convert the new matcher to check intermediate nodes for a single
use and only call IsProfitableToFold/IsLegalToFold on the load
being folded, like the old dagiselemitter does. This
substantially simplifies the code and improves opportunities for
sharing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96368 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/DAGISelHeader.h b/include/llvm/CodeGen/DAGISelHeader.h
index 7fda6f7..f4514b0 100644
--- a/include/llvm/CodeGen/DAGISelHeader.h
+++ b/include/llvm/CodeGen/DAGISelHeader.h
@@ -209,8 +209,7 @@
OPC_CheckComplexPat,
OPC_CheckAndImm1, OPC_CheckAndImm2, OPC_CheckAndImm4, OPC_CheckAndImm8,
OPC_CheckOrImm1, OPC_CheckOrImm2, OPC_CheckOrImm4, OPC_CheckOrImm8,
- OPC_IsProfitableToFold,
- OPC_IsLegalToFold
+ OPC_CheckFoldableChainNode
};
struct MatchScope {
@@ -382,19 +381,29 @@
if (CheckOrImmediate(N, GetInt8(MatcherTable, MatcherIndex))) break;
continue;
- case OPC_IsProfitableToFold:
+ case OPC_CheckFoldableChainNode: {
assert(!NodeStack.size() == 1 && "No parent node");
+ // Verify that all intermediate nodes between the root and this one have
+ // a single use.
+ bool HasMultipleUses = false;
+ for (unsigned i = 1, e = NodeStack.size()-1; i != e; ++i)
+ if (!NodeStack[i].hasOneUse()) {
+ HasMultipleUses = true;
+ break;
+ }
+ if (HasMultipleUses) break;
+
+ // Check to see that the target thinks this is profitable to fold and that
+ // we can fold it without inducing cycles in the graph.
if (!IsProfitableToFold(N, NodeStack[NodeStack.size()-2].getNode(),
- NodeToMatch))
- break;
- continue;
- case OPC_IsLegalToFold:
- assert(!NodeStack.size() == 1 && "No parent node");
- if (!IsLegalToFold(N, NodeStack[NodeStack.size()-2].getNode(),
+ NodeToMatch) ||
+ !IsLegalToFold(N, NodeStack[NodeStack.size()-2].getNode(),
NodeToMatch))
break;
+
continue;
}
+ }
// If the code reached this point, then the match failed pop out to the next
// match scope.
diff --git a/utils/TableGen/DAGISelMatcher.cpp b/utils/TableGen/DAGISelMatcher.cpp
index 3f75558..d7519ce 100644
--- a/utils/TableGen/DAGISelMatcher.cpp
+++ b/utils/TableGen/DAGISelMatcher.cpp
@@ -106,13 +106,8 @@
printChild(OS, indent);
}
-void CheckProfitableToFoldMatcherNode::print(raw_ostream &OS,
- unsigned indent) const {
- OS.indent(indent) << "CheckProfitableToFold\n";
- printChild(OS, indent);
-}
-
-void CheckLegalToFoldMatcherNode::print(raw_ostream &OS, unsigned indent) const{
- OS.indent(indent) << "CheckLegalToFold\n";
+void CheckFoldableChainNodeMatcherNode::print(raw_ostream &OS,
+ unsigned indent) const {
+ OS.indent(indent) << "CheckFoldableChainNode\n";
printChild(OS, indent);
}
diff --git a/utils/TableGen/DAGISelMatcher.h b/utils/TableGen/DAGISelMatcher.h
index b40fbf9..68737e2 100644
--- a/utils/TableGen/DAGISelMatcher.h
+++ b/utils/TableGen/DAGISelMatcher.h
@@ -50,8 +50,7 @@
CheckComplexPat,
CheckAndImm,
CheckOrImm,
- CheckProfitableToFold,
- CheckLegalToFold
+ CheckFoldableChainNode
};
const KindTy Kind;
@@ -359,33 +358,20 @@
virtual void print(raw_ostream &OS, unsigned indent = 0) const;
};
-/// CheckProfitableToFoldMatcherNode - This checks to see if the current node is
-/// worthwhile to try to fold into a large pattern.
-class CheckProfitableToFoldMatcherNode : public MatcherNodeWithChild {
+/// CheckFoldableChainNodeMatcherNode - This checks to see if the current node
+/// (which defines a chain operand) is safe to fold into a larger pattern.
+class CheckFoldableChainNodeMatcherNode : public MatcherNodeWithChild {
public:
- CheckProfitableToFoldMatcherNode()
- : MatcherNodeWithChild(CheckProfitableToFold) {}
+ CheckFoldableChainNodeMatcherNode()
+ : MatcherNodeWithChild(CheckFoldableChainNode) {}
static inline bool classof(const MatcherNode *N) {
- return N->getKind() == CheckProfitableToFold;
+ return N->getKind() == CheckFoldableChainNode;
}
virtual void print(raw_ostream &OS, unsigned indent = 0) const;
};
-/// CheckLegalToFoldMatcherNode - This checks to see if the current node is
-/// legal to try to fold into a large pattern.
-class CheckLegalToFoldMatcherNode : public MatcherNodeWithChild {
-public:
- CheckLegalToFoldMatcherNode()
- : MatcherNodeWithChild(CheckLegalToFold) {}
-
- static inline bool classof(const MatcherNode *N) {
- return N->getKind() == CheckLegalToFold;
- }
-
- virtual void print(raw_ostream &OS, unsigned indent = 0) const;
-};
} // end namespace llvm
#endif
diff --git a/utils/TableGen/DAGISelMatcherEmitter.cpp b/utils/TableGen/DAGISelMatcherEmitter.cpp
index c0ad169..c414918 100644
--- a/utils/TableGen/DAGISelMatcherEmitter.cpp
+++ b/utils/TableGen/DAGISelMatcherEmitter.cpp
@@ -183,11 +183,8 @@
OS << "OPC_CheckOrImm" << ClassifyInt(Val) << ", ";
return EmitInt(Val, OS)+1;
}
- case MatcherNode::CheckProfitableToFold:
- OS << "OPC_IsProfitableToFold,\n";
- return 1;
- case MatcherNode::CheckLegalToFold:
- OS << "OPC_IsLegalToFold,\n";
+ case MatcherNode::CheckFoldableChainNode:
+ OS << "OPC_CheckFoldableChainNode,\n";
return 1;
}
assert(0 && "Unreachable");
diff --git a/utils/TableGen/DAGISelMatcherGen.cpp b/utils/TableGen/DAGISelMatcherGen.cpp
index 07ab472..fac5824 100644
--- a/utils/TableGen/DAGISelMatcherGen.cpp
+++ b/utils/TableGen/DAGISelMatcherGen.cpp
@@ -212,9 +212,7 @@
const TreePatternNode *Root = Pattern.getSrcPattern();
if (N != Root && // Not the root of the pattern.
N->TreeHasProperty(SDNPHasChain, CGP)) { // Has a chain somewhere in tree.
-
- AddMatcherNode(new CheckProfitableToFoldMatcherNode());
-
+
// If this non-root node produces a chain, we may need to emit a validity
// check.
if (OpNo != 0) {
@@ -239,7 +237,7 @@
}
if (NeedCheck)
- AddMatcherNode(new CheckLegalToFoldMatcherNode());
+ AddMatcherNode(new CheckFoldableChainNodeMatcherNode());
}
}