add a new OPC_SwitchOpcode which is semantically equivalent
to a scope where every child starts with a CheckOpcode, but
executes more efficiently. Enhance DAGISelMatcherOpt to
form it.
This also fixes a bug in CheckOpcode: apparently the SDNodeInfo
objects are not pointer comparable, we have to compare the
enum name.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97438 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/DAGISelMatcherOpt.cpp b/utils/TableGen/DAGISelMatcherOpt.cpp
index 5fe21f6..41ce6ae 100644
--- a/utils/TableGen/DAGISelMatcherOpt.cpp
+++ b/utils/TableGen/DAGISelMatcherOpt.cpp
@@ -15,6 +15,7 @@
#include "DAGISelMatcher.h"
#include "CodeGenDAGPatterns.h"
#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringSet.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <vector>
@@ -152,7 +153,8 @@
// like X86 where many operations are valid on multiple types.
if ((isa<CheckTypeMatcher>(N) || isa<CheckChildTypeMatcher>(N) ||
isa<RecordMatcher>(N)) &&
- isa<CheckOpcodeMatcher>(N->getNext())) {
+ (isa<CheckOpcodeMatcher>(N->getNext()) ||
+ isa<CheckMultiOpcodeMatcher>(N->getNext()))) {
// Unlink the two nodes from the list.
Matcher *CheckType = MatcherPtr.take();
Matcher *CheckOpcode = CheckType->takeNext();
@@ -256,7 +258,7 @@
}
SmallVector<Matcher*, 32> NewOptionsToMatch;
-
+
// Loop over options to match, merging neighboring patterns with identical
// starting nodes into a shared matcher.
for (unsigned OptionIdx = 0, e = OptionsToMatch.size(); OptionIdx != e;) {
@@ -342,13 +344,55 @@
NewOptionsToMatch.push_back(Shared);
}
+
+ // If we're down to a single pattern to match, then we don't need this scope
+ // anymore.
+ if (NewOptionsToMatch.size() == 1) {
+ MatcherPtr.reset(NewOptionsToMatch[0]);
+ return;
+ }
+
+ // If our factoring failed (didn't achieve anything) see if we can simplify in
+ // other ways.
+
+ // Check to see if all of the leading entries are now opcode checks. If so,
+ // we can convert this Scope to be a OpcodeSwitch instead.
+ bool AllOpcodeChecks = true;
+ for (unsigned i = 0, e = NewOptionsToMatch.size(); i != e; ++i) {
+ if (isa<CheckOpcodeMatcher>(NewOptionsToMatch[i])) continue;
+
+#if 0
+ if (i > 3) {
+ errs() << "FAILING OPC #" << i << "\n";
+ NewOptionsToMatch[i]->dump();
+ }
+#endif
+
+ AllOpcodeChecks = false;
+ break;
+ }
+
+ // If all the options are CheckOpcode's, we can form the SwitchOpcode, woot.
+ if (AllOpcodeChecks) {
+ StringSet<> Opcodes;
+ SmallVector<std::pair<const SDNodeInfo*, Matcher*>, 8> Cases;
+ for (unsigned i = 0, e = NewOptionsToMatch.size(); i != e; ++i) {
+ CheckOpcodeMatcher *COM =cast<CheckOpcodeMatcher>(NewOptionsToMatch[i]);
+ assert(Opcodes.insert(COM->getOpcode().getEnumName()) &&
+ "Duplicate opcodes not factored?");
+ Cases.push_back(std::make_pair(&COM->getOpcode(), COM->getNext()));
+ }
+
+ MatcherPtr.reset(new SwitchOpcodeMatcher(&Cases[0], Cases.size()));
+ return;
+ }
+
// Reassemble a new Scope node.
- assert(!NewOptionsToMatch.empty() && "where'd all our children go?");
+ assert(!NewOptionsToMatch.empty() &&
+ "Where'd all our children go? Did we really factor everything??");
if (NewOptionsToMatch.empty())
MatcherPtr.reset(0);
- if (NewOptionsToMatch.size() == 1)
- MatcherPtr.reset(NewOptionsToMatch[0]);
else {
Scope->setNumChildren(NewOptionsToMatch.size());
for (unsigned i = 0, e = NewOptionsToMatch.size(); i != e; ++i)