Tied-to constraint must be op_with_larger_idx = op_with_smaller_idx or else throw an exception.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31361 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/CodeGenTarget.cpp b/utils/TableGen/CodeGenTarget.cpp
index 489aba9..753651d 100644
--- a/utils/TableGen/CodeGenTarget.cpp
+++ b/utils/TableGen/CodeGenTarget.cpp
@@ -280,6 +280,7 @@
assert(pos != std::string::npos && "Unrecognized constraint");
std::string Name = CStr.substr(1, pos); // Skip '$'
+ // TIED_TO: $src1 = $dst
const std::string delims(" \t");
std::string::size_type wpos = Name.find_first_of(delims);
if (wpos != std::string::npos)
@@ -291,6 +292,8 @@
if (wpos != std::string::npos)
Name = Name.substr(wpos+1);
unsigned TIdx = I->getOperandNamed(Name);
+ if (TIdx >= FIdx)
+ throw "Illegal tied-to operand constraint '" + CStr + "'";
return std::make_pair(FIdx, (TIdx << 16) | 1);
}