src/panfrost/midgard/midgard_nir_algebraic.py

   1 #
   2 # Copyright (C) 2018 Alyssa Rosenzweig
   3 #
   4 # Copyright (C) 2016 Intel Corporation
   5 #
   6 # Permission is hereby granted, free of charge, to any person obtaining a
   7 # copy of this software and associated documentation files (the "Software"),
   8 # to deal in the Software without restriction, including without limitation
   9 # the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10 # and/or sell copies of the Software, and to permit persons to whom the
  11 # Software is furnished to do so, subject to the following conditions:
  12 #
  13 # The above copyright notice and this permission notice (including the next
  14 # paragraph) shall be included in all copies or substantial portions of the
  15 # Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20 # THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  23 # IN THE SOFTWARE.
  24
  25 import argparse
  26 import sys
  27 import math
  28
  29 a = 'a'
  30 b = 'b'
  31 c = 'c'
  32
  33 algebraic_late = [
  34     # ineg must be lowered late, but only for integers; floats will try to
  35     # have modifiers attached... hence why this has to be here rather than
  36     # a more standard lower_negate approach
  37
  38     (('ineg', a), ('isub', 0, a)),
  39
  40     # Likewise we want fsub lowered but not isub
  41     (('fsub', a, b), ('fadd', a, ('fneg', b))),
  42
  43     # These two special-cases save space/an op than the actual csel op +
  44     # scheduler flexibility
  45
  46     (('b32csel', a, 'b@32', 0), ('iand', a, b)),
  47     (('b32csel', a, 0, 'b@32'), ('iand', ('inot', a), b)),
  48
  49     # Fuse sat_signed. This should probably be shared with Bifrost
  50     (('~fmin', ('fmax', a, -1.0), 1.0), ('fsat_signed', a)),
  51     (('~fmax', ('fmin', a, 1.0), -1.0), ('fsat_signed', a)),
  52
  53     # Fuse clamp_positive. This should probably be shared with Utgard/bifrost
  54     (('fmax', a, 0.0), ('fclamp_pos', a)),
  55 ]
  56
  57
  58 # Midgard is able to type convert down by only one "step" per instruction; if
  59 # NIR wants more than one step, we need to break up into multiple instructions
  60
  61 converts = []
  62
  63 for op in ('u2u', 'i2i', 'f2f', 'i2f', 'u2f', 'f2i', 'f2u'):
  64     srcsz_max = 64
  65     dstsz_max = 64
  66     # 8 bit float doesn't exist
  67     srcsz_min = 8 if op[0] != 'f' else 16
  68     dstsz_min = 8 if op[2] != 'f' else 16
  69     dstsz = dstsz_min
  70     # Iterate over all possible destination and source sizes
  71     while dstsz <= dstsz_max:
  72         srcsz = srcsz_min
  73         while srcsz <= srcsz_max:
  74             # Size converter lowering is only needed if src and dst sizes are
  75             # spaced by a factor > 2.
  76             # Type converter lowering is needed as soon as src_size != dst_size
  77             if srcsz != dstsz and ((srcsz * 2 != dstsz and srcsz != dstsz * 2) or op[0] != op[2]):
  78                 cursz = srcsz
  79                 rule = a
  80                 # When converting down we first do the type conversion followed
  81                 # by one or more size conversions. When converting up, we do
  82                 # the type conversion at the end. This way we don't have to
  83                 # deal with the fact that f2f8 doesn't exists.
  84                 sizeconvop = op[0] + '2' + op[0] if srcsz < dstsz else op[2] + '2' + op[2]
  85                 if srcsz > dstsz and op[0] != op[2]:
  86                     rule = (op + str(int(cursz)), rule)
  87                 while cursz != dstsz:
  88                     cursz = cursz / 2 if dstsz < srcsz else cursz * 2
  89                     rule = (sizeconvop + str(int(cursz)), rule)
  90                 if srcsz < dstsz and op[0] != op[2]:
  91                     rule = (op + str(int(cursz)), rule)
  92                 converts += [((op + str(int(dstsz)), 'a@' + str(int(srcsz))), rule)]
  93             srcsz *= 2
  94         dstsz *= 2
  95
  96 # Midgard outputs fp32 for specials. The f2f32 will be folded in later.
  97 SPECIAL = ['fexp2', 'flog2', 'fsin', 'fcos', 'frcp', 'frsq']
  98
  99 for op in SPECIAL:
 100         converts += [((op + '@16', a), ('f2f16', (op, ('f2f32', a))))]
 101
 102 # Try to force constants to the right
 103 constant_switch = [
 104         # fge gets flipped to fle, so we invert to keep the order
 105         (('fge', 'a', '#b'), (('inot', ('flt', a, b)))),
 106         (('fge32', 'a', '#b'), (('inot', ('flt32', a, b)))),
 107         (('ige32', 'a', '#b'), (('inot', ('ilt32', a, b)))),
 108         (('uge32', 'a', '#b'), (('inot', ('ult32', a, b)))),
 109
 110         # fge gets mapped to fle with a flip
 111         (('flt32', '#a', 'b'), ('inot', ('fge32', a, b))),
 112         (('ilt32', '#a', 'b'), ('inot', ('ige32', a, b))),
 113         (('ult32', '#a', 'b'), ('inot', ('uge32', a, b)))
 114 ]
 115
 116 # ..since the above switching happens after algebraic stuff is done
 117 cancel_inot = [
 118         (('inot', ('inot', a)), a)
 119 ]
 120
 121 # Midgard scales fsin/fcos arguments by pi.
 122 # Pass must be run only once, after the main loop
 123
 124 scale_trig = [
 125         (('fsin', a), ('fsin', ('fdiv', a, math.pi))),
 126         (('fcos', a), ('fcos', ('fdiv', a, math.pi))),
 127 ]
 128
 129 def main():
 130     parser = argparse.ArgumentParser()
 131     parser.add_argument('-p', '--import-path', required=True)
 132     args = parser.parse_args()
 133     sys.path.insert(0, args.import_path)
 134     run()
 135
 136
 137 def run():
 138     import nir_algebraic  # pylint: disable=import-error
 139
 140     print('#include "midgard_nir.h"')
 141
 142     print(nir_algebraic.AlgebraicPass("midgard_nir_lower_algebraic_late",
 143                                       algebraic_late + converts + constant_switch).render())
 144
 145     print(nir_algebraic.AlgebraicPass("midgard_nir_scale_trig",
 146                                       scale_trig).render())
 147
 148     print(nir_algebraic.AlgebraicPass("midgard_nir_cancel_inot",
 149                                       cancel_inot).render())
 150
 151
 152 if __name__ == '__main__':
 153     main()