source: vbox/trunk/src/VBox/Additions/x11/x11include/xorg-server-1.5.3/fastblt.h@ 17448

/*

Copyright 1989, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from The Open Group.

*/

/*
 * Fast bitblt macros for certain hardware.  If your machine has an addressing
 * mode of small constant + register, you'll probably want this magic specific
 * code.  It's 25% faster for the R2000.  I haven't studied the Sparc
 * instruction set, but I suspect it also has this addressing mode.  Also,
 * unrolling the loop by 32 is possibly excessive for mfb. The number of times
 * the loop is actually looped through is pretty small.
 */

/*
 * WARNING:  These macros make *a lot* of assumptions about
 * the environment they are invoked in.  Plenty of implicit
 * arguments, lots of side effects.  Don't use them casually.
 */

#define SwitchOdd(n) case n: BodyOdd(n)
#define SwitchEven(n) case n: BodyEven(n)

/* to allow mfb and cfb to share code... */
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif

#ifndef BitRight
#define BitRight(a,b) SCRRIGHT(a,b)
#define BitLeft(a,b) SCRLEFT(a,b)
#endif

#ifdef LARGE_INSTRUCTION_CACHE
#define UNROLL 8
#define PackedLoop \
    switch (nl & (UNROLL-1)) { \
    SwitchOdd( 7) SwitchEven( 6) SwitchOdd( 5) SwitchEven( 4) \
    SwitchOdd( 3) SwitchEven( 2) SwitchOdd( 1) \
    } \
    while ((nl -= UNROLL) >= 0) { \
        LoopReset \
        BodyEven( 8) \
        BodyOdd( 7) BodyEven( 6) BodyOdd( 5) BodyEven( 4) \
        BodyOdd( 3) BodyEven( 2) BodyOdd( 1) \
    }
#else
#define UNROLL 4
#define PackedLoop \
    switch (nl & (UNROLL-1)) { \
    SwitchOdd( 3) SwitchEven( 2) SwitchOdd( 1) \
    } \
    while ((nl -= UNROLL) >= 0) { \
        LoopReset \
        BodyEven( 4) \
        BodyOdd( 3) BodyEven( 2) BodyOdd( 1) \
    }
#endif

#define DuffL(counter,label,body) \
    switch (counter & 3) { \
    label: \
        body \
    case 3: \
        body \
    case 2: \
        body \
    case 1: \
        body \
    case 0: \
        if ((counter -= 4) >= 0) \
            goto label; \
    }