[TableGen] Introduce !listsplat 'binary' operator

Summary:
```
``!listsplat(a, size)``
    A list value that contains the value ``a`` ``size`` times.
    Example: ``!listsplat(0, 2)`` results in ``[0, 0]``.
```

I plan to use this in X86ScheduleBdVer2.td for LoadRes handling.

This is a little bit controversial because unlike every other binary operator
the types aren't identical.

Reviewers: stoklund, javed.absar, nhaehnle, craig.topper

Reviewed By: javed.absar

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60367

llvm-svn: 358117

1 files changed, 38 insertions, 0 deletions

diff --git a/llvm/lib/TableGen/TGParser.cpp b/llvm/lib/TableGen/TGParser.cpp
index f9486d4469d..937de9e5c52 100644
--- a/llvm/lib/TableGen/TGParser.cpp
+++ b/llvm/lib/TableGen/TGParser.cpp
@@ -1042,6 +1042,7 @@ Init *TGParser::ParseOperation(Record *CurRec, RecTy *ItemType) {
   case tgtok::XGe:
   case tgtok::XGt:
   case tgtok::XListConcat:
+  case tgtok::XListSplat:
   case tgtok::XStrConcat: {  // Value ::= !binop '(' Value ',' Value ')'
     tgtok::TokKind OpTok = Lex.getCode();
     SMLoc OpLoc = Lex.getLoc();
@@ -1065,6 +1066,7 @@ Init *TGParser::ParseOperation(Record *CurRec, RecTy *ItemType) {
     case tgtok::XGe:     Code = BinOpInit::GE; break;
     case tgtok::XGt:     Code = BinOpInit::GT; break;
     case tgtok::XListConcat: Code = BinOpInit::LISTCONCAT; break;
+    case tgtok::XListSplat: Code = BinOpInit::LISTSPLAT; break;
     case tgtok::XStrConcat: Code = BinOpInit::STRCONCAT; break;
     }
 
@@ -1103,6 +1105,9 @@ Init *TGParser::ParseOperation(Record *CurRec, RecTy *ItemType) {
       // We don't know the list type until we parse the first argument
       ArgType = ItemType;
       break;
+    case tgtok::XListSplat:
+      // Can't do any typechecking until we parse the first argument.
+      break;
     case tgtok::XStrConcat:
       Type = StringRecTy::get();
       ArgType = StringRecTy::get();
@@ -1142,6 +1147,33 @@ Init *TGParser::ParseOperation(Record *CurRec, RecTy *ItemType) {
             return nullptr;
           }
           break;
+        case BinOpInit::LISTSPLAT:
+          if (ItemType && InitList.size() == 1) {
+            if (!isa<ListRecTy>(ItemType)) {
+              Error(OpLoc,
+                    Twine("expected output type to be a list, got type '") +
+                        ItemType->getAsString() + "'");
+              return nullptr;
+            }
+            if (!ArgType->getListTy()->typeIsConvertibleTo(ItemType)) {
+              Error(OpLoc, Twine("expected first arg type to be '") +
+                               ArgType->getAsString() +
+                               "', got value of type '" +
+                               cast<ListRecTy>(ItemType)
+                                   ->getElementType()
+                                   ->getAsString() +
+                               "'");
+              return nullptr;
+            }
+          }
+          if (InitList.size() == 2 && !isa<IntRecTy>(ArgType)) {
+            Error(InitLoc, Twine("expected second parameter to be an int, got "
+                                 "value of type '") +
+                               ArgType->getAsString() + "'");
+            return nullptr;
+          }
+          ArgType = nullptr; // Broken invariant: types not identical.
+          break;
         case BinOpInit::EQ:
         case BinOpInit::NE:
           if (!ArgType->typeIsConvertibleTo(IntRecTy::get()) &&
@@ -1179,8 +1211,12 @@ Init *TGParser::ParseOperation(Record *CurRec, RecTy *ItemType) {
     }
     Lex.Lex();  // eat the ')'
 
+    // listconcat returns a list with type of the argument.
     if (Code == BinOpInit::LISTCONCAT)
       Type = ArgType;
+    // listsplat returns a list of type of the *first* argument.
+    if (Code == BinOpInit::LISTSPLAT)
+      Type = cast<TypedInit>(InitList.front())->getType()->getListTy();
 
     // We allow multiple operands to associative operators like !strconcat as
     // shorthand for nesting them.
@@ -1718,6 +1754,7 @@ Init *TGParser::ParseOperationCond(Record *CurRec, RecTy *ItemType) {
 ///   SimpleValue ::= SRATOK '(' Value ',' Value ')'
 ///   SimpleValue ::= SRLTOK '(' Value ',' Value ')'
 ///   SimpleValue ::= LISTCONCATTOK '(' Value ',' Value ')'
+///   SimpleValue ::= LISTSPLATTOK '(' Value ',' Value ')'
 ///   SimpleValue ::= STRCONCATTOK '(' Value ',' Value ')'
 ///   SimpleValue ::= COND '(' [Value ':' Value,]+ ')'
 ///
@@ -2031,6 +2068,7 @@ Init *TGParser::ParseSimpleValue(Record *CurRec, RecTy *ItemType,
   case tgtok::XGe:
   case tgtok::XGt:
   case tgtok::XListConcat:
+  case tgtok::XListSplat:
   case tgtok::XStrConcat:   // Value ::= !binop '(' Value ',' Value ')'
   case tgtok::XIf:
   case tgtok::XCond: