From 4f80178a104f03929e7e7ec782971830cf4cca01 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Wed, 28 Jan 2009 21:34:36 +0000 Subject: [PATCH] Add more comments describing SDNode operator codes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63239 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/SelectionDAGNodes.h | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h index 89dea1bf0f9..aec6b62650e 100644 --- a/include/llvm/CodeGen/SelectionDAGNodes.h +++ b/include/llvm/CodeGen/SelectionDAGNodes.h @@ -60,15 +60,19 @@ struct SDVTList { namespace ISD { //===--------------------------------------------------------------------===// - /// ISD::NodeType enum - This enum defines all of the operators valid in a - /// SelectionDAG. + /// ISD::NodeType enum - This enum defines the target-independent operators + /// for 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. + /// Targets may also define target-dependent operator codes for SDNodes. 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. + /// + /// Finally, during and after selection proper, SNodes may use special + /// operator codes that correspond directly with MachineInstr opcodes. These + /// are used to represent selected instructions. See the isMachineOpcode() + /// and getMachineOpcode() member functions of SDNode. /// enum NodeType { // DELETED_NODE - This is an illegal flag value that is used to catch