[Mlir-commits] [mlir] Add a structured if operation (PR #67234)

[Gil Rapaport]

================
@@ -567,28 +580,19 @@ static LogicalResult printOperation(CppEmitter &emitter, scf::ForOp forOp) {
   return success();
 }
 
-static LogicalResult printOperation(CppEmitter &emitter, scf::IfOp ifOp) {
+static LogicalResult printOperation(CppEmitter &emitter, emitc::IfOp ifOp) {
   raw_indented_ostream &os = emitter.ostream();
 
-  if (!emitter.shouldDeclareVariablesAtTop()) {
-    for (OpResult result : ifOp.getResults()) {
-      if (failed(emitter.emitVariableDeclaration(result,
-                                                 /*trailingSemicolon=*/true)))
-        return failure();
-    }
-  }
-
   os << "if (";
   if (failed(emitter.emitOperands(*ifOp.getOperation())))
     return failure();
   os << ") {\n";
   os.indent();
 
   Region &thenRegion = ifOp.getThenRegion();
-  for (Operation &op : thenRegion.getOps()) {
-    // Note: This prints a superfluous semicolon if the terminating yield op has
-    // zero results.
-    if (failed(emitter.emitOperation(op, /*trailingSemicolon=*/true)))
+  auto thenOps = thenRegion.getOps();
+  for (auto it = thenOps.begin(); std::next(it) != thenOps.end(); ++it) {
+    if (failed(emitter.emitOperation(*it, /*trailingSemicolon=*/true)))
----------------
aniragil wrote:

Yes, as in emitc::yield's case it's always superfluous. I actually took this code from scf::for's printOperation() without adding a similar comment. Will add a comment to clarify and outline into a lambda to be used for both 'then' and 'else' regions.

https://github.com/llvm/llvm-project/pull/67234