add an assert so that PR2356 explodes instead of running off an
array.  Improve some minor comments, refactor some helpers in
AsmOperandInfo.  No functionality change for valid code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57686 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 4e4fd2b..664e06d 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1962,6 +1962,21 @@
 //===----------------------------------------------------------------------===//
 // Constraint Selection.
 
+/// isMatchingConstraint - Return true of this is an input operand that is a
+/// matching constraint like "4".
+bool TargetLowering::AsmOperandInfo::isMatchingConstraint() const {
+  assert(!ConstraintCode.empty() && "No known constraint!");
+  return isdigit(ConstraintCode[0]);
+}
+
+/// getMatchedOperand - If this is an input matching constraint, this method
+/// returns the output operand it matches.
+unsigned TargetLowering::AsmOperandInfo::getMatchedOperand() const {
+  assert(!ConstraintCode.empty() && "No known constraint!");
+  return atoi(ConstraintCode.c_str());
+}
+
+
 /// getConstraintGenerality - Return an integer indicating how general CT
 /// is.
 static unsigned getConstraintGenerality(TargetLowering::ConstraintType CT) {