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, as, incr
  39  *         ar   start address (modified)
  40  *         as   scratch register used by __loops/__loopi macros or
  41  *              end address used by __loopt macro
  42  *         inc  increment
  43  */
  44
  45 /*
  46  * loop for given size as immediate
  47  */
  48
  49         .macro  __loopi ar, at, size, incr
  50
  51 #if XCHAL_HAVE_LOOPS
  52                 movi    \at, ((\size + \incr - 1) / (\incr))
  53                 loop    \at, 99f
  54 #else
  55                 addi    \at, \ar, \size
  56                 98:
  57 #endif
  58
  59         .endm
  60
  61 /*
  62  * loop for given size in register
  63  */
  64
  65         .macro  __loops ar, as, at, incr_log2, mask_log2, cond, ncond
  66
  67 #if XCHAL_HAVE_LOOPS
  68                 .ifgt \incr_log2 - 1
  69                         addi    \at, \as, (1 << \incr_log2) - 1
  70                         .ifnc \mask_log2,
  71                                 extui   \at, \at, \incr_log2, \mask_log2
  72                         .else
  73                                 srli    \at, \at, \incr_log2
  74                         .endif
  75                 .endif
  76                 loop\cond       \at, 99f
  77 #else
  78                 .ifnc \mask_log2,
  79                         extui   \at, \as, \incr_log2, \mask_log2
  80                 .else
  81                         .ifnc \ncond,
  82                                 srli    \at, \as, \incr_log2
  83                         .endif
  84                 .endif
  85                 .ifnc \ncond,
  86                         b\ncond \at, 99f
  87
  88                 .endif
  89                 .ifnc \mask_log2,
  90                         slli    \at, \at, \incr_log2
  91                         add     \at, \ar, \at
  92                 .else
  93                         add     \at, \ar, \as
  94                 .endif
  95 #endif
  96                 98:
  97
  98         .endm
  99
 100 /*
 101  * loop from ar to as
 102  */
 103
 104         .macro  __loopt ar, as, at, incr_log2
 105
 106 #if XCHAL_HAVE_LOOPS
 107                 sub     \at, \as, \ar
 108                 .ifgt   \incr_log2 - 1
 109                         addi    \at, \at, (1 << \incr_log2) - 1
 110                         srli    \at, \at, \incr_log2
 111                 .endif
 112                 loop    \at, 99f
 113 #else
 114                 98:
 115 #endif
 116
 117         .endm
 118
 119 /*
 120  * restart loop. registers must be unchanged
 121  */
 122
 123         .macro  __loop  as
 124
 125 #if XCHAL_HAVE_LOOPS
 126                 loop    \as, 99f
 127 #else
 128                 98:
 129 #endif
 130
 131         .endm
 132
 133 /*
 134  * end of loop with no increment of the address.
 135  */
 136
 137         .macro  __endl  ar, as
 138 #if !XCHAL_HAVE_LOOPS
 139                 bltu    \ar, \as, 98b
 140 #endif
 141                 99:
 142         .endm
 143
 144 /*
 145  * end of loop with increment of the address.
 146  */
 147
 148         .macro  __endla ar, as, incr
 149                 addi    \ar, \ar, \incr
 150                 __endl  \ar \as
 151         .endm
 152
 153
 154 #endif /* _XTENSA_ASMMACRO_H */