commit 936910d9293f7118056498c75c7bca79a7fc579c
author Craig Topper <craig.topper@gmail.com> Sat Oct 05 05:38:16 2013 +0000
committer Craig Topper <craig.topper@gmail.com> Sat Oct 05 05:38:16 2013 +0000
tree 33a480d60128c335af9b8d6d75b8936045d5bb1e
parent e8bcb9dd999d366cb6fed9f35b2d2b367289e1ec

Add OPC_CheckChildSame0-3 to the DAG isel matcher. This replaces sequences of MoveChild, CheckSame, MoveParent. Saves 846 bytes from the X86 DAG isel matcher, ~300 from ARM, ~840 from Hexagon.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192026 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 1d0ed3a..aa95f61 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -2101,6 +2101,18 @@
   return N == RecordedNodes[RecNo].first;
 }
 
+/// CheckChildSame - Implements OP_CheckChildXSame.
+LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
+CheckChildSame(const unsigned char *MatcherTable, unsigned &MatcherIndex,
+             SDValue N,
+             const SmallVectorImpl<std::pair<SDValue, SDNode*> > &RecordedNodes,
+             unsigned ChildNo) {
+  if (ChildNo >= N.getNumOperands())
+    return false;  // Match fails if out of range child #.
+  return ::CheckSame(MatcherTable, MatcherIndex, N.getOperand(ChildNo),
+                     RecordedNodes);
+}
+
 /// CheckPatternPredicate - Implements OP_CheckPatternPredicate.
 LLVM_ATTRIBUTE_ALWAYS_INLINE static bool
 CheckPatternPredicate(const unsigned char *MatcherTable, unsigned &MatcherIndex,
@@ -2215,6 +2227,13 @@
   case SelectionDAGISel::OPC_CheckSame:
     Result = !::CheckSame(Table, Index, N, RecordedNodes);
     return Index;
+  case SelectionDAGISel::OPC_CheckChild0Same:
+  case SelectionDAGISel::OPC_CheckChild1Same:
+  case SelectionDAGISel::OPC_CheckChild2Same:
+  case SelectionDAGISel::OPC_CheckChild3Same:
+    Result = !::CheckChildSame(Table, Index, N, RecordedNodes,
+                        Table[Index-1] - SelectionDAGISel::OPC_CheckChild0Same);
+    return Index;
   case SelectionDAGISel::OPC_CheckPatternPredicate:
     Result = !::CheckPatternPredicate(Table, Index, SDISel);
     return Index;
@@ -2512,6 +2531,14 @@
     case OPC_CheckSame:
       if (!::CheckSame(MatcherTable, MatcherIndex, N, RecordedNodes)) break;
       continue;
+
+    case OPC_CheckChild0Same: case OPC_CheckChild1Same:
+    case OPC_CheckChild2Same: case OPC_CheckChild3Same:
+      if (!::CheckChildSame(MatcherTable, MatcherIndex, N, RecordedNodes,
+                            Opcode-OPC_CheckChild0Same))
+        break;
+      continue;
+
     case OPC_CheckPatternPredicate:
       if (!::CheckPatternPredicate(MatcherTable, MatcherIndex, *this)) break;
       continue;