Mesa (main): aco/ra: only create phi-affinities for killed operands

[GitLab Mirror]

Module: Mesa
Branch: main
Commit: 3a98f484d146d31065794a2091fcddf584b1cb46
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=3a98f484d146d31065794a2091fcddf584b1cb46

Author: Daniel Schürmann <daniel at schuermann.dev>
Date:   Thu Jan 28 16:52:28 2021 +0100

aco/ra: only create phi-affinities for killed operands

If a phi-operand is not killed, it must be copied anyway.
The additional affinity would only overwrite any potential
better affinity that was already created

Totals from 1067 (0.71% of 149839) affected shaders (GFX10.3):
VGPRs: 68072 -> 68064 (-0.01%)
CodeSize: 8252588 -> 8245220 (-0.09%); split: -0.12%, +0.03%
Instrs: 1596146 -> 1593941 (-0.14%); split: -0.16%, +0.02%
Latency: 18828176 -> 18823914 (-0.02%); split: -0.08%, +0.06%
InvThroughput: 3575063 -> 3574787 (-0.01%); split: -0.05%, +0.04%
VClause: 24345 -> 24325 (-0.08%); split: -0.16%, +0.07%
Copies: 88712 -> 87398 (-1.48%); split: -1.77%, +0.29%
Branches: 52067 -> 51364 (-1.35%); split: -1.38%, +0.03%

Reviewed-by: Tony Wasserka <tony.wasserka at gmx.de>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8764>

---

 src/amd/compiler/aco_register_allocation.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/amd/compiler/aco_register_allocation.cpp b/src/amd/compiler/aco_register_allocation.cpp
index 8b1d662ff69..736c3e786c6 100644
--- a/src/amd/compiler/aco_register_allocation.cpp
+++ b/src/amd/compiler/aco_register_allocation.cpp
@@ -2055,7 +2055,7 @@ void get_affinities(ra_ctx& ctx, std::vector<IDSet>& live_out_per_block)
             affinity_related.emplace_back(instr->definitions[0].getTemp());
             affinity_related.emplace_back(instr->definitions[0].getTemp());
             for (const Operand& op : instr->operands) {
-               if (op.isTemp() && op.regClass() == instr->definitions[0].regClass()) {
+               if (op.isTemp() && op.isKill() && op.regClass() == instr->definitions[0].regClass()) {
                   affinity_related.emplace_back(op.getTemp());
                   temp_to_phi_ressources[op.tempId()] = phi_ressources.size();
                }