Split ISD::LABEL into ISD::DBG_LABEL and ISD::EH_LABEL, eliminating

the need for a flavor operand, and add a new SDNode subclass,
LabelSDNode, for use with them to eliminate the need for a label id
operand.

Change instruction selection to let these label nodes through
unmodified instead of creating copies of them. Teach the MachineInstr
emitter how to emit a MachineInstr directly from an ISD label node.

This avoids the need for allocating SDNodes for the label id and
flavor value, as well as SDNodes for each of the post-isel label,
label id, and label flavor.

llvm-svn: 52943

1 files changed, 9 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 18810f21085..75b2c9865ec 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -523,10 +523,18 @@ unsigned MachineInstr::getNumExplicitOperands() const {
 }
 
 
+/// isLabel - Returns true if the MachineInstr represents a label.
+///
+bool MachineInstr::isLabel() const {
+  return getOpcode() == TargetInstrInfo::DBG_LABEL ||
+         getOpcode() == TargetInstrInfo::EH_LABEL ||
+         getOpcode() == TargetInstrInfo::GC_LABEL;
+}
+
 /// isDebugLabel - Returns true if the MachineInstr represents a debug label.
 ///
 bool MachineInstr::isDebugLabel() const {
-  return getOpcode() == TargetInstrInfo::LABEL && getOperand(1).getImm() == 0;
+  return getOpcode() == TargetInstrInfo::DBG_LABEL;
 }
 
 /// findRegisterUseOperandIdx() - Returns the MachineOperand that is a use of