src/glsl/nir/nir_opt_algebraic.py

   1 #! /usr/bin/env python
   2 #
   3 # Copyright (C) 2014 Intel Corporation
   4 #
   5 # Permission is hereby granted, free of charge, to any person obtaining a
   6 # copy of this software and associated documentation files (the "Software"),
   7 # to deal in the Software without restriction, including without limitation
   8 # the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9 # and/or sell copies of the Software, and to permit persons to whom the
  10 # Software is furnished to do so, subject to the following conditions:
  11 #
  12 # The above copyright notice and this permission notice (including the next
  13 # paragraph) shall be included in all copies or substantial portions of the
  14 # Software.
  15 #
  16 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19 # THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  22 # IN THE SOFTWARE.
  23 #
  24 # Authors:
  25 #    Jason Ekstrand (jason@jlekstrand.net)
  26
  27 import nir_algebraic
  28
  29 # Convenience variables
  30 a = 'a'
  31 b = 'b'
  32 c = 'c'
  33 d = 'd'
  34
  35 # Written in the form (<search>, <replace>) where <search> is an expression
  36 # and <replace> is either an expression or a value.  An expression is
  37 # defined as a tuple of the form (<op>, <src0>, <src1>, <src2>, <src3>)
  38 # where each source is either an expression or a value.  A value can be
  39 # either a numeric constant or a string representing a variable name.  For
  40 # constants, you have to be careful to make sure that it is the right type
  41 # because python is unaware of the source and destination types of the
  42 # opcodes.
  43
  44 optimizations = [
  45    (('fneg', ('fneg', a)), a),
  46    (('ineg', ('ineg', a)), a),
  47    (('fabs', ('fabs', a)), ('fabs', a)),
  48    (('fabs', ('fneg', a)), ('fabs', a)),
  49    (('iabs', ('iabs', a)), ('iabs', a)),
  50    (('iabs', ('ineg', a)), ('iabs', a)),
  51    (('fadd', a, 0.0), a),
  52    (('iadd', a, 0), a),
  53    (('fmul', a, 0.0), 0.0),
  54    (('imul', a, 0), 0),
  55    (('fmul', a, 1.0), a),
  56    (('imul', a, 1), a),
  57    (('fmul', a, -1.0), ('fneg', a)),
  58    (('imul', a, -1), ('ineg', a)),
  59    (('ffma', 0.0, a, b), b),
  60    (('ffma', a, 0.0, b), b),
  61    (('ffma', a, b, 0.0), ('fmul', a, b)),
  62    (('ffma', a, 1.0, b), ('fadd', a, b)),
  63    (('ffma', 1.0, a, b), ('fadd', a, b)),
  64    (('flrp', a, b, 0.0), a),
  65    (('flrp', a, b, 1.0), b),
  66    (('flrp', a, a, b), a),
  67    (('flrp', 0.0, a, b), ('fmul', a, b)),
  68    (('fadd', ('fmul', a, b), c), ('ffma', a, b, c)),
  69    # Comparison simplifications
  70    (('inot', ('flt', a, b)), ('fge', a, b)),
  71    (('inot', ('fge', a, b)), ('flt', a, b)),
  72    (('inot', ('ilt', a, b)), ('ige', a, b)),
  73    (('inot', ('ige', a, b)), ('ilt', a, b)),
  74    (('ine', ('flt', a, b), 0), ('flt', a, b)),
  75    (('ine', ('fge', a, b), 0), ('fge', a, b)),
  76    (('ine', ('ilt', a, b), 0), ('ilt', a, b)),
  77    (('ine', ('ige', a, b), 0), ('ige', a, b)),
  78    (('flt', ('fadd', a, b), 0.0), ('flt', a, ('fneg', b))),
  79    (('fge', ('fadd', a, b), 0.0), ('fge', a, ('fneg', b))),
  80    (('feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
  81    (('fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
  82    (('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
  83    (('fmin', ('fmax', a, 1.0), 0.0), ('fsat', a)),
  84    # Logical and bit operations
  85    (('fand', a, 0.0), 0.0),
  86    (('iand', a, a), a),
  87    (('iand', a, 0), 0),
  88    (('ior', a, a), a),
  89    (('ior', a, 0), a),
  90    (('fxor', a, a), 0.0),
  91    (('ixor', a, a), 0),
  92    (('inot', ('inot', a)), a),
  93    # DeMorgan's Laws
  94    (('iand', ('inot', a), ('inot', b)), ('inot', ('ior',  a, b))),
  95    (('ior',  ('inot', a), ('inot', b)), ('inot', ('iand', a, b))),
  96    # Shift optimizations
  97    (('ishl', 0, a), 0),
  98    (('ishl', a, 0), a),
  99    (('ishr', 0, a), 0),
 100    (('ishr', a, 0), a),
 101    (('ushr', 0, a), 0),
 102    (('ushr', a, 0), 0),
 103    # Exponential/logarithmic identities
 104    (('fexp2', ('flog2', a)), a), # 2^lg2(a) = a
 105    (('fexp',  ('flog',  a)), a), # e^ln(a)  = a
 106    (('flog2', ('fexp2', a)), a), # lg2(2^a) = a
 107    (('flog',  ('fexp',  a)), a), # ln(e^a)  = a
 108    (('fexp2', ('fmul', ('flog2', a), b)), ('fpow', a, b)), # 2^(lg2(a)*b) = a^b
 109    (('fexp',  ('fmul', ('flog', a), b)),  ('fpow', a, b)), # e^(ln(a)*b) = a^b
 110    (('fpow', a, 1.0), a),
 111    (('fpow', a, 2.0), ('fmul', a, a)),
 112    (('fpow', 2.0, a), ('fexp2', a)),
 113    # Division and reciprocal
 114    (('fdiv', 1.0, a), ('frcp', a)),
 115    (('frcp', ('frcp', a)), a),
 116    (('frcp', ('fsqrt', a)), ('frsq', a)),
 117    (('frcp', ('frsq', a)), ('fsqrt', a)),
 118
 119 # This one may not be exact
 120    (('feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
 121 ]
 122
 123 print nir_algebraic.AlgebraicPass("nir_opt_algebraic", optimizations).render()