[llvm-commits] [llvm] r157147 - /llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Sat May 19 23:52:48 2012
New Revision: 157147

URL: http://llvm.org/viewvc/llvm-project?rev=157147&view=rev
Log:
Avoid deleting extra copies when RegistersDefinedFromSameValue is true.

This function adds copies to be erased to DupCopies, avoid also adding
them to DeadCopies.

Modified:
    llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp

Modified: llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp?rev=157147&r1=157146&r2=157147&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp Sat May 19 23:52:48 2012
@@ -1310,9 +1310,10 @@
 
     // DstReg is known to be a register in the LHS interval.  If the src is
     // from the RHS interval, we can use its value #.
-    if (!CP.isCoalescable(MI) &&
-        !RegistersDefinedFromSameValue(*LIS, *TRI, CP, VNI, OtherVNI,
-                                       DupCopies))
+    if (CP.isCoalescable(MI))
+      DeadCopies.push_back(MI);
+    else if (!RegistersDefinedFromSameValue(*LIS, *TRI, CP, VNI, OtherVNI,
+                                            DupCopies))
       continue;
 
     LHSValsDefinedFromRHS[VNI] = OtherVNI;
@@ -1339,13 +1340,13 @@
 
     // DstReg is known to be a register in the RHS interval.  If the src is
     // from the LHS interval, we can use its value #.
-    if (!CP.isCoalescable(MI) &&
-        !RegistersDefinedFromSameValue(*LIS, *TRI, CP, VNI, OtherVNI,
-                                       DupCopies))
+    if (CP.isCoalescable(MI))
+      DeadCopies.push_back(MI);
+    else if (!RegistersDefinedFromSameValue(*LIS, *TRI, CP, VNI, OtherVNI,
+                                            DupCopies))
         continue;
 
     RHSValsDefinedFromLHS[VNI] = OtherVNI;
-    DeadCopies.push_back(MI);
   }
 
   LHSValNoAssignments.resize(LHS.getNumValNums(), -1);