nvc0/ir: don't dual-issue ops that depend or interfere with each other

Signed-off-by: Karol Herbst <karolherbst@gmail.com>
Reviewed-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
[imirkin: rewrite to split up the helpers and move more logic to target]
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nvc0.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nvc0.cpp
index 04ac288..0cb21e8 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nvc0.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nvc0.cpp
@@ -615,6 +615,12 @@ bool TargetNVC0::canDualIssue(const Instruction *a, const Instruction *b) const
       // not if the 2nd instruction isn't necessarily executed
       if (clA == OPCLASS_TEXTURE || clA == OPCLASS_FLOW)
          return false;
+
+      // Check that a and b don't write to the same sources, nor that b reads
+      // anything that a writes.
+      if (!a->canCommuteDefDef(b) || !a->canCommuteDefSrc(b))
+         return false;
+
       // anything with MOV
       if (a->op == OP_MOV || b->op == OP_MOV)
          return true;