[llvm-commits] [llvm] r40722 - in /llvm/trunk: include/llvm/CodeGen/SelectionDAGNodes.h lib/CodeGen/SelectionDAG/ScheduleDAG.cpp lib/CodeGen/SelectionDAG/SelectionDAG.cpp

[Evan Cheng]

Author: evancheng
Date: Thu Aug  2 00:29:38 2007
New Revision: 40722

URL: http://llvm.org/viewvc/llvm-project?rev=40722&view=rev
Log:
Do not emit copies for physical register output if it's not used.

Modified:
    llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h
    llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

Modified: llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h
URL: 
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h?rev=40722&r1=40721&r2=40722&view=diff

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h (original)
+++ llvm/trunk/include/llvm/CodeGen/SelectionDAGNodes.h Thu Aug  2 00:29:38 2007
@@ -858,6 +858,10 @@
   /// operation.
   bool hasNUsesOfValue(unsigned NUses, unsigned Value) const;
 
+  /// hasAnyUseOfValue - Return true if there are any use of the indicated
+  /// value. This method ignores uses of other values defined by this 
operation.
+  bool hasAnyUseOfValue(unsigned Value) const;
+
   /// isOnlyUse - Return true if this node is the only use of N.
   ///
   bool isOnlyUse(SDNode *N) const;

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp
URL: 
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp?rev=40722&r1=40721&r2=40722&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp Thu Aug  2 00:29:38 2007
@@ -676,7 +676,8 @@
     if (HasPhysRegOuts) {
       for (unsigned i = II.numDefs; i < NumResults; ++i) {
         unsigned Reg = II.ImplicitDefs[i - II.numDefs];
-        EmitCopyFromReg(Node, i, Reg, VRBaseMap);
+        if (Node->hasAnyUseOfValue(i))
+          EmitCopyFromReg(Node, i, Reg, VRBaseMap);
       }
     }
   } else {

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
URL: 
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp?rev=40722&r1=40721&r2=40722&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAG.cpp Thu Aug  2 00:29:38 
2007
@@ -3242,7 +3242,7 @@
   // If there is only one value, this is easy.
   if (getNumValues() == 1)
     return use_size() == NUses;
-  if (Uses.size() < NUses) return false;
+  if (use_size() < NUses) return false;
 
   SDOperand TheValue(const_cast<SDNode *>(this), Value);
 
@@ -3265,6 +3265,31 @@
 }
 
 
+/// hasAnyUseOfValue - Return true if there are any use of the indicated
+/// value. This method ignores uses of other values defined by this operation.
+bool SDNode::hasAnyUseOfValue(unsigned Value) const {
+  assert(Value < getNumValues() && "Bad value!");
+
+  if (use_size() == 0) return false;
+
+  SDOperand TheValue(const_cast<SDNode *>(this), Value);
+
+  SmallPtrSet<SDNode*, 32> UsersHandled;
+
+  for (SDNode::use_iterator UI = Uses.begin(), E = Uses.end(); UI != E; ++UI) {
+    SDNode *User = *UI;
+    if (User->getNumOperands() == 1 ||
+        UsersHandled.insert(User))     // First time we've seen this?
+      for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i)
+        if (User->getOperand(i) == TheValue) {
+          return true;
+        }
+  }
+
+  return false;
+}
+
+
 /// isOnlyUse - Return true if this node is the only use of N.
 ///
 bool SDNode::isOnlyUse(SDNode *N) const {


_______________________________________________
llvm-commits mailing list
llvm-commits@cs.uiuc.edu
http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits