nir/algebraic: Recognize open-coded flrp(-1, 1, a) and flrp(1, -1, a)

v2: Remove flrp@64 cases.  Since Gen11 removes flrp@32, it seems
unlikely that we'll ever have a flrp@64.  Should that occur, the cases
can be added back.

v3: Add a couple more patterns that just move the negation around.

No shader-db changes Ice Lake, Iron Lake, or GM45 as these platforms
lack a LRP instruction.

Skylake
total instructions in shared programs: 15279687 -> 15256058 (-0.15%)
instructions in affected programs: 4344440 -> 4320811 (-0.54%)
helped: 23455
HURT: 18
helped stats (abs) min: 1 max: 21 x̄: 1.01 x̃: 1
helped stats (rel) min: 0.02% max: 13.33% x̄: 0.86% x̃: 0.65%
HURT stats (abs)   min: 1 max: 2 x̄: 1.06 x̃: 1
HURT stats (rel)   min: 0.13% max: 1.16% x̄: 0.43% x̃: 0.34%
95% mean confidence interval for instructions value: -1.01 -1.00
95% mean confidence interval for instructions %-change: -0.87% -0.85%
Instructions are helped.

total cycles in shared programs: 355593755 -> 355339981 (-0.07%)
cycles in affected programs: 162089552 -> 161835778 (-0.16%)
helped: 20467
HURT: 7158
helped stats (abs) min: 1 max: 2074 x̄: 29.00 x̃: 6
helped stats (rel) min: <.01% max: 35.71% x̄: 1.71% x̃: 0.58%
HURT stats (abs)   min: 1 max: 4814 x̄: 47.46 x̃: 11
HURT stats (rel)   min: <.01% max: 125.43% x̄: 2.88% x̃: 0.98%
95% mean confidence interval for cycles value: -10.39 -7.98
95% mean confidence interval for cycles %-change: -0.57% -0.47%
Cycles are helped.

total spills in shared programs: 8843 -> 8835 (-0.09%)
spills in affected programs: 190 -> 182 (-4.21%)
helped: 2
HURT: 0

total fills in shared programs: 21738 -> 21738 (0.00%)
fills in affected programs: 372 -> 372 (0.00%)
helped: 1
HURT: 1

LOST:   12
GAINED: 22

Broadwell
total instructions in shared programs: 15290523 -> 15266818 (-0.16%)
instructions in affected programs: 4314738 -> 4291033 (-0.55%)
helped: 23391
HURT: 11
helped stats (abs) min: 1 max: 119 x̄: 1.02 x̃: 1
helped stats (rel) min: 0.02% max: 13.33% x̄: 0.86% x̃: 0.65%
HURT stats (abs)   min: 1 max: 189 x̄: 18.09 x̃: 1
HURT stats (rel)   min: 0.11% max: 5.39% x̄: 0.98% x̃: 0.50%
95% mean confidence interval for instructions value: -1.04 -0.99
95% mean confidence interval for instructions %-change: -0.87% -0.85%
Instructions are helped.

total cycles in shared programs: 388911660 -> 388830827 (-0.02%)
cycles in affected programs: 172903324 -> 172822491 (-0.05%)
helped: 15601
HURT: 13269
helped stats (abs) min: 1 max: 1986 x̄: 29.18 x̃: 6
helped stats (rel) min: <.01% max: 36.60% x̄: 1.74% x̃: 0.55%
HURT stats (abs)   min: 1 max: 14904 x̄: 28.21 x̃: 6
HURT stats (rel)   min: <.01% max: 102.58% x̄: 1.77% x̃: 0.60%
95% mean confidence interval for cycles value: -4.20 -1.40
95% mean confidence interval for cycles %-change: -0.17% -0.08%
Cycles are helped.

total spills in shared programs: 23110 -> 23069 (-0.18%)
spills in affected programs: 656 -> 615 (-6.25%)
helped: 3
HURT: 1

total fills in shared programs: 34399 -> 34398 (<.01%)
fills in affected programs: 905 -> 904 (-0.11%)
helped: 3
HURT: 1

LOST:   6
GAINED: 23

Haswell
total instructions in shared programs: 13465303 -> 13441142 (-0.18%)
instructions in affected programs: 3726999 -> 3702838 (-0.65%)
helped: 22139
HURT: 347
helped stats (abs) min: 1 max: 43 x̄: 1.11 x̃: 1
helped stats (rel) min: 0.03% max: 10.00% x̄: 1.01% x̃: 0.75%
HURT stats (abs)   min: 1 max: 1 x̄: 1.00 x̃: 1
HURT stats (rel)   min: 0.35% max: 11.11% x̄: 1.48% x̃: 1.12%
95% mean confidence interval for instructions value: -1.08 -1.07
95% mean confidence interval for instructions %-change: -0.99% -0.96%
Instructions are helped.

total cycles in shared programs: 376271308 -> 376273090 (<.01%)
cycles in affected programs: 167496811 -> 167498593 (<.01%)
helped: 13206
HURT: 13281
helped stats (abs) min: 1 max: 3864 x̄: 35.39 x̃: 8
helped stats (rel) min: <.01% max: 53.10% x̄: 2.31% x̃: 0.80%
HURT stats (abs)   min: 1 max: 3828 x̄: 35.32 x̃: 8
HURT stats (rel)   min: <.01% max: 117.85% x̄: 2.88% x̃: 0.61%
95% mean confidence interval for cycles value: -1.33 1.47
95% mean confidence interval for cycles %-change: 0.22% 0.36%
Inconclusive result (value mean confidence interval includes 0).

total spills in shared programs: 23158 -> 23134 (-0.10%)
spills in affected programs: 24 -> 0
helped: 3
HURT: 0

total fills in shared programs: 34580 -> 34550 (-0.09%)
fills in affected programs: 30 -> 0
helped: 3
HURT: 0

LOST:   23
GAINED: 13

Ivy Bridge
total instructions in shared programs: 12034154 -> 12014301 (-0.16%)
instructions in affected programs: 3636209 -> 3616356 (-0.55%)
helped: 18771
HURT: 459
helped stats (abs) min: 1 max: 43 x̄: 1.08 x̃: 1
helped stats (rel) min: 0.03% max: 10.00% x̄: 0.91% x̃: 0.68%
HURT stats (abs)   min: 1 max: 1 x̄: 1.00 x̃: 1
HURT stats (rel)   min: 0.34% max: 8.33% x̄: 1.43% x̃: 1.11%
95% mean confidence interval for instructions value: -1.04 -1.02
95% mean confidence interval for instructions %-change: -0.86% -0.84%
Instructions are helped.

total cycles in shared programs: 180186960 -> 180175147 (<.01%)
cycles in affected programs: 44652745 -> 44640932 (-0.03%)
helped: 12979
HURT: 11033
helped stats (abs) min: 1 max: 5836 x̄: 32.88 x̃: 6
helped stats (rel) min: <.01% max: 53.10% x̄: 2.19% x̃: 0.74%
HURT stats (abs)   min: 1 max: 4811 x̄: 37.61 x̃: 9
HURT stats (rel)   min: <.01% max: 115.18% x̄: 2.99% x̃: 0.69%
95% mean confidence interval for cycles value: -2.29 1.31
95% mean confidence interval for cycles %-change: 0.11% 0.26%
Inconclusive result (value mean confidence interval includes 0).

total spills in shared programs: 3623 -> 3599 (-0.66%)
spills in affected programs: 24 -> 0
helped: 3
HURT: 0

total fills in shared programs: 4061 -> 4031 (-0.74%)
fills in affected programs: 30 -> 0
helped: 3
HURT: 0

LOST:   17
GAINED: 18

Sandy Bridge
total instructions in shared programs: 10853968 -> 10834932 (-0.18%)
instructions in affected programs: 3769957 -> 3750921 (-0.50%)
helped: 17944
HURT: 204
helped stats (abs) min: 1 max: 3 x̄: 1.07 x̃: 1
helped stats (rel) min: 0.02% max: 10.00% x̄: 0.83% x̃: 0.60%
HURT stats (abs)   min: 1 max: 2 x̄: 1.01 x̃: 1
HURT stats (rel)   min: 0.31% max: 9.09% x̄: 1.83% x̃: 0.93%
95% mean confidence interval for instructions value: -1.05 -1.04
95% mean confidence interval for instructions %-change: -0.81% -0.78%
Instructions are helped.

total cycles in shared programs: 153894864 -> 153885988 (<.01%)
cycles in affected programs: 50643925 -> 50635049 (-0.02%)
helped: 9361
HURT: 10534
helped stats (abs) min: 1 max: 1966 x̄: 19.42 x̃: 4
helped stats (rel) min: <.01% max: 34.97% x̄: 0.90% x̃: 0.22%
HURT stats (abs)   min: 1 max: 1371 x̄: 16.42 x̃: 5
HURT stats (rel)   min: <.01% max: 55.10% x̄: 0.81% x̃: 0.27%
95% mean confidence interval for cycles value: -1.27 0.38
95% mean confidence interval for cycles %-change: -0.03% 0.04%
Inconclusive result (value mean confidence interval includes 0).

LOST:   6
GAINED: 24

Reviewed-by: Matt Turner <[email protected]>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index 771a8247430..fa940429281 100644
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -1233,6 +1233,18 @@ late_optimizations = [
    (('~fadd@32', 1.0, ('fmul(is_used_once)', c , ('fadd', b, -1.0 ))), ('fadd', ('fadd', 1.0, ('fneg', c)), ('fmul', b, c)), 'options->lower_flrp32'),
    (('~fadd@64', 1.0, ('fmul(is_used_once)', c , ('fadd', b, -1.0 ))), ('fadd', ('fadd', 1.0, ('fneg', c)), ('fmul', b, c)), 'options->lower_flrp64'),
 
+   # A similar operation could apply to any ffma(#a, b, #(-a/2)), but this
+   # particular operation is common for expanding values stored in a texture
+   # from [0,1] to [-1,1].
+   (('~ffma@32', a,  2.0, -1.0), ('flrp', -1.0,  1.0,          a ), '!options->lower_flrp32'),
+   (('~ffma@32', a, -2.0, -1.0), ('flrp', -1.0,  1.0, ('fneg', a)), '!options->lower_flrp32'),
+   (('~ffma@32', a, -2.0,  1.0), ('flrp',  1.0, -1.0,          a ), '!options->lower_flrp32'),
+   (('~ffma@32', a,  2.0,  1.0), ('flrp',  1.0, -1.0, ('fneg', a)), '!options->lower_flrp32'),
+   (('~fadd@32', ('fmul(is_used_once)',  2.0, a), -1.0), ('flrp', -1.0,  1.0,          a ), '!options->lower_flrp32'),
+   (('~fadd@32', ('fmul(is_used_once)', -2.0, a), -1.0), ('flrp', -1.0,  1.0, ('fneg', a)), '!options->lower_flrp32'),
+   (('~fadd@32', ('fmul(is_used_once)', -2.0, a),  1.0), ('flrp',  1.0, -1.0,          a ), '!options->lower_flrp32'),
+   (('~fadd@32', ('fmul(is_used_once)',  2.0, a),  1.0), ('flrp',  1.0, -1.0, ('fneg', a)), '!options->lower_flrp32'),
+
    # we do these late so that we don't get in the way of creating ffmas
    (('fmin', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmin', a, b))),
    (('fmax', ('fadd(is_used_once)', '#c', a), ('fadd(is_used_once)', '#c', b)), ('fadd', c, ('fmax', a, b))),