Add @earlyclobber TableGen constraint

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91554 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 12b974d..e3b8709 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -555,8 +555,13 @@
       Operands.back().ParentMI = this;
   
       // If the operand is a register, update the operand's use list.
-      if (Op.isReg())
+      if (Op.isReg()) {
         Operands.back().AddRegOperandToRegInfo(RegInfo);
+        // If the register operand is flagged as early, mark the operand as such
+        unsigned OpNo = Operands.size() - 1;
+        if (TID->getOperandConstraint(OpNo, TOI::EARLY_CLOBBER) != -1)
+          Operands[OpNo].setIsEarlyClobber(true);
+      }
       return;
     }
   }
@@ -573,8 +578,12 @@
 
     // Do explicitly set the reginfo for this operand though, to ensure the
     // next/prev fields are properly nulled out.
-    if (Operands[OpNo].isReg())
+    if (Operands[OpNo].isReg()) {
       Operands[OpNo].AddRegOperandToRegInfo(0);
+      // If the register operand is flagged as early, mark the operand as such
+      if (TID->getOperandConstraint(OpNo, TOI::EARLY_CLOBBER) != -1)
+        Operands[OpNo].setIsEarlyClobber(true);
+    }
 
   } else if (Operands.size()+1 <= Operands.capacity()) {
     // Otherwise, we have to remove register operands from their register use
@@ -594,8 +603,12 @@
     Operands.insert(Operands.begin()+OpNo, Op);
     Operands[OpNo].ParentMI = this;
 
-    if (Operands[OpNo].isReg())
+    if (Operands[OpNo].isReg()) {
       Operands[OpNo].AddRegOperandToRegInfo(RegInfo);
+      // If the register operand is flagged as early, mark the operand as such
+      if (TID->getOperandConstraint(OpNo, TOI::EARLY_CLOBBER) != -1)
+        Operands[OpNo].setIsEarlyClobber(true);
+    }
     
     // Re-add all the implicit ops.
     for (unsigned i = OpNo+1, e = Operands.size(); i != e; ++i) {
@@ -613,6 +626,11 @@
   
     // Re-add all the operands.
     AddRegOperandsToUseLists(*RegInfo);
+
+      // If the register operand is flagged as early, mark the operand as such
+    if (Operands[OpNo].isReg()
+        && TID->getOperandConstraint(OpNo, TOI::EARLY_CLOBBER) != -1)
+      Operands[OpNo].setIsEarlyClobber(true);
   }
 }