change the scope node to include a list of children to be checked
instead of to have a chained series of scope nodes. This makes
the generated table smaller, improves the efficiency of the
interpreter, and make the factoring optimization much more
reasonable to implement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97160 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/DAGISelMatcherEmitter.cpp b/utils/TableGen/DAGISelMatcherEmitter.cpp
index 93dbf2d..d2eab27 100644
--- a/utils/TableGen/DAGISelMatcherEmitter.cpp
+++ b/utils/TableGen/DAGISelMatcherEmitter.cpp
@@ -88,7 +88,7 @@
void EmitHistogram(formatted_raw_ostream &OS);
private:
- unsigned EmitMatcher(const Matcher *N, unsigned Indent,
+ unsigned EmitMatcher(const Matcher *N, unsigned Indent, unsigned CurrentIdx,
formatted_raw_ostream &OS);
unsigned getNodePredicate(StringRef PredName) {
@@ -129,6 +129,17 @@
};
} // end anonymous namespace.
+static unsigned GetVBRSize(unsigned Val) {
+ if (Val <= 127) return 1;
+
+ unsigned NumBytes = 0;
+ while (Val >= 128) {
+ Val >>= 7;
+ ++NumBytes;
+ }
+ return NumBytes+1;
+}
+
/// EmitVBRValue - Emit the specified value as a VBR, returning the number of
/// bytes emitted.
static unsigned EmitVBRValue(unsigned Val, raw_ostream &OS) {
@@ -151,11 +162,58 @@
/// EmitMatcherOpcodes - Emit bytes for the specified matcher and return
/// the number of bytes emitted.
unsigned MatcherTableEmitter::
-EmitMatcher(const Matcher *N, unsigned Indent, formatted_raw_ostream &OS) {
+EmitMatcher(const Matcher *N, unsigned Indent, unsigned CurrentIdx,
+ formatted_raw_ostream &OS) {
OS.PadToColumn(Indent*2);
switch (N->getKind()) {
- case Matcher::Scope: assert(0 && "Should be handled by caller");
+ case Matcher::Scope: {
+ const ScopeMatcher *SM = cast<ScopeMatcher>(N);
+ assert(SM->getNext() == 0 && "Shouldn't have next after scope");
+
+ unsigned StartIdx = CurrentIdx;
+
+ // Emit all of the children.
+ for (unsigned i = 0, e = SM->getNumChildren(); i != e; ++i) {
+ if (i == 0) {
+ OS << "OPC_Scope, ";
+ ++CurrentIdx;
+ } else {
+ OS << "/*" << CurrentIdx << "*/";
+ OS.PadToColumn(Indent*2) << "/*Scope*/ ";
+ }
+
+ // We need to encode the child and the offset of the failure code before
+ // emitting either of them. Handle this by buffering the output into a
+ // string while we get the size. Unfortunately, the offset of the
+ // children depends on the VBR size of the child, so for large children we
+ // have to iterate a bit.
+ SmallString<128> TmpBuf;
+ unsigned ChildSize = 0;
+ unsigned VBRSize = 0;
+ do {
+ VBRSize = GetVBRSize(ChildSize);
+
+ TmpBuf.clear();
+ raw_svector_ostream OS(TmpBuf);
+ formatted_raw_ostream FOS(OS);
+ ChildSize = EmitMatcherList(cast<ScopeMatcher>(N)->getChild(i),
+ Indent+1, CurrentIdx+VBRSize, FOS);
+ } while (GetVBRSize(ChildSize) != VBRSize);
+
+ assert(ChildSize != 0 && "Should not have a zero-sized child!");
+
+ CurrentIdx += EmitVBRValue(ChildSize, OS);
+ OS << '\n' << TmpBuf.str();
+ CurrentIdx += ChildSize;
+ }
+
+ // Emit a zero as a sentinel indicating end of 'Scope'.
+ OS << "/*" << CurrentIdx << "*/";
+ OS.PadToColumn(Indent*2) << "0, /*End of Scope*/\n";
+ return CurrentIdx - StartIdx + 1;
+ }
+
case Matcher::RecordNode:
OS << "OPC_RecordNode,";
OS.PadToColumn(CommentIndent) << "// "
@@ -387,52 +445,8 @@
Histogram.resize(N->getKind()+1);
Histogram[N->getKind()]++;
- // Scope is a special case since it is binary.
- if (const ScopeMatcher *SMN = dyn_cast<ScopeMatcher>(N)) {
- // We need to encode the child and the offset of the failure code before
- // emitting either of them. Handle this by buffering the output into a
- // string while we get the size.
- SmallString<128> TmpBuf;
- unsigned NextSize;
- {
- raw_svector_ostream OS(TmpBuf);
- formatted_raw_ostream FOS(OS);
- NextSize = EmitMatcherList(cast<ScopeMatcher>(N)->getCheck(),
- Indent+1, CurrentIdx+2, FOS);
- }
-
- // In the unlikely event that we have something too big to emit with a
- // one byte offset, regenerate it with a two-byte one.
- if (NextSize > 255) {
- TmpBuf.clear();
- raw_svector_ostream OS(TmpBuf);
- formatted_raw_ostream FOS(OS);
- NextSize = EmitMatcherList(cast<ScopeMatcher>(N)->getCheck(),
- Indent+1, CurrentIdx+3, FOS);
- if (NextSize > 65535) {
- errs() <<
- "Tblgen internal error: can't handle pattern this complex yet\n";
- exit(1);
- }
- }
-
- OS << "/*" << CurrentIdx << "*/";
- OS.PadToColumn(Indent*2);
-
- if (NextSize < 256)
- OS << "OPC_Scope, " << NextSize << ",\n";
- else
- OS << "OPC_Scope2, " << (NextSize&255) << ", " << (NextSize>>8) <<",\n";
- OS << TmpBuf.str();
-
- Size += 2+NextSize;
- CurrentIdx += 2+NextSize;
- N = SMN->getNext();
- continue;
- }
-
OS << "/*" << CurrentIdx << "*/";
- unsigned MatcherSize = EmitMatcher(N, Indent, OS);
+ unsigned MatcherSize = EmitMatcher(N, Indent, CurrentIdx, OS);
Size += MatcherSize;
CurrentIdx += MatcherSize;