"stability issues", apparently: https://reviews.llvm.org/D103348
fossil-db (Navi10):
Totals from 4512 (3.01% of 149839) affected shaders:
VGPRs: 221516 -> 223308 (+0.81%); split: -0.07%, +0.88%
CodeSize:
23000080 ->
23070672 (+0.31%); split: -0.08%, +0.39%
MaxWaves: 107718 -> 107496 (-0.21%); split: +0.11%, -0.32%
Instrs: 4321890 -> 4362822 (+0.95%); split: -0.00%, +0.95%
Latency:
71495710 ->
71581476 (+0.12%); split: -0.07%, +0.19%
InvThroughput:
11858568 ->
11938960 (+0.68%); split: -0.00%, +0.68%
VClause: 76575 -> 76585 (+0.01%); split: -0.05%, +0.07%
SClause: 168771 -> 168709 (-0.04%); split: -0.06%, +0.02%
Copies: 182305 -> 221948 (+21.75%); split: -0.00%, +21.75%
PreVGPRs: 194657 -> 195635 (+0.50%); split: -0.00%, +0.50%
Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Fixes:
c353895c922 ("aco: use non-sequential addressing")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10898>
### NSAClauseBug
"MIMG-NSA in a hard clause has unpredictable results on GFX10.1"
+
+### NSAMaxSize5
+
+NSA MIMG instructions should be limited to 3 dwords before GFX10.3 to avoid
+stability issues: https://reviews.llvm.org/D103348
unsigned wqm_mask=0,
Operand vdata=Operand(v1))
{
- if (bld.program->chip_class < GFX10) {
+ /* Limit NSA instructions to 3 dwords on GFX10 to avoid stability issues. */
+ unsigned max_nsa_size = bld.program->chip_class >= GFX10_3 ? 13 : 5;
+ bool use_nsa = bld.program->chip_class >= GFX10 && coords.size() <= max_nsa_size;
+
+ if (!use_nsa) {
Temp coord = coords[0];
if (coords.size() > 1) {
coord = bld.tmp(RegType::vgpr, coords.size());