Mesa (staging/21.2): pan/bi: Remove incorrect errata workaround

[GitLab Mirror]

Module: Mesa
Branch: staging/21.2
Commit: 538e9f93c5f842c7ff749103bc80329d81f8a583
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=538e9f93c5f842c7ff749103bc80329d81f8a583

Author: Alyssa Rosenzweig <alyssa at collabora.com>
Date:   Wed Jul 28 14:34:34 2021 -0400

pan/bi: Remove incorrect errata workaround

This worked around a symptom of the underlying issue worked around in
the previous commit. This workaround is wrong in the sense of failing to
correct some broken code sequences and needlessly rejecting some working
code sequences.

total tuples in shared programs: 123770 -> 123630 (-0.11%)
tuples in affected programs: 9548 -> 9408 (-1.47%)
helped: 133
HURT: 0
helped stats (abs) min: 1.0 max: 2.0 x̄: 1.05 x̃: 1
helped stats (rel) min: 0.42% max: 16.67% x̄: 4.07% x̃: 1.15%
95% mean confidence interval for tuples value: -1.09 -1.01
95% mean confidence interval for tuples %-change: -4.98% -3.17%
Tuples are helped.

total cycles in shared programs: 12114.83 -> 12114.50 (<.01%)
cycles in affected programs: 34.08 -> 33.75 (-0.98%)
helped: 9
HURT: 1
helped stats (abs) min: 0.04166599999999998 max: 0.04166700000000034 x̄: 0.04 x̃: 0
helped stats (rel) min: 0.72% max: 12.50% x̄: 2.99% x̃: 2.04%
HURT stats (abs)   min: 0.04166700000000034 max: 0.04166700000000034 x̄: 0.04 x̃: 0
HURT stats (rel)   min: 0.62% max: 0.62% x̄: 0.62% x̃: 0.62%
95% mean confidence interval for cycles value: -0.05 -0.01
95% mean confidence interval for cycles %-change: -5.27% <.01%
Inconclusive result (%-change mean confidence interval includes 0).

total arith in shared programs: 4603.42 -> 4601.54 (-0.04%)
arith in affected programs: 50.50 -> 48.62 (-3.71%)
helped: 41
HURT: 1
helped stats (abs) min: 0.04166599999999998 max: 0.08333299999999999 x̄: 0.05 x̃: 0
helped stats (rel) min: 0.72% max: 33.33% x̄: 17.23% x̃: 13.33%
HURT stats (abs)   min: 0.04166700000000034 max: 0.04166700000000034 x̄: 0.04 x̃: 0
HURT stats (rel)   min: 0.62% max: 0.62% x̄: 0.62% x̃: 0.62%
95% mean confidence interval for arith value: -0.05 -0.04
95% mean confidence interval for arith %-change: -20.93% -12.69%
Arith are helped.

total quadwords in shared programs: 110116 -> 110009 (-0.10%)
quadwords in affected programs: 7829 -> 7722 (-1.37%)
helped: 106
HURT: 0
helped stats (abs) min: 1.0 max: 2.0 x̄: 1.01 x̃: 1
helped stats (rel) min: 0.49% max: 7.14% x̄: 1.91% x̃: 1.35%
95% mean confidence interval for quadwords value: -1.03 -0.99
95% mean confidence interval for quadwords %-change: -2.23% -1.59%
Quadwords are helped.

Signed-off-by: Alyssa Rosenzweig <alyssa at collabora.com>
Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12114>
(cherry picked from commit be7d964ff03d1c08ab3aac1452d7377a590f91e3)

---

 .pick_status.json                  | 2 +-
 src/panfrost/bifrost/bi_schedule.c | 6 ------
 2 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/.pick_status.json b/.pick_status.json
index b3eb881900c..b9134e64d42 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -220,7 +220,7 @@
         "description": "pan/bi: Remove incorrect errata workaround",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null
     },
diff --git a/src/panfrost/bifrost/bi_schedule.c b/src/panfrost/bifrost/bi_schedule.c
index bdfbae7e012..4caf78547eb 100644
--- a/src/panfrost/bifrost/bi_schedule.c
+++ b/src/panfrost/bifrost/bi_schedule.c
@@ -507,12 +507,6 @@ bi_can_iaddc(bi_instr *ins)
 ASSERTED static bool
 bi_can_fma(bi_instr *ins)
 {
-        /* Errata: *V2F32_TO_V2F16 with distinct sources raises
-         * INSTR_INVALID_ENC under certain conditions */
-        if (ins->op == BI_OPCODE_V2F32_TO_V2F16 &&
-                        !bi_is_word_equiv(ins->src[0], ins->src[1]))
-                return false;
-
         /* +IADD.i32 -> *IADDC.i32 */
         if (bi_can_iaddc(ins))
                 return true;