revert 99795, as mentioned, it is disabled anyway.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99796 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 123 deletions

diff --git a/utils/TableGen/DAGISelEmitter.cpp b/utils/TableGen/DAGISelEmitter.cpp
index 9512d430ab..f4a287c6c6 100644
--- a/utils/TableGen/DAGISelEmitter.cpp
+++ b/utils/TableGen/DAGISelEmitter.cpp
@@ -102,106 +102,6 @@ void DAGISelEmitter::EmitPredicateFunctions(raw_ostream &OS) {
   OS << "\n\n";
 }
 
-/// CouldMatchSameInput - Return true if it is possible for these two patterns
-/// to match the same input.  For example, (add reg, reg) and
-///   (add reg, (mul ...)) could both match the same input.  Where this is
-/// conservative, it falls back to returning true.
-static bool CouldMatchSameInput(const TreePatternNode *N1,
-                                const TreePatternNode *N2) {
-  // If the types of the two nodes differ, they can't match the same thing.
-  if (N1->getNumTypes() != N2->getNumTypes()) return false;
-  for (unsigned i = 0, e = N1->getNumTypes(); i != e; ++i)
-    if (N1->getType(i) != N2->getType(i))
-      return false;
-  
-  // Handle the case when at least one is a leaf.
-  if (N1->isLeaf()) {
-    if (N2->isLeaf()) {
-      // Handle leaf/leaf cases.  Register operands can match just about
-      // anything, so we can only disambiguate a few things here.
-      
-      // If both operands are leaf integer nodes with different values, they
-      // can't match the same thing.
-      if (IntInit *II1 = dynamic_cast<IntInit*>(N1->getLeafValue()))
-        if (IntInit *II2 = dynamic_cast<IntInit*>(N2->getLeafValue()))
-          return II1->getValue() == II2->getValue();
-      
-      DefInit *DI1 = dynamic_cast<DefInit*>(N1->getLeafValue());
-      DefInit *DI2 = dynamic_cast<DefInit*>(N2->getLeafValue());
-      if (DI1 != 0 && DI2 != 0) {
-        if (DI1->getDef()->isSubClassOf("ValueType") &&
-            DI2->getDef()->isSubClassOf("ValueType"))
-          return DI1 == DI2;
-        if (DI1->getDef()->isSubClassOf("CondCode") &&
-            DI2->getDef()->isSubClassOf("CondCode"))
-          return DI1 == DI2;
-      }
-
-      // TODO: Regclass cannot match a condcode etc.
-      
-      // Otherwise, complex pattern could match anything, so just return a
-      // conservative response.
-      return true;
-    }
-    
-    // Conservatively return true.  (imm) could match "7" for example, and GPR
-    // can match anything.
-    // TODO: could handle (add ...)  != "1" if we cared.
-    return true;
-  }
-  
-  // If N2 is a leaf and N1 isn't, check the other way.
-  if (N2->isLeaf())
-    return CouldMatchSameInput(N2, N1);
-  
-  // Now we know neither node is a leaf.  If the two patterns have different
-  // number of children or different operators, they can't both match.
-  Record *Op1 = N1->getOperator(), *Op2 = N1->getOperator();
-  
-  if (Op1 != Op2 || N1->getNumChildren() != N2->getNumChildren())
-    return false;
-
-  // If a child prevents the two patterns from matching, use that.
-  for (unsigned i = 0, e = N1->getNumChildren(); i != e; ++i)
-    if (!CouldMatchSameInput(N1->getChild(i), N2->getChild(i)))
-      return false;
-  
-  // Otherwise, it looks like they could both match the same thing.
-  return true;
-}
-
-/// GetSourceMatchPreferenceOrdering - The two input patterns are guaranteed to
-/// not match the same input.  Decide which pattern we'd prefer to match first
-/// in order to reduce compile time.  This sorting predicate is used to improve
-/// compile time so that we try to match scalar operations before vector
-/// operations since scalar operations are much more common in practice.
-///
-/// This returns -1 if we prefer to match N1 before N2, 1 if we prefer to match
-/// N2 before N1 or 0 if no preference.
-///
-static int GetSourceMatchPreferenceOrdering(const TreePatternNode *N1,
-                                            const TreePatternNode *N2) {
-  // The primary thing we sort on here is to get ints before floats and scalars
-  // before vectors.
-  for (unsigned i = 0, e = std::min(N1->getNumTypes(), N2->getNumTypes());
-       i != e; ++i)
-    if (N1->getType(i) != N2->getType(i)) {
-      MVT::SimpleValueType V1 = N1->getType(i), V2 = N2->getType(i);
-      if (MVT(V1).isVector() != MVT(V2).isVector())
-        return MVT(V1).isVector() ? 1 : -1;
-      
-      if (MVT(V1).isFloatingPoint() != MVT(V2).isFloatingPoint())
-        return MVT(V1).isFloatingPoint() ? 1 : -1;
-    }
-  
-  for (unsigned i = 0, e = std::min(N1->getNumChildren(), N2->getNumChildren());
-       i != e; ++i)
-    if (int Res = GetSourceMatchPreferenceOrdering(N1->getChild(i),
-                                                   N2->getChild(i)))
-      return Res;
-  return 0;
-}
-
 
 namespace {
 // PatternSortingPredicate - return true if we prefer to match LHS before RHS.
@@ -212,28 +112,6 @@ struct PatternSortingPredicate {
   CodeGenDAGPatterns &CGP;
   
   bool operator()(const PatternToMatch *LHS, const PatternToMatch *RHS) {
-    const TreePatternNode *LHSSrc = LHS->getSrcPattern();
-    const TreePatternNode *RHSSrc = RHS->getSrcPattern();
-    
-    // If the patterns are guaranteed to not match at the same time and we
-    // prefer to match one before the other (for compile time reasons) use this
-    // preference as our discriminator.
-    if (0 && !CouldMatchSameInput(LHSSrc, RHSSrc)) {
-      int Ordering = GetSourceMatchPreferenceOrdering(LHSSrc, RHSSrc);
-      if (Ordering != 0) {
-        if (Ordering == -1) {
-          errs() << "SORT: " << *LHSSrc << "\n";
-          errs() << "NEXT: " << *RHSSrc << "\n\n";
-        } else {
-          errs() << "SORT: " << *RHSSrc << "\n";
-          errs() << "NEXT: " << *LHSSrc << "\n\n";
-        }
-      }
-      
-      if (Ordering == -1) return true;
-      if (Ordering == 1) return false;
-    }
-    
     // Otherwise, if the patterns might both match, sort based on complexity,
     // which means that we prefer to match patterns that cover more nodes in the
     // input over nodes that cover fewer.
@@ -289,7 +167,8 @@ void DAGISelEmitter::run(raw_ostream &OS) {
 
   // We want to process the matches in order of minimal cost.  Sort the patterns
   // so the least cost one is at the start.
-  std::sort(Patterns.begin(), Patterns.end(), PatternSortingPredicate(CGP));
+  std::stable_sort(Patterns.begin(), Patterns.end(),
+                   PatternSortingPredicate(CGP));
   
   
   // Convert each variant of each pattern into a Matcher.