAPS

#define SWAPS	(		X,
			N )

Value:

  out.  X ## 0 = in.a.a ## N; \
  out.  X ## 1 = in.a.b ## N; \
  out.  X ## 2 = in.a.c ## N; \
  out.  X ## 3 = in.a.d ## N; \
  out.  X ## 4 = in.b.a ## N; \
  out.  X ## 5 = in.b.b ## N; \
  out.  X ## 6 = in.b.c ## N; \
  out.  X ## 7 = in.b.d ## N;

Set out.X bits to bit N of both in.a and in.b in order.

Parameters

X	the sub4 of out to set
N	the bit of each byte to retrieve

See also

bitswap_type

Definition at line 101 of file bitswap.h.

SWAPSA

#define SWAPSA	(		X,
			N )

Value:

  out.  X ## 0 = in.a.a ## N; \
  out.  X ## 1 = in.a.b ## N; \
  out.  X ## 2 = in.a.c ## N; \
  out.  X ## 3 = in.a.d ## N;

Set out.X bits 0, 1, 2, and 3 to bit N of in.a.a, in.a.b, in.a.b, in.a.c, and in.a.d

Parameters

X	the sub4 of out to set
N	the bit of each byte to retrieve

See also

bitswap_type

Definition at line 81 of file bitswap.h.

SWAPSB

#define SWAPSB	(		X,
			N )

Value:

  out.  X ## 0 = in.b.a ## N; \
  out.  X ## 1 = in.b.b ## N; \
  out.  X ## 2 = in.b.c ## N; \
  out.  X ## 3 = in.b.d ## N;

Set out.X bits 0, 1, 2, and 3 to bit N of in.b.a, in.b.b, in.b.b, in.b.c, and in.b.d

Parameters

X	the sub4 of out to set
N	the bit of each byte to retrieve

See also

bitswap_type

Definition at line 91 of file bitswap.h.

Function Documentation

slowswap()

FASTLED_FORCE_INLINE void slowswap	(	unsigned char *	A,
		unsigned char *	B )

Slow version of the 8 byte by 8 bit rotation.

Definition at line 160 of file bitswap.h.

swapbits8()

FASTLED_FORCE_INLINE void swapbits8	(	bitswap_type	in,
		bitswap_type &	out )

Do an 8-byte by 8-bit rotation.

Definition at line 112 of file bitswap.h.

transpose8()

template<int m, int n>

FASTLED_FORCE_INLINE void transpose8	(	unsigned char *	A,
		unsigned char *	B )

Templated bit-rotating function.

Based on code found here: https://web.archive.org/web/20190108225554/http://www.hackersdelight.org/hdcodetxt/transpose8.c.txt

Definition at line 251 of file bitswap.h.

transpose8x1()

FASTLED_FORCE_INLINE void transpose8x1	(	unsigned char *	A,
		unsigned char *	B )

Simplified form of bits rotating function.

This rotates data into LSB for a faster write (the code using this data can happily walk the array backwards).
Based on code found here: https://web.archive.org/web/20190108225554/http://www.hackersdelight.org/hdcodetxt/transpose8.c.txt

Definition at line 191 of file bitswap.h.

transpose8x1_MSB()

FASTLED_FORCE_INLINE void transpose8x1_MSB	(	unsigned char *	A,
		unsigned char *	B )

Simplified form of bits rotating function.

Based on code found here: https://web.archive.org/web/20190108225554/http://www.hackersdelight.org/hdcodetxt/transpose8.c.txt

Definition at line 217 of file bitswap.h.

transpose8x1_noinline()

void transpose8x1_noinline	(	unsigned char *	A,
		unsigned char *	B )

Simplified form of bits rotating function.

This rotates data into LSB for a faster write (the code using this data can happily walk the array backwards).
Based on code found here: https://web.archive.org/web/20190108225554/http://www.hackersdelight.org/hdcodetxt/transpose8.c.txt

Definition at line 4 of file transpose8x1_noinline.cpp.