NetBSD/sys/dev/rasops/rasops_masks.h

96 lines
3.5 KiB
C

/* $NetBSD: rasops_masks.h,v 1.9 2019/08/10 01:24:17 rin Exp $ */
/*-
* Copyright (c) 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _RASOPS_MASKS_H_
#define _RASOPS_MASKS_H_ 1
#include <sys/types.h>
#include <machine/endian.h>
/*
* Convenience macros. To get around the problem of dealing with properly
* ordered bits on little-endian machines, we just convert everything to
* big-endian and back again when we're done.
*
* MBL: move bits left
* MBR: move bits right
* MBE: make big-endian
*/
#if BYTE_ORDER == BIG_ENDIAN
#define MBL(x,y) ((y) > 31 ? 0 : (x) << (y))
#define MBR(x,y) ((y) > 31 ? 0 : (x) >> (y))
#define MBE(x) (x)
#else
#define MBL(x,y) ((y) > 31 ? 0 : MBE(MBE(x) << (y)))
#define MBR(x,y) ((y) > 31 ? 0 : MBE(MBE(x) >> (y)))
#define MBE(x) ( (((x) & 0x000000FFU) << 24) \
| (((x) & 0x0000FF00U) << 8) \
| (((x) & 0x00FF0000U) >> 8) \
| (((x) & 0xFF000000U) >> 24) )
#endif
/*
* Using GETBITS() and PUTBITS() inside a loop mightn't be such a good idea.
* There's probably some CSE and strength-reduction that the compiler won't
* even think about - really should have a few assumptions/separate cases.
*/
/* Get a number of bits ( <= 32 ) from *sp and store in dw */
#define GETBITS(sp, x, w, dw) do { \
dw = MBL(*(sp), (x)); \
if (((x) + (w)) > 32) \
dw |= (MBR((sp)[1], 32 - (x))); \
} while (0 /* CONSTCOND */)
/* Put a number of bits ( <= 32 ) from sw to *dp */
#define PUTBITS(sw, x, w, dp) do { \
int n = (x) + (w) - 32; \
if (n <= 0) { \
uint32_t mask = rasops_pmask[(x) & 31][(w) & 31]; \
*(dp) = (*(dp) & ~mask) | (MBR(sw, x) & mask); \
} else { \
*(dp) = (*(dp) & rasops_rmask[x]) | (MBR(sw, x)); \
(dp)[1] = ((dp)[1] & rasops_rmask[n]) | \
(MBL(sw, 32-(x)) & rasops_lmask[n]); \
} \
} while (0 /* CONSTCOND */)
/* rasops_masks.c */
extern const uint32_t rasops_lmask[32 + 1];
extern const uint32_t rasops_rmask[32 + 1];
extern const uint32_t rasops_pmask[32][32];
#endif /* _RASOPS_MASKS_H_ */