[mlir][drr] Fix getValueAndRangeUse for Optional operands (#138742)

Optional operands should just return one single value.

mlir/lib/TableGen/Pattern.cpp

diff --git a/mlir/lib/TableGen/Pattern.cpp b/mlir/lib/TableGen/Pattern.cpp
index d83df3e..ab60539 100644
--- a/mlir/lib/TableGen/Pattern.cpp
+++ b/mlir/lib/TableGen/Pattern.cpp
@@ -303,6 +303,12 @@
   case Kind::Operand: {
     assert(index < 0);
     auto *operand = cast<NamedTypeConstraint *>(op->getArg(getArgIndex()));
+    if (operand->isOptional()) {
+      auto repl =
+          formatv(fmt, formatv("({0}.empty() ? Value() : *{0}.begin())", name));
+      LLVM_DEBUG(dbgs() << repl << " (OptionalOperand)\n");
+      return std::string(repl);
+    }
     // If this operand is variadic and this SymbolInfo doesn't have a range
     // index, then return the full variadic operand_range. Otherwise, return
     // the value itself.

mlir/test/lib/Dialect/Test/TestOps.td

diff --git a/mlir/test/lib/Dialect/Test/TestOps.td b/mlir/test/lib/Dialect/Test/TestOps.td
index 85a49e0..3e46199 100644
--- a/mlir/test/lib/Dialect/Test/TestOps.td
+++ b/mlir/test/lib/Dialect/Test/TestOps.td
@@ -1850,6 +1850,20 @@
   (MixedVOperandOp5 $input2a, $input2b, $input1b, $attr1,
                     ConstantStrAttr<StrAttr, "MatchMultiVariadicSubSymbol">)>;
 
+def MixedVOperandOp7 : TEST_Op<"mixed_variadic_optional_in7",
+                               [AttrSizedOperandSegments]> {
+  let arguments = (ins
+    Variadic<I32>:$input1,
+    Optional<I32>:$input2,
+    I32Attr:$attr1
+  );
+}
+
+def : Pat<
+  (MixedVOperandOp7 $input1, $input2, ConstantAttr<I32Attr, "2">:$attr1),
+  (MixedVOperandOp6 $input1, (variadic $input2), $attr1),
+  [(Constraint<CPred<"$0 != Value()">> $input2)]>;
+
 //===----------------------------------------------------------------------===//
 // Test Patterns (either)
 //===----------------------------------------------------------------------===//

mlir/test/mlir-tblgen/pattern.mlir

diff --git a/mlir/test/mlir-tblgen/pattern.mlir b/mlir/test/mlir-tblgen/pattern.mlir
index 60d46e6..9090528 100644
--- a/mlir/test/mlir-tblgen/pattern.mlir
+++ b/mlir/test/mlir-tblgen/pattern.mlir
@@ -584,6 +584,16 @@
   return
 }
 
+// CHECK-LABEL: @testMatchMixedVaradicOptional
+func.func @testMatchMixedVaradicOptional(%arg0: i32, %arg1: i32, %arg2: i32, %arg3: i32) -> () {
+  // CHECK: "test.mixed_variadic_in6"(%arg0, %arg1, %arg2) <{attr1 = 2 : i32}> : (i32, i32, i32) -> () 
+  "test.mixed_variadic_optional_in7"(%arg0, %arg1, %arg2) {attr1 = 2 : i32, operandSegmentSizes = array<i32: 2, 1>} : (i32, i32, i32) -> ()
+  // CHECK: test.mixed_variadic_optional_in7
+  "test.mixed_variadic_optional_in7"(%arg0, %arg1) {attr1 = 2 : i32, operandSegmentSizes = array<i32: 2, 0>} : (i32, i32) -> ()
+
+  return
+}
+
 //===----------------------------------------------------------------------===//
 // Test that natives calls are only called once during rewrites.
 //===----------------------------------------------------------------------===//