[llvm-commits] [llvm] r85654 - /llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

[Dan Gohman]

Author: djg
Date: Sat Oct 31 09:14:04 2009
New Revision: 85654

URL: http://llvm.org/viewvc/llvm-project?rev=85654&view=rev
Log:
When discarding SrcValue information, discard all of it so that code
that uses this information knows to behave conservatively.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=85654&r1=85653&r2=85654&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Sat Oct 31 09:14:04 2009
@@ -5730,9 +5730,9 @@
 
       // If this is an EXTLOAD, the VT's must match.
       if (LLD->getMemoryVT() == RLD->getMemoryVT()) {
-        // FIXME: this conflates two src values, discarding one.  This is not
-        // the right thing to do, but nothing uses srcvalues now.  When they do,
-        // turn SrcValue into a list of locations.
+        // FIXME: this discards src value information.  This is
+        // over-conservative. It would be beneficial to be able to remember
+        // both potential memory locations.
         SDValue Addr;
         if (TheSelect->getOpcode() == ISD::SELECT) {
           // Check that the condition doesn't reach either load.  If so, folding
@@ -5770,16 +5770,14 @@
             Load = DAG.getLoad(TheSelect->getValueType(0),
                                TheSelect->getDebugLoc(),
                                LLD->getChain(),
-                               Addr,LLD->getSrcValue(),
-                               LLD->getSrcValueOffset(),
+                               Addr, 0, 0,
                                LLD->isVolatile(),
                                LLD->getAlignment());
           } else {
             Load = DAG.getExtLoad(LLD->getExtensionType(),
                                   TheSelect->getDebugLoc(),
                                   TheSelect->getValueType(0),
-                                  LLD->getChain(), Addr, LLD->getSrcValue(),
-                                  LLD->getSrcValueOffset(),
+                                  LLD->getChain(), Addr, 0, 0,
                                   LLD->getMemoryVT(),
                                   LLD->isVolatile(),
                                   LLD->getAlignment());