[clang] [CIR] Add if statement support (PR #134333)

[via cfe-commits]

================
@@ -447,6 +448,133 @@ mlir::LogicalResult cir::ReturnOp::verify() {
   return success();
 }
 
+//===----------------------------------------------------------------------===//
+// IfOp
+//===----------------------------------------------------------------------===//
+
+ParseResult cir::IfOp::parse(OpAsmParser &parser, OperationState &result) {
+  // create the regions for 'then'.
+  result.regions.reserve(2);
+  Region *thenRegion = result.addRegion();
+  Region *elseRegion = result.addRegion();
+
+  mlir::Builder &builder = parser.getBuilder();
+  OpAsmParser::UnresolvedOperand cond;
+  Type boolType = cir::BoolType::get(builder.getContext());
+
+  if (parser.parseOperand(cond) ||
+      parser.resolveOperand(cond, boolType, result.operands))
+    return failure();
+
+  // Parse 'then' region.
+  mlir::SMLoc parseThenLoc = parser.getCurrentLocation();
+  if (parser.parseRegion(*thenRegion, /*arguments=*/{}, /*argTypes=*/{}))
+    return failure();
+
+  if (ensureRegionTerm(parser, *thenRegion, parseThenLoc).failed())
+    return failure();
+
+  // If we find an 'else' keyword, parse the 'else' region.
+  if (!parser.parseOptionalKeyword("else")) {
+    mlir::SMLoc parseElseLoc = parser.getCurrentLocation();
+    if (parser.parseRegion(*elseRegion, /*arguments=*/{}, /*argTypes=*/{}))
+      return failure();
+    if (ensureRegionTerm(parser, *elseRegion, parseElseLoc).failed())
+      return failure();
+  }
+
+  // Parse the optional attribute list.
+  if (parser.parseOptionalAttrDict(result.attributes))
+    return failure();
+  return success();
+}
+
+void cir::IfOp::print(OpAsmPrinter &p) {
+
----------------
Andres-Salamanca wrote:

Changes applied Let me know if it looks good now

https://github.com/llvm/llvm-project/pull/134333