Revert r161633-161634 "Partition use lists so defs always come before uses."

These commits broke a number of buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161640 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 10 insertions, 15 deletions

diff --git a/include/llvm/CodeGen/MachineOperand.h b/include/llvm/CodeGen/MachineOperand.h
index adf20956a8..0cde75d1df 100644
--- a/include/llvm/CodeGen/MachineOperand.h
+++ b/include/llvm/CodeGen/MachineOperand.h
@@ -150,7 +150,7 @@ private:
 
     struct {                  // For MO_Register.
       // Register number is in SmallContents.RegNo.
-      MachineOperand *Prev;   // Access list for register. See MRI.
+      MachineOperand **Prev;  // Access list for register.
       MachineOperand *Next;
     } Reg;
 
diff --git a/include/llvm/CodeGen/MachineRegisterInfo.h b/include/llvm/CodeGen/MachineRegisterInfo.h
index 42a8aa43d9..0fac1a85bb 100644
--- a/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -468,6 +468,10 @@ public:
                         const TargetRegisterInfo &TRI,
                         const TargetInstrInfo &TII);
 
+private:
+  void HandleVRegListReallocation();
+
+public:
   /// defusechain_iterator - This class provides iterator support for machine
   /// operands in the function that use or define a specific register.  If
   /// ReturnUses is true it returns uses of registers, if ReturnDefs is true it
@@ -513,20 +517,11 @@ public:
       assert(Op && "Cannot increment end iterator!");
       Op = getNextOperandForReg(Op);
 
-      // All defs come before the uses, so stop def_iterator early.
-      if (!ReturnUses) {
-        if (Op) {
-          if (Op->isUse())
-            Op = 0;
-          else
-            assert(!Op->isDebug() && "Can't have debug defs");
-        }
-      } else {
-        // If this is an operand we don't care about, skip it.
-        while (Op && ((!ReturnDefs && Op->isDef()) ||
-                      (SkipDebug && Op->isDebug())))
-          Op = getNextOperandForReg(Op);
-      }
+      // If this is an operand we don't care about, skip it.
+      while (Op && ((!ReturnUses && Op->isUse()) ||
+                    (!ReturnDefs && Op->isDef()) ||
+                    (SkipDebug && Op->isDebug())))
+        Op = getNextOperandForReg(Op);
 
       return *this;
     }