937   register FSERRPTR errorptr;   /* => fserrors[] at column before current */  in pass2_fs_dither()  local
962       errorptr = cquantize->fserrors + (width + 1) * 3; /* => entry after last column */  in pass2_fs_dither()
968       errorptr = cquantize->fserrors; /* => entry before first real column */  in pass2_fs_dither()
986       cur0 = RIGHT_SHIFT(cur0 + errorptr[dir3 + 0] + 8, 4);  in pass2_fs_dither()
987       cur1 = RIGHT_SHIFT(cur1 + errorptr[dir3 + 1] + 8, 4);  in pass2_fs_dither()
988       cur2 = RIGHT_SHIFT(cur2 + errorptr[dir3 + 2] + 8, 4);  in pass2_fs_dither()
1030         errorptr[0] = (FSERROR)(bpreverr0 + cur0 * 3);  in pass2_fs_dither()
1035         errorptr[1] = (FSERROR)(bpreverr1 + cur1 * 3);  in pass2_fs_dither()
1040         errorptr[2] = (FSERROR)(bpreverr2 + cur2 * 3);  in pass2_fs_dither()
1051       errorptr += dir3;         /* advance errorptr to current column */  in pass2_fs_dither()
1057     errorptr[0] = (FSERROR)bpreverr0; /* unload prev errs into array */  in pass2_fs_dither()
1058     errorptr[1] = (FSERROR)bpreverr1;  in pass2_fs_dither()
1059     errorptr[2] = (FSERROR)bpreverr2;  in pass2_fs_dither()