From: Rhys Perry <pendingchaos02@gmail.com>
Date: Sat, 21 Sep 2019 15:00:45 +0000 (+0100)
Subject: aco: don't CSE v_readlane_b32/v_readfirstlane_b32
X-Git-Tag: upstream/19.3.0~1618
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=86ecf92c23ccd4a5493a27104e9c85b8fa41f3a3;p=platform%2Fupstream%2Fmesa.git

aco: don't CSE v_readlane_b32/v_readfirstlane_b32

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
---

diff --git a/src/amd/compiler/aco_opt_value_numbering.cpp b/src/amd/compiler/aco_opt_value_numbering.cpp
index 8071ace..100537f 100644
--- a/src/amd/compiler/aco_opt_value_numbering.cpp
+++ b/src/amd/compiler/aco_opt_value_numbering.cpp
@@ -82,6 +82,10 @@ struct InstrPred {
          return false;
       if (a->operands.size() != b->operands.size() || a->definitions.size() != b->definitions.size())
          return false; /* possible with pseudo-instructions */
+      /* We can't value number v_readlane_b32 across control flow or discards
+       * because of the possibility of live-range splits. */
+      if (a->opcode == aco_opcode::v_readfirstlane_b32 || a->opcode == aco_opcode::v_readlane_b32)
+         return false;
       for (unsigned i = 0; i < a->operands.size(); i++) {
          if (a->operands[i].isConstant()) {
             if (!b->operands[i].isConstant())