LLVM Dialect: define ICmpPredicate in ODS

Use the recently introduced enum-gen functionality to define the predicate
attribute of the ICmp LLVM dialect operation directly in ODS.  This removes the
need for manually-coded string-to-integer conversion functions and contributes
to the overall homogenization of the operation definitions.

PiperOrigin-RevId: 258143923

mlir/include/mlir/LLVMIR/CMakeLists.txt

@@ -1,6 +1,8 @@
 set(LLVM_TARGET_DEFINITIONS LLVMOps.td)
 mlir_tablegen(LLVMOps.h.inc -gen-op-decls)
 mlir_tablegen(LLVMOps.cpp.inc -gen-op-defs)
+mlir_tablegen(LLVMOpsEnums.h.inc -gen-enum-decls)
+mlir_tablegen(LLVMOpsEnums.cpp.inc -gen-enum-defs)
 add_public_tablegen_target(MLIRLLVMOpsIncGen)
 set(LLVM_TARGET_DEFINITIONS NVVMOps.td)
 mlir_tablegen(NVVMOps.h.inc -gen-op-decls)

mlir/include/mlir/LLVMIR/LLVMDialect.h

@@ -34,6 +34,8 @@
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
 
+#include "mlir/LLVMIR/LLVMOpsEnums.h.inc"
+
 namespace llvm {
 class Type;
 class LLVMContext;

mlir/include/mlir/LLVMIR/LLVMOps.td

@@ -133,9 +133,28 @@ def LLVM_AndOp : LLVM_ArithmeticOp<"and", "CreateAnd">;
 def LLVM_OrOp : LLVM_ArithmeticOp<"or", "CreateOr">;
 def LLVM_XOrOp : LLVM_ArithmeticOp<"xor", "CreateXor">;
 
+def ICmpPredicateEQ  : I64EnumAttrCase<"eq", 0>;
+def ICmpPredicateNE  : I64EnumAttrCase<"ne", 1>;
+def ICmpPredicateSLT : I64EnumAttrCase<"slt", 2>;
+def ICmpPredicateSLE : I64EnumAttrCase<"sle", 3>;
+def ICmpPredicateSGT : I64EnumAttrCase<"sgt", 4>;
+def ICmpPredicateSGE : I64EnumAttrCase<"sge", 5>;
+def ICmpPredicateULT : I64EnumAttrCase<"ult", 6>;
+def ICmpPredicateULE : I64EnumAttrCase<"ule", 7>;
+def ICmpPredicateUGT : I64EnumAttrCase<"ugt", 8>;
+def ICmpPredicateUGE : I64EnumAttrCase<"uge", 9>;
+def ICmpPredicate : I64EnumAttr<
+    "ICmpPredicate",
+    "llvm.icmp comparison predicate",
+    [ICmpPredicateEQ, ICmpPredicateNE, ICmpPredicateSLT, ICmpPredicateSLE,
+     ICmpPredicateSGT, ICmpPredicateSGE, ICmpPredicateULT, ICmpPredicateULE,
+     ICmpPredicateUGT, ICmpPredicateUGE]> {
+  let cppNamespace = "mlir::LLVM";
+}
+
 // Other integer operations.
 def LLVM_ICmpOp : LLVM_OneResultOp<"icmp", [NoSideEffect]>,
-                  Arguments<(ins I64Attr:$predicate, LLVM_Type:$lhs,
+                  Arguments<(ins ICmpPredicate:$predicate, LLVM_Type:$lhs,
                              LLVM_Type:$rhs)> {
   let llvmBuilder = [{
     $res = builder.CreateICmp(getLLVMCmpPredicate(

mlir/lib/LLVMIR/IR/LLVMDialect.cpp

@@ -35,46 +35,17 @@
 using namespace mlir;
 using namespace mlir::LLVM;
 
+#include "mlir/LLVMIR/LLVMOpsEnums.cpp.inc"
+
 //===----------------------------------------------------------------------===//
 // Printing/parsing for LLVM::ICmpOp.
 //===----------------------------------------------------------------------===//
 
-// Return an array of mnemonics for ICmpPredicates indexed by its value.
-static const char *const *getICmpPredicateNames() {
-  static const char *predicateNames[]{/*EQ*/ "eq",
-                                      /*NE*/ "ne",
-                                      /*SLT*/ "slt",
-                                      /*SLE*/ "sle",
-                                      /*SGT*/ "sgt",
-                                      /*SGE*/ "sge",
-                                      /*ULT*/ "ult",
-                                      /*ULE*/ "ule",
-                                      /*UGT*/ "ugt",
-                                      /*UGE*/ "uge"};
-  return predicateNames;
-}
-
-// Returns a value of the ICmp predicate corresponding to the given mnemonic.
-// Returns -1 if there is no such mnemonic.
-static int getICmpPredicateByName(StringRef name) {
-  return llvm::StringSwitch<int>(name)
-      .Case("eq", 0)
-      .Case("ne", 1)
-      .Case("slt", 2)
-      .Case("sle", 3)
-      .Case("sgt", 4)
-      .Case("sge", 5)
-      .Case("ult", 6)
-      .Case("ule", 7)
-      .Case("ugt", 8)
-      .Case("uge", 9)
-      .Default(-1);
-}
-
 static void printICmpOp(OpAsmPrinter *p, ICmpOp &op) {
   *p << op.getOperationName() << " \""
-     << getICmpPredicateNames()[op.predicate().getZExtValue()] << "\" "
-     << *op.getOperand(0) << ", " << *op.getOperand(1);
+     << stringifyICmpPredicate(
+            static_cast<ICmpPredicate>(op.predicate().getZExtValue()))
+     << "\" " << *op.getOperand(0) << ", " << *op.getOperand(1);
   p->printOptionalAttrDict(op.getAttrs(), {"predicate"});
   *p << " : " << op.lhs()->getType();
 }
@@ -104,13 +75,15 @@ static ParseResult parseICmpOp(OpAsmParser *parser, OperationState *result) {
   if (!predicateStr)
     return parser->emitError(predicateLoc,
                              "expected 'predicate' attribute of string type");
-  int predicateValue = getICmpPredicateByName(predicateStr.getValue());
-  if (predicateValue == -1)
+  Optional<ICmpPredicate> predicateValue =
+      symbolizeICmpPredicate(predicateStr.getValue());
+  if (!predicateValue)
     return parser->emitError(predicateLoc)
            << "'" << predicateStr.getValue()
            << "' is an incorrect value of the 'predicate' attribute";
 
-  attrs[0].second = parser->getBuilder().getI64IntegerAttr(predicateValue);
+  attrs[0].second = parser->getBuilder().getI64IntegerAttr(
+      static_cast<int64_t>(predicateValue.getValue()));
 
   // The result type is either i1 or a vector type <? x i1> if the inputs are
   // vectors.