Add some comments on ISD::NodeType.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63234 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2009-01-28 21:13:08 +00:00
parent f923574856
commit f70dab7049

View File

@ -63,6 +63,13 @@ namespace ISD {
/// ISD::NodeType enum - This enum defines all of the operators valid in a
/// SelectionDAG.
///
/// These are sometimes called the target-independent operators; targets
/// may also define target-dependent operators. For example, on x86, these
/// are the enum values in the X86ISD namespace. Targets should aim to use
/// target-independent operators to model their instruction sets as much
/// as possible, and only use target-dependent operators when they have
/// special requirements.
///
enum NodeType {
// DELETED_NODE - This is an illegal flag value that is used to catch
// errors. This opcode is not a legal opcode for any node.