release/src-rt-6.x.4708/linux/linux-2.6.36/arch/xtensa/include/asm/asmmacro.h

   1 /*
   2  * include/asm-xtensa/asmmacro.h
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 2005 Tensilica Inc.
   9  */
  10
  11 #ifndef _XTENSA_ASMMACRO_H
  12 #define _XTENSA_ASMMACRO_H
  13
  14 #include <variant/core.h>
  15
  16 /*
  17  * Some little helpers for loops. Use zero-overhead-loops
  18  * where applicable and if supported by the processor.
  19  *
  20  * __loopi ar, at, size, inc
  21  *         ar   register initialized with the start address
  22  *         at   scratch register used by macro
  23  *         size size immediate value
  24  *         inc  increment
  25  *
  26  * __loops ar, as, at, inc_log2[, mask_log2][, cond][, ncond]
  27  *         ar   register initialized with the start address
  28  *         as   register initialized with the size
  29  *         at   scratch register use by macro
  30  *         inc_log2     increment [in log2]
  31  *         mask_log2    mask [in log2]
  32  *         cond         true condition (used in loop'cond')
  33  *         ncond        false condition (used in b'ncond')
  34  *
  35  * __loop  as
  36  *         restart loop. 'as' register must not have been modified!
  37  *
  38  * __endla ar, at, incr
  39  *         ar   start address (modified)
  40  *         as   scratch register used by macro
  41  *         inc  increment
  42  */
  43
  44 /*
  45  * loop for given size as immediate
  46  */
  47
  48         .macro  __loopi ar, at, size, incr
  49
  50 #if XCHAL_HAVE_LOOPS
  51                 movi    \at, ((\size + \incr - 1) / (\incr))
  52                 loop    \at, 99f
  53 #else
  54                 addi    \at, \ar, \size
  55                 98:
  56 #endif
  57
  58         .endm
  59
  60 /*
  61  * loop for given size in register
  62  */
  63
  64         .macro  __loops ar, as, at, incr_log2, mask_log2, cond, ncond
  65
  66 #if XCHAL_HAVE_LOOPS
  67                 .ifgt \incr_log2 - 1
  68                         addi    \at, \as, (1 << \incr_log2) - 1
  69                         .ifnc \mask_log2,
  70                                 extui   \at, \at, \incr_log2, \mask_log2
  71                         .else
  72                                 srli    \at, \at, \incr_log2
  73                         .endif
  74                 .endif
  75                 loop\cond       \at, 99f
  76 #else
  77                 .ifnc \mask_log2,
  78                         extui   \at, \as, \incr_log2, \mask_log2
  79                 .else
  80                         .ifnc \ncond,
  81                                 srli    \at, \as, \incr_log2
  82                         .endif
  83                 .endif
  84                 .ifnc \ncond,
  85                         b\ncond \at, 99f
  86
  87                 .endif
  88                 .ifnc \mask_log2,
  89                         slli    \at, \at, \incr_log2
  90                         add     \at, \ar, \at
  91                 .else
  92                         add     \at, \ar, \as
  93                 .endif
  94 #endif
  95                 98:
  96
  97         .endm
  98
  99 /*
 100  * loop from ar to ax
 101  */
 102
 103         .macro  __loopt ar, as, at, incr_log2
 104
 105 #if XCHAL_HAVE_LOOPS
 106                 sub     \at, \as, \ar
 107                 .ifgt   \incr_log2 - 1
 108                         addi    \at, \at, (1 << \incr_log2) - 1
 109                         srli    \at, \at, \incr_log2
 110                 .endif
 111                 loop    \at, 99f
 112 #else
 113                 98:
 114 #endif
 115
 116         .endm
 117
 118 /*
 119  * restart loop. registers must be unchanged
 120  */
 121
 122         .macro  __loop  as
 123
 124 #if XCHAL_HAVE_LOOPS
 125                 loop    \as, 99f
 126 #else
 127                 98:
 128 #endif
 129
 130         .endm
 131
 132 /*
 133  * end of loop with no increment of the address.
 134  */
 135
 136         .macro  __endl  ar, as
 137 #if !XCHAL_HAVE_LOOPS
 138                 bltu    \ar, \as, 98b
 139 #endif
 140                 99:
 141         .endm
 142
 143 /*
 144  * end of loop with increment of the address.
 145  */
 146
 147         .macro  __endla ar, as, incr
 148                 addi    \ar, \ar, \incr
 149                 __endl  \ar \as
 150         .endm
 151
 152
 153 #endif /* _XTENSA_ASMMACRO_H */