nir/algebraic: eliminate exact a*0.0 if float execution mode allow it

fossil-db (GFX10):
Totals from 611 (0.44% of 139391) affected shaders:
SGPRs: 40528 -> 40288 (-0.59%)
VGPRs: 16136 -> 16152 (+0.10%); split: -0.15%, +0.25%
CodeSize: 970192 -> 951036 (-1.97%)
MaxWaves: 10561 -> 10557 (-0.04%); split: +0.08%, -0.11%
Instrs: 174874 -> 172879 (-1.14%); split: -1.18%, +0.04%

fossil-db (GFX10.3):
Totals from 611 (0.44% of 139391) affected shaders:
SGPRs: 40680 -> 40488 (-0.47%)
VGPRs: 18368 -> 18276 (-0.50%); split: -0.57%, +0.07%
CodeSize: 1050712 -> 1033624 (-1.63%); split: -1.64%, +0.02%
MaxWaves: 8658 -> 8674 (+0.18%)
Instrs: 205364 -> 201220 (-2.02%)

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5523>
This commit is contained in:
Rhys Perry
2020-07-15 11:19:56 +01:00
parent 614ab26afd
commit b729cd58d7

View File

@@ -147,6 +147,9 @@ optimizations = [
(('~fadd', a, ('fadd', ('fneg', a), b)), b),
(('fadd', ('fsat', a), ('fsat', ('fneg', a))), ('fsat', ('fabs', a))),
(('~fmul', a, 0.0), 0.0),
# The only effect a*0.0 should have is when 'a' is infinity, -0.0 or NaN
(('fmul', 'a@16', 0.0), 0.0, '!'+signed_zero_inf_nan_preserve_16),
(('fmul', 'a@32', 0.0), 0.0, '!'+signed_zero_inf_nan_preserve_32),
(('imul', a, 0), 0),
(('umul_unorm_4x8', a, 0), 0),
(('umul_unorm_4x8', a, ~0), a),
@@ -165,6 +168,8 @@ optimizations = [
(('fmul', ('fsign', a), ('fmul', a, a)), ('fmul', ('fabs', a), a)),
(('fmul', ('fmul', ('fsign', a), a), a), ('fmul', ('fabs', a), a)),
(('~ffma', 0.0, a, b), b),
(('ffma@16(is_only_used_as_float)', 0.0, a, b), b, '!'+signed_zero_inf_nan_preserve_16),
(('ffma@32(is_only_used_as_float)', 0.0, a, b), b, '!'+signed_zero_inf_nan_preserve_32),
(('~ffma', a, b, 0.0), ('fmul', a, b)),
(('ffma@16', a, b, 0.0), ('fmul', a, b), '!'+signed_zero_inf_nan_preserve_16),
(('ffma@32', a, b, 0.0), ('fmul', a, b), '!'+signed_zero_inf_nan_preserve_32),