Revert 127368 and 127371 for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127376 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 11 insertions, 24 deletions

diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
index 7b560d1..e3da208 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
@@ -570,20 +570,13 @@ void ScheduleDAGFast::ListScheduleBottomUp() {
           TRI->getMinimalPhysRegClass(Reg, VT);
         const TargetRegisterClass *DestRC = TRI->getCrossCopyRegClass(RC);
 
-        // If cross copy register class is the same as RC, then it must be
-        // possible copy the value directly. Do not try duplicate the def.
-        // If cross copy register class is not the same as RC, then it's
-        // possible to copy the value but it require cross register class copies
-        // and it is expensive.
-        // If cross copy register class is null, then it's not possible to copy
-        // the value at all.
+        // If cross copy register class is null, then it must be possible copy
+        // the value directly. Do not try duplicate the def.
         SUnit *NewDef = 0;
-        if (DestRC != RC) {
+        if (DestRC)
           NewDef = CopyAndMoveSuccessors(LRDef);
-          if (!DestRC && !NewDef)
-            report_fatal_error("Can't handle live physical "
-                               "register dependency!");
-        }
+        else
+          DestRC = RC;
         if (!NewDef) {
           // Issue copies, these can be expensive cross register class copies.
           SmallVector<SUnit*, 2> Copies;
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index 5e60aa0..f1a5a65 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -1140,19 +1140,13 @@ SUnit *ScheduleDAGRRList::PickNodeToScheduleBottomUp() {
       TRI->getMinimalPhysRegClass(Reg, VT);
     const TargetRegisterClass *DestRC = TRI->getCrossCopyRegClass(RC);
 
-    // If cross copy register class is the same as RC, then it must be possible
-    // copy the value directly. Do not try duplicate the def.
-    // If cross copy register class is not the same as RC, then it's possible to
-    // copy the value but it require cross register class copies and it is
-    // expensive.
-    // If cross copy register class is null, then it's not possible to copy
-    // the value at all.
+    // If cross copy register class is null, then it must be possible copy
+    // the value directly. Do not try duplicate the def.
     SUnit *NewDef = 0;
-    if (DestRC != RC) {
+    if (DestRC)
       NewDef = CopyAndMoveSuccessors(LRDef);
-      if (!DestRC && !NewDef)
-        report_fatal_error("Can't handle live physical register dependency!");
-    }
+    else
+      DestRC = RC;
     if (!NewDef) {
       // Issue copies, these can be expensive cross register class copies.
       SmallVector<SUnit*, 2> Copies;
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 1f464f4..fe98cac 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -337,7 +337,7 @@ X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
     else
       return &X86::GR32RegClass;
   }
-  return RC;
+  return NULL;
 }
 
 unsigned