[Mesa-dev] nv50/ir: avoid deleting pseudo instructions too early

Submitted by Ilia Mirkin on Sept. 25, 2014, 1:47 a.m.

Details

Message ID 1411609675-17670-1-git-send-email-imirkin@alum.mit.edu
State Accepted
Commit 0147c10c5f00b43696ba660aab604d674a75e83c
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Commit Message

Ilia Mirkin Sept. 25, 2014, 1:47 a.m.
What happens is that a SPLIT operation is part of the spill node, and as
a pseudo op, the instruction gets erased after processing its first def.
However the later defs still need to refer to it, so instead delay
spilling until after that whole RA node is done processing.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79462
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: "10.2 10.3" <mesa-stable@lists.freedesktop.org>
---
 src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

Patch hide | download patch | download mbox

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp
index 4b105b4..d47fed2 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_ra.cpp
@@ -25,6 +25,7 @@ 
 
 #include <stack>
 #include <limits>
+#include <tr1/unordered_set>
 
 namespace nv50_ir {
 
@@ -1547,6 +1548,11 @@  SpillCodeInserter::run(const std::list<ValuePair>& lst)
       LValue *lval = it->first->asLValue();
       Symbol *mem = it->second ? it->second->asSym() : NULL;
 
+      // Keep track of which instructions to delete later. Deleting them
+      // inside the loop is unsafe since a single instruction may have
+      // multiple destinations that all need to be spilled (like OP_SPLIT).
+      std::tr1::unordered_set<Instruction *> to_del;
+
       for (Value::DefIterator d = lval->defs.begin(); d != lval->defs.end();
            ++d) {
          Value *slot = mem ?
@@ -1579,7 +1585,7 @@  SpillCodeInserter::run(const std::list<ValuePair>& lst)
             d = lval->defs.erase(d);
             --d;
             if (slot->reg.file == FILE_MEMORY_LOCAL)
-               delete_Instruction(func->getProgram(), defi);
+               to_del.insert(defi);
             else
                defi->setDef(0, slot);
          } else {
@@ -1587,6 +1593,9 @@  SpillCodeInserter::run(const std::list<ValuePair>& lst)
          }
       }
 
+      for (std::tr1::unordered_set<Instruction *>::const_iterator it = to_del.begin();
+           it != to_del.end(); ++it)
+         delete_Instruction(func->getProgram(), *it);
    }
 
    // TODO: We're not trying to reuse old slots in a potential next iteration.