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 = [
  34    (('pack_unorm_4x8', a), ('pack_32_4x8', ('f2u8', ('fround_even', ('fmul', ('fsat', a), 255.0))))),
  35
  36    # Allows us to schedule as a multiply by 2
  37    (('~fadd', ('fadd', a, b), a), ('fadd', ('fadd', a, a), b)),
  38 ]
  39
  40 algebraic_late = [
  41     # ineg must be lowered late, but only for integers; floats will try to
  42     # have modifiers attached... hence why this has to be here rather than
  43     # a more standard lower_negate approach
  44
  45     (('ineg', a), ('isub', 0, a)),
  46
  47     # Likewise we want fsub lowered but not isub
  48     (('fsub', a, b), ('fadd', a, ('fneg', b))),
  49
  50     # These two special-cases save space/an op than the actual csel op +
  51     # scheduler flexibility
  52
  53     (('b32csel', a, 'b@32', 0), ('iand', a, b)),
  54     (('b32csel', a, 0, 'b@32'), ('iand', ('inot', a), b)),
  55
  56     # Fuse sat_signed. This should probably be shared with Bifrost
  57     (('~fmin', ('fmax', a, -1.0), 1.0), ('fsat_signed', a)),
  58     (('~fmax', ('fmin', a, 1.0), -1.0), ('fsat_signed', a)),
  59
  60     # Fuse clamp_positive. This should probably be shared with Utgard/bifrost
  61     (('fmax', a, 0.0), ('fclamp_pos', a)),
  62
  63     (('ishl', 'a@16', b), ('u2u16', ('ishl', ('u2u32', a), b))),
  64     (('ishr', 'a@16', b), ('i2i16', ('ishr', ('i2i32', a), b))),
  65     (('ushr', 'a@16', b), ('u2u16', ('ushr', ('u2u32', a), b))),
  66
  67     (('ishl', 'a@8', b), ('u2u8', ('u2u16', ('ishl', ('u2u32', ('u2u16', a)), b)))),
  68     (('ishr', 'a@8', b), ('i2i8', ('i2i16', ('ishr', ('i2i32', ('i2i16', a)), b)))),
  69     (('ushr', 'a@8', b), ('u2u8', ('u2u16', ('ushr', ('u2u32', ('u2u16', a)), b)))),
  70
  71     # Canonical form. The scheduler will convert back if it makes sense.
  72     (('fmul', a, 2.0), ('fadd', a, a))
  73 ]
  74
  75
  76 # Midgard is able to type convert down by only one "step" per instruction; if
  77 # NIR wants more than one step, we need to break up into multiple instructions.
  78 # Nevertheless, we can do both a size step and a floating/int step at once.
  79
  80 converts = []
  81
  82 for op in ('u2u', 'i2i', 'f2f', 'i2f', 'u2f', 'f2i', 'f2u'):
  83     srcsz_max = 64
  84     dstsz_max = 64
  85     # 8 bit float doesn't exist
  86     srcsz_min = 8 if op[0] != 'f' else 16
  87     dstsz_min = 8 if op[2] != 'f' else 16
  88     dstsz = dstsz_min
  89     # Iterate over all possible destination and source sizes
  90     while dstsz <= dstsz_max:
  91         srcsz = srcsz_min
  92         while srcsz <= srcsz_max:
  93             # Size converter lowering is only needed if src and dst sizes are
  94             # spaced by a factor > 2.
  95             if srcsz != dstsz and (srcsz * 2 != dstsz and srcsz != dstsz * 2):
  96                 cursz = srcsz
  97                 rule = a
  98                 # When converting down we first do the type conversion followed
  99                 # by one or more size conversions. When converting up, we do
 100                 # the type conversion at the end. This way we don't have to
 101                 # deal with the fact that f2f8 doesn't exists.
 102                 sizeconvop = op[0] + '2' + op[0] if srcsz < dstsz else op[2] + '2' + op[2]
 103                 if srcsz > dstsz and op[0] != op[2]:
 104                     rule = (op + str(int(cursz)), rule)
 105                 while cursz != dstsz:
 106                     cursz = cursz / 2 if dstsz < srcsz else cursz * 2
 107                     rule = (sizeconvop + str(int(cursz)), rule)
 108                 if srcsz < dstsz and op[0] != op[2]:
 109                     rule = (op + str(int(cursz)), rule)
 110                 converts += [((op + str(int(dstsz)), 'a@' + str(int(srcsz))), rule)]
 111             srcsz *= 2
 112         dstsz *= 2
 113
 114 # Try to force constants to the right
 115 constant_switch = [
 116         # fge gets flipped to fle, so we invert to keep the order
 117         (('fge', 'a', '#b'), (('inot', ('flt', a, b)))),
 118         (('fge32', 'a', '#b'), (('inot', ('flt32', a, b)))),
 119         (('ige32', 'a', '#b'), (('inot', ('ilt32', a, b)))),
 120         (('uge32', 'a', '#b'), (('inot', ('ult32', a, b)))),
 121
 122         # fge gets mapped to fle with a flip
 123         (('flt32', '#a', 'b'), ('inot', ('fge32', a, b))),
 124         (('ilt32', '#a', 'b'), ('inot', ('ige32', a, b))),
 125         (('ult32', '#a', 'b'), ('inot', ('uge32', a, b)))
 126 ]
 127
 128 # ..since the above switching happens after algebraic stuff is done
 129 cancel_inot = [
 130         (('inot', ('inot', a)), a)
 131 ]
 132
 133 # Midgard scales fsin/fcos arguments by pi.
 134 # Pass must be run only once, after the main loop
 135
 136 scale_trig = [
 137         (('fsin', a), ('fsin', ('fdiv', a, math.pi))),
 138         (('fcos', a), ('fcos', ('fdiv', a, math.pi))),
 139 ]
 140
 141 def main():
 142     parser = argparse.ArgumentParser()
 143     parser.add_argument('-p', '--import-path', required=True)
 144     args = parser.parse_args()
 145     sys.path.insert(0, args.import_path)
 146     run()
 147
 148
 149 def run():
 150     import nir_algebraic  # pylint: disable=import-error
 151
 152     print('#include "midgard_nir.h"')
 153
 154     print(nir_algebraic.AlgebraicPass("midgard_nir_lower_algebraic_early",
 155                                       algebraic).render())
 156
 157     print(nir_algebraic.AlgebraicPass("midgard_nir_lower_algebraic_late",
 158                                       algebraic_late + converts + constant_switch).render())
 159
 160     print(nir_algebraic.AlgebraicPass("midgard_nir_scale_trig",
 161                                       scale_trig).render())
 162
 163     print(nir_algebraic.AlgebraicPass("midgard_nir_cancel_inot",
 164                                       cancel_inot).render())
 165
 166
 167 if __name__ == '__main__':
 168     main()