diff options
Diffstat (limited to 'src/compiler/nir/nir_opt_algebraic.py')
| -rw-r--r-- | src/compiler/nir/nir_opt_algebraic.py | 45 |
1 files changed, 30 insertions, 15 deletions
diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py index ddfe94d9e73..dd41931b345 100644 --- a/src/compiler/nir/nir_opt_algebraic.py +++ b/src/compiler/nir/nir_opt_algebraic.py @@ -138,7 +138,10 @@ optimizations = [ (('~fmax', ('fmin', a, 1.0), 0.0), ('fsat', a), '!options->lower_fsat'), (('fsat', a), ('fmin', ('fmax', a, 0.0), 1.0), 'options->lower_fsat'), (('fsat', ('fsat', a)), ('fsat', a)), - (('fmin', ('fmax', ('fmin', ('fmax', a, 0.0), 1.0), 0.0), 1.0), ('fmin', ('fmax', a, 0.0), 1.0)), + (('fmin', ('fmax', ('fmin', ('fmax', a, b), c), b), c), ('fmin', ('fmax', a, b), c)), + (('imin', ('imax', ('imin', ('imax', a, b), c), b), c), ('imin', ('imax', a, b), c)), + (('umin', ('umax', ('umin', ('umax', a, b), c), b), c), ('umin', ('umax', a, b), c)), + (('extract_u8', ('imin', ('imax', a, 0), 0xff), 0), ('imin', ('imax', a, 0), 0xff)), (('~ior', ('flt', a, b), ('flt', a, c)), ('flt', a, ('fmax', b, c))), (('~ior', ('flt', a, c), ('flt', b, c)), ('flt', ('fmin', a, b), c)), (('~ior', ('fge', a, b), ('fge', a, c)), ('fge', a, ('fmin', b, c))), @@ -275,6 +278,14 @@ optimizations = [ (('fmul', ('fneg', a), b), ('fneg', ('fmul', a, b))), (('imul', ('ineg', a), b), ('ineg', ('imul', a, b))), + # Reassociate constants in add/mul chains so they can be folded together. + # For now, we only handle cases where the constants are separated by + # a single non-constant. We could do better eventually. + (('~fmul', '#a', ('fmul', b, '#c')), ('fmul', ('fmul', a, c), b)), + (('imul', '#a', ('imul', b, '#c')), ('imul', ('imul', a, c), b)), + (('~fadd', '#a', ('fadd', b, '#c')), ('fadd', ('fadd', a, c), b)), + (('iadd', '#a', ('iadd', b, '#c')), ('iadd', ('iadd', a, c), b)), + # Misc. lowering (('fmod', a, b), ('fsub', a, ('fmul', b, ('ffloor', ('fdiv', a, b)))), 'options->lower_fmod'), (('frem', a, b), ('fsub', a, ('fmul', b, ('ftrunc', ('fdiv', a, b)))), 'options->lower_fmod'), @@ -362,26 +373,30 @@ optimizations = [ ] def fexp2i(exp): - # We assume that exp is already in range. + # We assume that exp is already in the range [-126, 127]. return ('ishl', ('iadd', exp, 127), 23) def ldexp32(f, exp): - # First, we clamp exp to a reasonable range. The maximum range that we - # need is the largest range for an exponent, ([-127, 128] if you include - # inf and 0) plus the number of mantissa bits in either direction to - # account for denormals. This means that we need at least a range of - # [-150, 151]. For our implementation, however, what we really care - # about is that neither exp/2 nor exp-exp/2 go out of the regular range - # for floating-point exponents. + # First, we clamp exp to a reasonable range. The maximum possible range + # for a normal exponent is [-126, 127] and, throwing in denormals, you get + # a maximum range of [-149, 127]. This means that we can potentially have + # a swing of +-276. If you start with FLT_MAX, you actually have to do + # ldexp(FLT_MAX, -278) to get it to flush all the way to zero. The GLSL + # spec, on the other hand, only requires that we handle an exponent value + # in the range [-126, 128]. This implementation is *mostly* correct; it + # handles a range on exp of [-252, 254] which allows you to create any + # value (including denorms if the hardware supports it) and to adjust the + # exponent of any normal value to anything you want. exp = ('imin', ('imax', exp, -252), 254) # Now we compute two powers of 2, one for exp/2 and one for exp-exp/2. - # While the spec technically defines ldexp as f * 2.0^exp, simply - # multiplying once doesn't work when denormals are involved because - # 2.0^exp may not be representable even though ldexp(f, exp) is (see - # comments above about range). Instead, we create two powers of two and - # multiply by them each in turn. That way the effective range of our - # exponent is doubled. + # (We use ishr which isn't the same for -1, but the -1 case still works + # since we use exp-exp/2 as the second exponent.) While the spec + # technically defines ldexp as f * 2.0^exp, simply multiplying once doesn't + # work with denormals and doesn't allow for the full swing in exponents + # that you can get with normalized values. Instead, we create two powers + # of two and multiply by them each in turn. That way the effective range + # of our exponent is doubled. pow2_1 = fexp2i(('ishr', exp, 1)) pow2_2 = fexp2i(('isub', exp, ('ishr', exp, 1))) return ('fmul', ('fmul', f, pow2_1), pow2_2) |