nir: Separate a weird compare with zero to two compares with zero

min(a+b, c+d) >= 0 becomes (a+b >= 0 && c+d >= 0).

No shader-db changes, but it does prevent 6 to 12 instruction
regressions in the next patch on all measured Intel platforms.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Reviewed-by: Elie Tournier <elie.tournier@collabora.com>

diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index c097f128323c20c5839353cac60bdcdc0e09028f..bee135c235c92785195db6470de97ebf68650c25 100644 (file)
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -596,6 +596,8 @@ late_optimizations = [
    (('~feq', ('fadd', a, b), 0.0), ('feq', a, ('fneg', b))),
    (('~fne', ('fadd', a, b), 0.0), ('fne', a, ('fneg', b))),
 
+   (('~fge', ('fmin(is_used_once)', ('fadd(is_used_once)', a, b), ('fadd', c, d)), 0.0), ('iand', ('fge', a, ('fneg', b)), ('fge', c, ('fneg', d)))),
+
    (('fdot2', a, b), ('fdot_replicated2', a, b), 'options->fdot_replicates'),
    (('fdot3', a, b), ('fdot_replicated3', a, b), 'options->fdot_replicates'),
    (('fdot4', a, b), ('fdot_replicated4', a, b), 'options->fdot_replicates'),