Allow register classes to match a containing class in InstAliases.
If the register class in the source alias is a subclass of the register class
of the actual instruction, the alias can still match OK since the constraints
are strictly a subset of what the instruction can actually handle.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143200 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/CodeGenInstruction.cpp b/utils/TableGen/CodeGenInstruction.cpp
index 53d499f..9822de8 100644
--- a/utils/TableGen/CodeGenInstruction.cpp
+++ b/utils/TableGen/CodeGenInstruction.cpp
@@ -423,6 +423,15 @@
return true;
}
+ // For register operands, the source register class can be a subclass
+ // of the instruction register class, not just an exact match.
+ if (ADI && ADI->getDef()->isSubClassOf("RegisterClass")) {
+ if (!InstOpRec->isSubClassOf("RegisterClass"))
+ return false;
+ return T.getRegisterClass(InstOpRec)
+ .hasSubClass(&T.getRegisterClass(ADI->getDef()));
+ }
+
// Handle explicit registers.
if (ADI && ADI->getDef()->isSubClassOf("Register")) {
if (InstOpRec->isSubClassOf("OptionalDefOperand")) {