Extend comment on ParserMatchClass .td field, and add some missing

[oota-llvm.git] / include / llvm / Target / Target.td

diff --git a/include/llvm/Target/Target.td b/include/llvm/Target/Target.td
index 98b41254fc7c0f335221bad9677f87201aca2f73..3ca7567b783e9a96d7a403f869c15e86ccd5e420 100644 (file)
--- a/include/llvm/Target/Target.td
+++ b/include/llvm/Target/Target.td
@@ -290,6 +290,11 @@ class Operand<ValueType ty> {
   // ParserMatchClass - The "match class" that operands of this type fit
   // in. Match classes are used to define the order in which instructions are
   // match, to ensure that which instructions gets matched is deterministic.
+  //
+  // The target specific parser must be able to classify an parsed operand 
+  // into a unique class, which does not partially overlap with any other 
+  // classes. It can match a subset of some other class, in which case 
+  // ParserMatchSuperClass should be set to the name of that class.
   string ParserMatchClass = "Imm";
 
   // ParserMatchSuperClass - The enclosing super class for this operand (if