add an optimized form of OPC_EmitMergeInputChains for the 1, 0 and
1, 1 cases which are by-far the most frequent. This shrinks the X86
isel table from 77014 -> 74657 bytes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99740 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 3981826..6e5a6ad 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -2440,6 +2440,35 @@
continue;
}
+ case OPC_EmitMergeInputChains1_0: // OPC_EmitMergeInputChains, 1, 0
+ case OPC_EmitMergeInputChains1_1: { // OPC_EmitMergeInputChains, 1, 1
+ // These are space-optimized forms of OPC_EmitMergeInputChains.
+ assert(InputChain.getNode() == 0 &&
+ "EmitMergeInputChains should be the first chain producing node");
+ assert(ChainNodesMatched.empty() &&
+ "Should only have one EmitMergeInputChains per match");
+
+ // Read all of the chained nodes.
+ unsigned RecNo = Opcode == OPC_EmitMergeInputChains1_1;
+ assert(RecNo < RecordedNodes.size() && "Invalid CheckSame");
+ ChainNodesMatched.push_back(RecordedNodes[RecNo].getNode());
+
+ // FIXME: What if other value results of the node have uses not matched
+ // by this pattern?
+ if (ChainNodesMatched.back() != NodeToMatch &&
+ !RecordedNodes[RecNo].hasOneUse()) {
+ ChainNodesMatched.clear();
+ break;
+ }
+
+ // Merge the input chains if they are not intra-pattern references.
+ InputChain = HandleMergeInputChains(ChainNodesMatched, CurDAG);
+
+ if (InputChain.getNode() == 0)
+ break; // Failed to merge.
+ continue;
+ }
+
case OPC_EmitMergeInputChains: {
assert(InputChain.getNode() == 0 &&
"EmitMergeInputChains should be the first chain producing node");