Add a new optimization pass: Stack Coloring, that merges disjoint static allocations (allocas). Allocas are known to be

disjoint if they are marked by disjoint lifetime markers (@llvm.lifetime.XXX intrinsics).

llvm-svn: 163299

1 files changed, 9 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 1f5f8250266..754294129a8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1801,10 +1801,13 @@ WalkChainUsers(const SDNode *ChainedNode,
         User->getOpcode() == ISD::HANDLENODE)  // Root of the graph.
       continue;
 
-    if (User->getOpcode() == ISD::CopyToReg ||
-        User->getOpcode() == ISD::CopyFromReg ||
-        User->getOpcode() == ISD::INLINEASM ||
-        User->getOpcode() == ISD::EH_LABEL) {
+    unsigned UserOpcode = User->getOpcode();
+    if (UserOpcode == ISD::CopyToReg ||
+        UserOpcode == ISD::CopyFromReg ||
+        UserOpcode == ISD::INLINEASM ||
+        UserOpcode == ISD::EH_LABEL ||
+        UserOpcode == ISD::LIFETIME_START ||
+        UserOpcode == ISD::LIFETIME_END) {
       // If their node ID got reset to -1 then they've already been selected.
       // Treat them like a MachineOpcode.
       if (User->getNodeId() == -1)
@@ -2220,6 +2223,8 @@ SelectCodeCommon(SDNode *NodeToMatch, const unsigned char *MatcherTable,
   case ISD::CopyFromReg:
   case ISD::CopyToReg:
   case ISD::EH_LABEL:
+  case ISD::LIFETIME_START:
+  case ISD::LIFETIME_END:
     NodeToMatch->setNodeId(-1); // Mark selected.
     return 0;
   case ISD::AssertSext: