commit 8cccf0ef0ced7f4d75ca574b596036a9b6cd4315
author Dan Gohman <gohman@apple.com> Mon Mar 23 17:39:36 2009 +0000
committer Dan Gohman <gohman@apple.com> Mon Mar 23 17:39:36 2009 +0000
tree f4320254eda5b94ffed22421f4aa5ceb2fbc8179
parent a5c8ae233ebaef270b8fa96565ca7bf4fdcb3e15

Don't set SUnit::hasPhysRegDefs to true unless the defs are
actually have uses, which reflects the way it's used.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67540 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
index 303f8cc..7aa15bc 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
@@ -175,7 +175,10 @@
       if (N->isMachineOpcode() &&
           TII->get(N->getMachineOpcode()).getImplicitDefs()) {
         SU->hasPhysRegClobbers = true;
-        if (CountResults(N) > TII->get(N->getMachineOpcode()).getNumDefs())
+        unsigned NumUsed = CountResults(N);
+        while (NumUsed != 0 && !N->hasAnyUseOfValue(NumUsed - 1))
+          --NumUsed;    // Skip over unused values at the end.
+        if (NumUsed > TII->get(N->getMachineOpcode()).getNumDefs())
           SU->hasPhysRegDefs = true;
       }