This could be squashed with the previous commit. I kept it separate to
ease review.
v2: Add some missing cases. Use nir_src_is_const helper. Both
suggested by Caio. Use a table for mapping source ranges to a result
range.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
This could be squashed with the previous commit. I kept it separate to
ease review.
v2: Use a switch statement and add more comments. Both suggested by
Caio.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Most integer operations are omitted because dealing with integer
overflow is hard. There are a few things that could be smarter if there
was a small amount more tracking of ranges of integer types (i.e.,
operands are Boolean, operand values fit in 16 bits, etc.).
The changes to nir_search_helpers.h are included in this patch to
simplify reordering the changes to nir_opt_algebraic.py.
v2: Memoize range analysis results. Without this, some shaders appear
to get stuck in infinite loops.
v3: Rebase on many months of Mesa changes, including 1-bit Boolean
changes.
v4: Rebase on "nir: Drop imov/fmov in favor of one mov instruction".
v5: Use nir_alu_srcs_equal for detecting (a*a). Previously just the SSA
value was compared, and this incorrectly matched (a.x*a.y).
v6: Many code improvements including (but not limited to) better names,
more comments, and better use of helper functions. All suggested by
Caio. Rework the handling of several opcodes to use a table for mapping
source ranges to a result range. This change fixed a bug that caused
fmax(gt_zero, ge_zero) to be incorrectly recognized as ge_zero.
Slightly tighten the range of fmul by recognizing that x*x is gt_zero if
x is gt_zero. Add similar handling for -x*x.
v7: Use _______ in the tables as an alias for unknown. Suggested by
Caio.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
