nir/algebraic: Use value range analysis to eliminate tautological compares

It's only one application on one platform (Haswell) that's affected,
but spills and fills increase quite dramatically. :(

All Gen8+ platforms had similar results. (Ice Lake shown)
total instructions in shared programs: 16320850 -> 16297320 (-0.14%)
instructions in affected programs: 448012 -> 424482 (-5.25%)
helped: 1938
HURT: 0
helped stats (abs) min: 2 max: 264 x̄: 12.14 x̃: 10
helped stats (rel) min: 0.35% max: 43.75% x̄: 5.85% x̃: 5.38%
95% mean confidence interval for instructions value: -12.80 -11.48
95% mean confidence interval for instructions %-change: -5.99% -5.72%
Instructions are helped.

total cycles in shared programs: 367496943 -> 367221624 (-0.07%)
cycles in affected programs: 8557232 -> 8281913 (-3.22%)
helped: 1907
HURT: 26
helped stats (abs) min: 4 max: 12802 x̄: 147.21 x̃: 48
helped stats (rel) min: 0.03% max: 75.85% x̄: 5.55% x̃: 3.94%
HURT stats (abs)   min: 4 max: 1870 x̄: 208.23 x̃: 20
HURT stats (rel)   min: 0.16% max: 32.11% x̄: 8.31% x̃: 0.79%
95% mean confidence interval for cycles value: -165.38 -119.48
95% mean confidence interval for cycles %-change: -5.68% -5.04%
Cycles are helped.

LOST:   1
GAINED: 0

Haswell
total instructions in shared programs: 13374211 -> 13353925 (-0.15%)
instructions in affected programs: 349868 -> 329582 (-5.80%)
helped: 1669
HURT: 1
helped stats (abs) min: 1 max: 264 x̄: 12.57 x̃: 10
helped stats (rel) min: 0.12% max: 46.81% x̄: 6.86% x̃: 6.49%
HURT stats (abs)   min: 700 max: 700 x̄: 700.00 x̃: 700
HURT stats (rel)   min: 64.34% max: 64.34% x̄: 64.34% x̃: 64.34%
95% mean confidence interval for instructions value: -13.25 -11.04
95% mean confidence interval for instructions %-change: -7.01% -6.63%
Instructions are helped.

total cycles in shared programs: 375763544 -> 375535444 (-0.06%)
cycles in affected programs: 6932686 -> 6704586 (-3.29%)
helped: 1622
HURT: 48
helped stats (abs) min: 2 max: 12229 x̄: 148.31 x̃: 68
helped stats (rel) min: 0.06% max: 74.03% x̄: 5.94% x̃: 4.12%
HURT stats (abs)   min: 3 max: 7451 x̄: 259.44 x̃: 41
HURT stats (rel)   min: 0.05% max: 54.99% x̄: 8.52% x̃: 2.88%
95% mean confidence interval for cycles value: -159.86 -113.31
95% mean confidence interval for cycles %-change: -5.86% -5.18%
Cycles are helped.

total spills in shared programs: 23258 -> 23401 (0.61%)
spills in affected programs: 54 -> 197 (264.81%)
helped: 4
HURT: 2

total fills in shared programs: 34775 -> 34850 (0.22%)
fills in affected programs: 52 -> 127 (144.23%)
helped: 4
HURT: 1

LOST:   5
GAINED: 0

Ivy Bridge
total instructions in shared programs: 11996051 -> 11977964 (-0.15%)
instructions in affected programs: 346679 -> 328592 (-5.22%)
helped: 1508
HURT: 0
helped stats (abs) min: 2 max: 198 x̄: 11.99 x̃: 10
helped stats (rel) min: 0.26% max: 19.83% x̄: 5.73% x̃: 5.43%
95% mean confidence interval for instructions value: -12.65 -11.34
95% mean confidence interval for instructions %-change: -5.86% -5.60%
Instructions are helped.

total cycles in shared programs: 179891389 -> 179691339 (-0.11%)
cycles in affected programs: 7869479 -> 7669429 (-2.54%)
helped: 1485
HURT: 23
helped stats (abs) min: 1 max: 12615 x̄: 136.16 x̃: 54
helped stats (rel) min: 0.02% max: 71.84% x̄: 4.69% x̃: 3.49%
HURT stats (abs)   min: 1 max: 403 x̄: 93.48 x̃: 6
HURT stats (rel)   min: 0.04% max: 34.01% x̄: 8.68% x̃: 0.81%
95% mean confidence interval for cycles value: -154.59 -110.73
95% mean confidence interval for cycles %-change: -4.79% -4.19%
Cycles are helped.

Sandy Bridge
total instructions in shared programs: 10829247 -> 10828844 (<.01%)
instructions in affected programs: 21258 -> 20855 (-1.90%)
helped: 88
HURT: 0
helped stats (abs) min: 2 max: 17 x̄: 4.58 x̃: 5
helped stats (rel) min: 0.52% max: 3.92% x̄: 2.05% x̃: 2.21%
95% mean confidence interval for instructions value: -5.03 -4.13
95% mean confidence interval for instructions %-change: -2.21% -1.89%
Instructions are helped.

total cycles in shared programs: 154035437 -> 154024591 (<.01%)
cycles in affected programs: 430176 -> 419330 (-2.52%)
helped: 78
HURT: 10
helped stats (abs) min: 2 max: 4649 x̄: 143.06 x̃: 32
helped stats (rel) min: 0.05% max: 6.02% x̄: 2.03% x̃: 1.07%
HURT stats (abs)   min: 3 max: 265 x̄: 31.30 x̃: 6
HURT stats (rel)   min: 0.10% max: 8.67% x̄: 1.03% x̃: 0.21%
95% mean confidence interval for cycles value: -232.53 -13.97
95% mean confidence interval for cycles %-change: -2.13% -1.23%
Cycles are helped.

Iron Lake and GM45 had similar results. (Iron Lake shown)
total instructions in shared programs: 8137402 -> 8137248 (<.01%)
instructions in affected programs: 2280 -> 2126 (-6.75%)
helped: 10
HURT: 0
helped stats (abs) min: 12 max: 19 x̄: 15.40 x̃: 15
helped stats (rel) min: 3.90% max: 11.73% x̄: 7.19% x̃: 6.95%
95% mean confidence interval for instructions value: -17.69 -13.11
95% mean confidence interval for instructions %-change: -8.99% -5.39%
Instructions are helped.

total cycles in shared programs: 188538716 -> 188583424 (0.02%)
cycles in affected programs: 69326 -> 114034 (64.49%)
helped: 0
HURT: 10
HURT stats (abs)   min: 2068 max: 7686 x̄: 4470.80 x̃: 4870
HURT stats (rel)   min: 27.20% max: 173.66% x̄: 69.55% x̃: 59.41%
95% mean confidence interval for cycles value: 2830.86 6110.74
95% mean confidence interval for cycles %-change: 39.18% 99.91%
Cycles are HURT.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>

diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index d3f6c196e3bca445c97e62cd95389b445b5a9337..0711f491a4c543e6d10c544eddb6faea11543399 100644 (file)
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -798,33 +798,33 @@ optimizations = [
    (('fmax', ('fadd', ('fmul', ('fsat', a), ('fneg', ('fsat', a))), 1.0), 0.0), ('fadd', ('fmul', ('fsat', a), ('fneg', ('fsat', a))), 1.0)),
    (('fmax', ('fadd', ('fneg', ('fmul', ('fsat', a), ('fsat', a))), 1.0), 0.0), ('fadd', ('fneg', ('fmul', ('fsat', a), ('fsat', a))), 1.0)),
 
-   (('fne(is_not_used_by_if)', 'a(is_not_zero)', 0.0), True),
-   (('feq(is_not_used_by_if)', 'a(is_not_zero)', 0.0), False),
+   (('fne', 'a(is_not_zero)', 0.0), True),
+   (('feq', 'a(is_not_zero)', 0.0), False),
 
-   (('fge(is_not_used_by_if)', 'a(is_not_negative)', 'b(is_not_positive)'), True),
-   (('fge(is_not_used_by_if)', 'b(is_not_positive)', 'a(is_gt_zero)'),      False),
-   (('fge(is_not_used_by_if)', 'a(is_lt_zero)',      'b(is_not_negative)'), False),
-   (('fge(is_not_used_by_if)', 'b(is_not_negative)', 'a(is_not_positive)'), True),
+   (('fge', 'a(is_not_negative)', 'b(is_not_positive)'), True),
+   (('fge', 'b(is_not_positive)', 'a(is_gt_zero)'),      False),
+   (('fge', 'a(is_lt_zero)',      'b(is_not_negative)'), False),
+   (('fge', 'b(is_not_negative)', 'a(is_not_positive)'), True),
 
-   (('flt(is_not_used_by_if)', 'a(is_not_negative)', 'b(is_not_positive)'), False),
-   (('flt(is_not_used_by_if)', 'b(is_not_positive)', 'a(is_gt_zero)'),      True),
-   (('flt(is_not_used_by_if)', 'a(is_lt_zero)',      'b(is_not_negative)'), True),
-   (('flt(is_not_used_by_if)', 'b(is_not_negative)', 'a(is_not_positive)'), False),
+   (('flt', 'a(is_not_negative)', 'b(is_not_positive)'), False),
+   (('flt', 'b(is_not_positive)', 'a(is_gt_zero)'),      True),
+   (('flt', 'a(is_lt_zero)',      'b(is_not_negative)'), True),
+   (('flt', 'b(is_not_negative)', 'a(is_not_positive)'), False),
 
-   (('ine(is_not_used_by_if)', 'a(is_not_zero)', 0), True),
-   (('ieq(is_not_used_by_if)', 'a(is_not_zero)', 0), False),
+   (('ine', 'a(is_not_zero)', 0), True),
+   (('ieq', 'a(is_not_zero)', 0), False),
 
-   (('ige(is_not_used_by_if)', 'a(is_not_negative)', 'b(is_not_positive)'), True),
-   (('ige(is_not_used_by_if)', 'b(is_not_positive)', 'a(is_gt_zero)'),      False),
-   (('ige(is_not_used_by_if)', 'a(is_lt_zero)',      'b(is_not_negative)'), False),
-   (('ige(is_not_used_by_if)', 'b(is_not_negative)', 'a(is_not_positive)'), True),
+   (('ige', 'a(is_not_negative)', 'b(is_not_positive)'), True),
+   (('ige', 'b(is_not_positive)', 'a(is_gt_zero)'),      False),
+   (('ige', 'a(is_lt_zero)',      'b(is_not_negative)'), False),
+   (('ige', 'b(is_not_negative)', 'a(is_not_positive)'), True),
 
-   (('ilt(is_not_used_by_if)', 'a(is_not_negative)', 'b(is_not_positive)'), False),
-   (('ilt(is_not_used_by_if)', 'b(is_not_positive)', 'a(is_gt_zero)'),      True),
-   (('ilt(is_not_used_by_if)', 'a(is_lt_zero)',      'b(is_not_negative)'), True),
-   (('ilt(is_not_used_by_if)', 'b(is_not_negative)', 'a(is_not_positive)'), False),
+   (('ilt', 'a(is_not_negative)', 'b(is_not_positive)'), False),
+   (('ilt', 'b(is_not_positive)', 'a(is_gt_zero)'),      True),
+   (('ilt', 'a(is_lt_zero)',      'b(is_not_negative)'), True),
+   (('ilt', 'b(is_not_negative)', 'a(is_not_positive)'), False),
 
-   (('ult(is_not_used_by_if)', 0, 'a(is_gt_zero)'), True),
+   (('ult', 0, 'a(is_gt_zero)'), True),
 
    # Packing and then unpacking does nothing
    (('unpack_64_2x32_split_x', ('pack_64_2x32_split', a, b)), a),