Correct the allocation size for CCState's UsedRegs member, which
only needs one bit for each register. UsedRegs is a SmallVector
sized at 16, so this eliminates a heap allocation/free for every
call and return processed by Legalize on most targets.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52915 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/CallingConvLower.cpp b/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
index 5dcf4ac..c9832ac 100644
--- a/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
+++ b/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
@@ -26,7 +26,7 @@
   // No stack is used.
   StackOffset = 0;
   
-  UsedRegs.resize(TRI.getNumRegs());
+  UsedRegs.resize((TRI.getNumRegs()+31)/32);
 }
 
 // HandleByVal - Allocate a stack slot large enough to pass an argument by