If a node that defines a physical register that is expensive to copy. The

scheduler will try a number of tricks in order to avoid generating the
copies. This may not be possible in case the node produces a chain value
that prevent movement. Try unfolding the load from the node before to allow
it to be moved / cloned.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42625 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/ScheduleDAG.h

@@ -115,7 +115,7 @@ namespace llvm {
     short NumSuccsLeft;                 // # of succs not scheduled.
     bool isTwoAddress     : 1;          // Is a two-address instruction.
     bool isCommutable     : 1;          // Is a commutable instruction.
-    bool hasPhysRegDefs  : 1;           // Has physreg defs that are being used.
+    bool hasPhysRegDefs   : 1;          // Has physreg defs that are being used.
     bool isPending        : 1;          // True once pending.
     bool isAvailable      : 1;          // True once available.
     bool isScheduled      : 1;          // True once scheduled.
@@ -297,6 +297,10 @@ namespace llvm {
     /// together nodes with a single SUnit.
     void BuildSchedUnits();
 
+    /// ComputeLatency - Compute node latency.
+    ///
+    void ComputeLatency(SUnit *SU);
+
     /// CalculateDepths, CalculateHeights - Calculate node depth / height.
     ///
     void CalculateDepths();