Allow direct value types in pattern definitions.

Just like register classes, value types can be used in two ways in
patterns:

  (sext_inreg i32:$src, i16)

In a named leaf node like i32:$src, the value type simply provides the
type of the node directly. This simplifies type inference a lot compared
to the current practice of specifiying types indirectly with register
classes.

As an unnamed leaf node, like i16 above, the value type represents
itself as an MVT::Other immediate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177828 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 29 insertions, 5 deletions

diff --git a/utils/TableGen/CodeGenDAGPatterns.cpp b/utils/TableGen/CodeGenDAGPatterns.cpp
index d35a2631ff..5a6960a982 100644
--- a/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -1378,9 +1378,25 @@ static EEVT::TypeSet getImplicitType(Record *R, unsigned ResNo,
     return EEVT::TypeSet();
   }
 
-  if (R->isSubClassOf("ValueType") || R->isSubClassOf("CondCode")) {
+  if (R->isSubClassOf("ValueType")) {
     assert(ResNo == 0 && "This node only has one result!");
-    // Using a VTSDNode or CondCodeSDNode.
+    // An unnamed VTSDNode represents itself as an MVT::Other immediate.
+    //
+    //   (sext_inreg GPR:$src, i16)
+    //                         ~~~
+    if (Unnamed)
+      return EEVT::TypeSet(MVT::Other, TP);
+    // With a name, the ValueType simply provides the type of the named
+    // variable.
+    //
+    //   (sext_inreg i32:$src, i16)
+    //               ~~~~~~~~
+    return EEVT::TypeSet(getValueType(R), TP);
+  }
+
+  if (R->isSubClassOf("CondCode")) {
+    assert(ResNo == 0 && "This node only has one result!");
+    // Using a CondCodeSDNode.
     return EEVT::TypeSet(MVT::Other, TP);
   }
 
diff --git a/utils/TableGen/DAGISelMatcherGen.cpp b/utils/TableGen/DAGISelMatcherGen.cpp
index 8541390b41..e91fd1e7dd 100644
--- a/utils/TableGen/DAGISelMatcherGen.cpp
+++ b/utils/TableGen/DAGISelMatcherGen.cpp
@@ -218,6 +218,17 @@ void MatcherGen::EmitLeafMatchCode(const TreePatternNode *N) {
   }
 
   Record *LeafRec = DI->getDef();
+
+  // A ValueType leaf node can represent a register when named, or itself when
+  // unnamed.
+  if (LeafRec->isSubClassOf("ValueType")) {
+    // A named ValueType leaf always matches: (add i32:$a, i32:$b).
+    if (N->hasName())
+      return;
+    // An unnamed ValueType as in (sext_inreg GPR:$foo, i8).
+    return AddMatcher(new CheckValueTypeMatcher(LeafRec->getName()));
+  }
+
   if (// Handle register references.  Nothing to do here, they always match.
       LeafRec->isSubClassOf("RegisterClass") ||
       LeafRec->isSubClassOf("RegisterOperand") ||
@@ -236,9 +247,6 @@ void MatcherGen::EmitLeafMatchCode(const TreePatternNode *N) {
     return;
   }
 
-  if (LeafRec->isSubClassOf("ValueType"))
-    return AddMatcher(new CheckValueTypeMatcher(LeafRec->getName()));
-
   if (LeafRec->isSubClassOf("CondCode"))
     return AddMatcher(new CheckCondCodeMatcher(LeafRec->getName()));