linux/drivers/video/atafb_utils.h
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   1#ifndef _VIDEO_ATAFB_UTILS_H
   2#define _VIDEO_ATAFB_UTILS_H
   3
   4/* ================================================================= */
   5/*                      Utility Assembler Functions                  */
   6/* ================================================================= */
   7
   8/* ====================================================================== */
   9
  10/* Those of a delicate disposition might like to skip the next couple of
  11 * pages.
  12 *
  13 * These functions are drop in replacements for memmove and
  14 * memset(_, 0, _). However their five instances add at least a kilobyte
  15 * to the object file. You have been warned.
  16 *
  17 * Not a great fan of assembler for the sake of it, but I think
  18 * that these routines are at least 10 times faster than their C
  19 * equivalents for large blits, and that's important to the lowest level of
  20 * a graphics driver. Question is whether some scheme with the blitter
  21 * would be faster. I suspect not for simple text system - not much
  22 * asynchrony.
  23 *
  24 * Code is very simple, just gruesome expansion. Basic strategy is to
  25 * increase data moved/cleared at each step to 16 bytes to reduce
  26 * instruction per data move overhead. movem might be faster still
  27 * For more than 15 bytes, we try to align the write direction on a
  28 * longword boundary to get maximum speed. This is even more gruesome.
  29 * Unaligned read/write used requires 68020+ - think this is a problem?
  30 *
  31 * Sorry!
  32 */
  33
  34
  35/* ++roman: I've optimized Robert's original versions in some minor
  36 * aspects, e.g. moveq instead of movel, let gcc choose the registers,
  37 * use movem in some places...
  38 * For other modes than 1 plane, lots of more such assembler functions
  39 * were needed (e.g. the ones using movep or expanding color values).
  40 */
  41
  42/* ++andreas: more optimizations:
  43   subl #65536,d0 replaced by clrw d0; subql #1,d0 for dbcc
  44   addal is faster than addaw
  45   movep is rather expensive compared to ordinary move's
  46   some functions rewritten in C for clarity, no speed loss */
  47
  48static inline void *fb_memclear_small(void *s, size_t count)
  49{
  50        if (!count)
  51                return 0;
  52
  53        asm volatile ("\n"
  54                "       lsr.l   #1,%1 ; jcc 1f ; move.b %2,-(%0)\n"
  55                "1:     lsr.l   #1,%1 ; jcc 1f ; move.w %2,-(%0)\n"
  56                "1:     lsr.l   #1,%1 ; jcc 1f ; move.l %2,-(%0)\n"
  57                "1:     lsr.l   #1,%1 ; jcc 1f ; move.l %2,-(%0) ; move.l %2,-(%0)\n"
  58                "1:"
  59                : "=a" (s), "=d" (count)
  60                : "d" (0), "0" ((char *)s + count), "1" (count));
  61        asm volatile ("\n"
  62                "       subq.l  #1,%1\n"
  63                "       jcs     3f\n"
  64                "       move.l  %2,%%d4; move.l %2,%%d5; move.l %2,%%d6\n"
  65                "2:     movem.l %2/%%d4/%%d5/%%d6,-(%0)\n"
  66                "       dbra    %1,2b\n"
  67                "3:"
  68                : "=a" (s), "=d" (count)
  69                : "d" (0), "0" (s), "1" (count)
  70                : "d4", "d5", "d6"
  71                );
  72
  73        return 0;
  74}
  75
  76
  77static inline void *fb_memclear(void *s, size_t count)
  78{
  79        if (!count)
  80                return 0;
  81
  82        if (count < 16) {
  83                asm volatile ("\n"
  84                        "       lsr.l   #1,%1 ; jcc 1f ; clr.b (%0)+\n"
  85                        "1:     lsr.l   #1,%1 ; jcc 1f ; clr.w (%0)+\n"
  86                        "1:     lsr.l   #1,%1 ; jcc 1f ; clr.l (%0)+\n"
  87                        "1:     lsr.l   #1,%1 ; jcc 1f ; clr.l (%0)+ ; clr.l (%0)+\n"
  88                        "1:"
  89                        : "=a" (s), "=d" (count)
  90                        : "0" (s), "1" (count));
  91        } else {
  92                long tmp;
  93                asm volatile ("\n"
  94                        "       move.l  %1,%2\n"
  95                        "       lsr.l   #1,%2 ; jcc 1f ; clr.b (%0)+ ; subq.w #1,%1\n"
  96                        "       lsr.l   #1,%2 ; jcs 2f\n"  /* %0 increased=>bit 2 switched*/
  97                        "       clr.w   (%0)+  ; subq.w  #2,%1 ; jra 2f\n"
  98                        "1:     lsr.l   #1,%2 ; jcc 2f\n"
  99                        "       clr.w   (%0)+  ; subq.w  #2,%1\n"
 100                        "2:     move.w  %1,%2; lsr.l #2,%1 ; jeq 6f\n"
 101                        "       lsr.l   #1,%1 ; jcc 3f ; clr.l (%0)+\n"
 102                        "3:     lsr.l   #1,%1 ; jcc 4f ; clr.l (%0)+ ; clr.l (%0)+\n"
 103                        "4:     subq.l  #1,%1 ; jcs 6f\n"
 104                        "5:     clr.l   (%0)+; clr.l (%0)+ ; clr.l (%0)+ ; clr.l (%0)+\n"
 105                        "       dbra    %1,5b ; clr.w %1; subq.l #1,%1; jcc 5b\n"
 106                        "6:     move.w  %2,%1; btst #1,%1 ; jeq 7f ; clr.w (%0)+\n"
 107                        "7:     btst    #0,%1 ; jeq 8f ; clr.b (%0)+\n"
 108                        "8:"
 109                        : "=a" (s), "=d" (count), "=d" (tmp)
 110                        : "0" (s), "1" (count));
 111        }
 112
 113        return 0;
 114}
 115
 116
 117static inline void *fb_memset255(void *s, size_t count)
 118{
 119        if (!count)
 120                return 0;
 121
 122        asm volatile ("\n"
 123                "       lsr.l   #1,%1 ; jcc 1f ; move.b %2,-(%0)\n"
 124                "1:     lsr.l   #1,%1 ; jcc 1f ; move.w %2,-(%0)\n"
 125                "1:     lsr.l   #1,%1 ; jcc 1f ; move.l %2,-(%0)\n"
 126                "1:     lsr.l   #1,%1 ; jcc 1f ; move.l %2,-(%0) ; move.l %2,-(%0)\n"
 127                "1:"
 128                : "=a" (s), "=d" (count)
 129                : "d" (-1), "0" ((char *)s+count), "1" (count));
 130        asm volatile ("\n"
 131                "       subq.l  #1,%1 ; jcs 3f\n"
 132                "       move.l  %2,%%d4; move.l %2,%%d5; move.l %2,%%d6\n"
 133                "2:     movem.l %2/%%d4/%%d5/%%d6,-(%0)\n"
 134                "       dbra    %1,2b\n"
 135                "3:"
 136                : "=a" (s), "=d" (count)
 137                : "d" (-1), "0" (s), "1" (count)
 138                : "d4", "d5", "d6");
 139
 140        return 0;
 141}
 142
 143
 144static inline void *fb_memmove(void *d, const void *s, size_t count)
 145{
 146        if (d < s) {
 147                if (count < 16) {
 148                        asm volatile ("\n"
 149                                "       lsr.l   #1,%2 ; jcc 1f ; move.b (%1)+,(%0)+\n"
 150                                "1:     lsr.l   #1,%2 ; jcc 1f ; move.w (%1)+,(%0)+\n"
 151                                "1:     lsr.l   #1,%2 ; jcc 1f ; move.l (%1)+,(%0)+\n"
 152                                "1:     lsr.l   #1,%2 ; jcc 1f ; move.l (%1)+,(%0)+ ; move.l (%1)+,(%0)+\n"
 153                                "1:"
 154                                : "=a" (d), "=a" (s), "=d" (count)
 155                                : "0" (d), "1" (s), "2" (count));
 156                } else {
 157                        long tmp;
 158                        asm volatile ("\n"
 159                                "       move.l  %0,%3\n"
 160                                "       lsr.l   #1,%3 ; jcc 1f ; move.b (%1)+,(%0)+ ; subqw #1,%2\n"
 161                                "       lsr.l   #1,%3 ; jcs 2f\n"  /* %0 increased=>bit 2 switched*/
 162                                "       move.w  (%1)+,(%0)+  ; subqw  #2,%2 ; jra 2f\n"
 163                                "1:     lsr.l   #1,%3 ; jcc 2f\n"
 164                                "       move.w  (%1)+,(%0)+  ; subqw  #2,%2\n"
 165                                "2:     move.w  %2,%-; lsr.l #2,%2 ; jeq 6f\n"
 166                                "       lsr.l   #1,%2 ; jcc 3f ; move.l (%1)+,(%0)+\n"
 167                                "3:     lsr.l   #1,%2 ; jcc 4f ; move.l (%1)+,(%0)+ ; move.l (%1)+,(%0)+\n"
 168                                "4:     subq.l  #1,%2 ; jcs 6f\n"
 169                                "5:     move.l  (%1)+,(%0)+; move.l (%1)+,(%0)+\n"
 170                                "       move.l  (%1)+,(%0)+; move.l (%1)+,(%0)+\n"
 171                                "       dbra    %2,5b ; clr.w %2; subq.l #1,%2; jcc 5b\n"
 172                                "6:     move.w  %+,%2; btst #1,%2 ; jeq 7f ; move.w (%1)+,(%0)+\n"
 173                                "7:     btst    #0,%2 ; jeq 8f ; move.b (%1)+,(%0)+\n"
 174                                "8:"
 175                                : "=a" (d), "=a" (s), "=d" (count), "=d" (tmp)
 176                                : "0" (d), "1" (s), "2" (count));
 177                }
 178        } else {
 179                if (count < 16) {
 180                        asm volatile ("\n"
 181                                "       lsr.l   #1,%2 ; jcc 1f ; move.b -(%1),-(%0)\n"
 182                                "1:     lsr.l   #1,%2 ; jcc 1f ; move.w -(%1),-(%0)\n"
 183                                "1:     lsr.l   #1,%2 ; jcc 1f ; move.l -(%1),-(%0)\n"
 184                                "1:     lsr.l   #1,%2 ; jcc 1f ; move.l -(%1),-(%0) ; move.l -(%1),-(%0)\n"
 185                                "1:"
 186                                : "=a" (d), "=a" (s), "=d" (count)
 187                                : "0" ((char *) d + count), "1" ((char *) s + count), "2" (count));
 188                } else {
 189                        long tmp;
 190
 191                        asm volatile ("\n"
 192                                "       move.l  %0,%3\n"
 193                                "       lsr.l   #1,%3 ; jcc 1f ; move.b -(%1),-(%0) ; subqw #1,%2\n"
 194                                "       lsr.l   #1,%3 ; jcs 2f\n"  /* %0 increased=>bit 2 switched*/
 195                                "       move.w  -(%1),-(%0) ; subqw  #2,%2 ; jra 2f\n"
 196                                "1:     lsr.l   #1,%3 ; jcc 2f\n"
 197                                "       move.w  -(%1),-(%0) ; subqw  #2,%2\n"
 198                                "2:     move.w  %2,%-; lsr.l #2,%2 ; jeq 6f\n"
 199                                "       lsr.l   #1,%2 ; jcc 3f ; move.l -(%1),-(%0)\n"
 200                                "3:     lsr.l   #1,%2 ; jcc 4f ; move.l -(%1),-(%0) ; move.l -(%1),-(%0)\n"
 201                                "4:     subq.l  #1,%2 ; jcs 6f\n"
 202                                "5:     move.l  -(%1),-(%0); move.l -(%1),-(%0)\n"
 203                                "       move.l  -(%1),-(%0); move.l -(%1),-(%0)\n"
 204                                "       dbra    %2,5b ; clr.w %2; subq.l #1,%2; jcc 5b\n"
 205                                "6:     move.w  %+,%2; btst #1,%2 ; jeq 7f ; move.w -(%1),-(%0)\n"
 206                                "7:     btst    #0,%2 ; jeq 8f ; move.b -(%1),-(%0)\n"
 207                                "8:"
 208                                : "=a" (d), "=a" (s), "=d" (count), "=d" (tmp)
 209                                : "0" ((char *) d + count), "1" ((char *) s + count), "2" (count));
 210                }
 211        }
 212
 213        return 0;
 214}
 215
 216
 217/* ++andreas: Simple and fast version of memmove, assumes size is
 218   divisible by 16, suitable for moving the whole screen bitplane */
 219static inline void fast_memmove(char *dst, const char *src, size_t size)
 220{
 221        if (!size)
 222                return;
 223        if (dst < src)
 224                asm volatile ("\n"
 225                        "1:     movem.l (%0)+,%%d0/%%d1/%%a0/%%a1\n"
 226                        "       movem.l %%d0/%%d1/%%a0/%%a1,%1@\n"
 227                        "       addq.l  #8,%1; addq.l #8,%1\n"
 228                        "       dbra    %2,1b\n"
 229                        "       clr.w   %2; subq.l #1,%2\n"
 230                        "       jcc     1b"
 231                        : "=a" (src), "=a" (dst), "=d" (size)
 232                        : "0" (src), "1" (dst), "2" (size / 16 - 1)
 233                        : "d0", "d1", "a0", "a1", "memory");
 234        else
 235                asm volatile ("\n"
 236                        "1:     subq.l  #8,%0; subq.l #8,%0\n"
 237                        "       movem.l %0@,%%d0/%%d1/%%a0/%%a1\n"
 238                        "       movem.l %%d0/%%d1/%%a0/%%a1,-(%1)\n"
 239                        "       dbra    %2,1b\n"
 240                        "       clr.w   %2; subq.l #1,%2\n"
 241                        "       jcc 1b"
 242                        : "=a" (src), "=a" (dst), "=d" (size)
 243                        : "0" (src + size), "1" (dst + size), "2" (size / 16 - 1)
 244                        : "d0", "d1", "a0", "a1", "memory");
 245}
 246
 247#ifdef BPL
 248
 249/*
 250 * This expands a up to 8 bit color into two longs
 251 * for movel operations.
 252 */
 253static const u32 four2long[] = {
 254        0x00000000, 0x000000ff, 0x0000ff00, 0x0000ffff,
 255        0x00ff0000, 0x00ff00ff, 0x00ffff00, 0x00ffffff,
 256        0xff000000, 0xff0000ff, 0xff00ff00, 0xff00ffff,
 257        0xffff0000, 0xffff00ff, 0xffffff00, 0xffffffff,
 258};
 259
 260static inline void expand8_col2mask(u8 c, u32 m[])
 261{
 262        m[0] = four2long[c & 15];
 263#if BPL > 4
 264        m[1] = four2long[c >> 4];
 265#endif
 266}
 267
 268static inline void expand8_2col2mask(u8 fg, u8 bg, u32 fgm[], u32 bgm[])
 269{
 270        fgm[0] = four2long[fg & 15] ^ (bgm[0] = four2long[bg & 15]);
 271#if BPL > 4
 272        fgm[1] = four2long[fg >> 4] ^ (bgm[1] = four2long[bg >> 4]);
 273#endif
 274}
 275
 276/*
 277 * set an 8bit value to a color
 278 */
 279static inline void fill8_col(u8 *dst, u32 m[])
 280{
 281        u32 tmp = m[0];
 282        dst[0] = tmp;
 283        dst[2] = (tmp >>= 8);
 284#if BPL > 2
 285        dst[4] = (tmp >>= 8);
 286        dst[6] = tmp >> 8;
 287#endif
 288#if BPL > 4
 289        tmp = m[1];
 290        dst[8] = tmp;
 291        dst[10] = (tmp >>= 8);
 292        dst[12] = (tmp >>= 8);
 293        dst[14] = tmp >> 8;
 294#endif
 295}
 296
 297/*
 298 * set an 8bit value according to foreground/background color
 299 */
 300static inline void fill8_2col(u8 *dst, u8 fg, u8 bg, u32 mask)
 301{
 302        u32 fgm[2], bgm[2], tmp;
 303
 304        expand8_2col2mask(fg, bg, fgm, bgm);
 305
 306        mask |= mask << 8;
 307#if BPL > 2
 308        mask |= mask << 16;
 309#endif
 310        tmp = (mask & fgm[0]) ^ bgm[0];
 311        dst[0] = tmp;
 312        dst[2] = (tmp >>= 8);
 313#if BPL > 2
 314        dst[4] = (tmp >>= 8);
 315        dst[6] = tmp >> 8;
 316#endif
 317#if BPL > 4
 318        tmp = (mask & fgm[1]) ^ bgm[1];
 319        dst[8] = tmp;
 320        dst[10] = (tmp >>= 8);
 321        dst[12] = (tmp >>= 8);
 322        dst[14] = tmp >> 8;
 323#endif
 324}
 325
 326static const u32 two2word[] = {
 327        0x00000000, 0xffff0000, 0x0000ffff, 0xffffffff
 328};
 329
 330static inline void expand16_col2mask(u8 c, u32 m[])
 331{
 332        m[0] = two2word[c & 3];
 333#if BPL > 2
 334        m[1] = two2word[(c >> 2) & 3];
 335#endif
 336#if BPL > 4
 337        m[2] = two2word[(c >> 4) & 3];
 338        m[3] = two2word[c >> 6];
 339#endif
 340}
 341
 342static inline void expand16_2col2mask(u8 fg, u8 bg, u32 fgm[], u32 bgm[])
 343{
 344        bgm[0] = two2word[bg & 3];
 345        fgm[0] = two2word[fg & 3] ^ bgm[0];
 346#if BPL > 2
 347        bgm[1] = two2word[(bg >> 2) & 3];
 348        fgm[1] = two2word[(fg >> 2) & 3] ^ bgm[1];
 349#endif
 350#if BPL > 4
 351        bgm[2] = two2word[(bg >> 4) & 3];
 352        fgm[2] = two2word[(fg >> 4) & 3] ^ bgm[2];
 353        bgm[3] = two2word[bg >> 6];
 354        fgm[3] = two2word[fg >> 6] ^ bgm[3];
 355#endif
 356}
 357
 358static inline u32 *fill16_col(u32 *dst, int rows, u32 m[])
 359{
 360        while (rows) {
 361                *dst++ = m[0];
 362#if BPL > 2
 363                *dst++ = m[1];
 364#endif
 365#if BPL > 4
 366                *dst++ = m[2];
 367                *dst++ = m[3];
 368#endif
 369                rows--;
 370        }
 371        return dst;
 372}
 373
 374static inline void memmove32_col(void *dst, void *src, u32 mask, u32 h, u32 bytes)
 375{
 376        u32 *s, *d, v;
 377
 378        s = src;
 379        d = dst;
 380        do {
 381                v = (*s++ & mask) | (*d  & ~mask);
 382                *d++ = v;
 383#if BPL > 2
 384                v = (*s++ & mask) | (*d  & ~mask);
 385                *d++ = v;
 386#endif
 387#if BPL > 4
 388                v = (*s++ & mask) | (*d  & ~mask);
 389                *d++ = v;
 390                v = (*s++ & mask) | (*d  & ~mask);
 391                *d++ = v;
 392#endif
 393                d = (u32 *)((u8 *)d + bytes);
 394                s = (u32 *)((u8 *)s + bytes);
 395        } while (--h);
 396}
 397
 398#endif
 399
 400#endif /* _VIDEO_ATAFB_UTILS_H */
 401
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