Begin implementation of an inline spiller.

InlineSpiller inserts loads and spills immediately instead of deferring to
VirtRegMap. This is possible now because SlotIndexes allows instructions to be
inserted and renumbered.

This is work in progress, and is mostly a copy of TrivialSpiller so far. It
works very well for functions that don't require spilling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107227 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 1 deletions

diff --git a/include/llvm/CodeGen/MachineRegisterInfo.h b/include/llvm/CodeGen/MachineRegisterInfo.h
index bea64de15f..066c91b36c 100644
--- a/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -363,7 +363,18 @@ public:
     defusechain_iterator operator++(int) {        // Postincrement
       defusechain_iterator tmp = *this; ++*this; return tmp;
     }
-    
+
+    /// skipInstruction - move forward until reaching a different instruction.
+    /// Return the skipped instruction that is no longer pointed to, or NULL if
+    /// already pointing to end().
+    MachineInstr *skipInstruction() {
+      if (!Op) return 0;
+      MachineInstr *MI = Op->getParent();
+      do ++*this;
+      while (Op && Op->getParent() == MI);
+      return MI;
+    }
+
     MachineOperand &getOperand() const {
       assert(Op && "Cannot dereference end iterator!");
       return *Op;