[Mlir-commits] [mlir] [mlir][OpenMP] inscan reduction modifier and scan op mlir support (PR #114737)

[Sergio Afonso]

================
@@ -3125,6 +3153,34 @@ void MaskedOp::build(OpBuilder &builder, OperationState &state,
   MaskedOp::build(builder, state, clauses.filteredThreadId);
 }
 
+//===----------------------------------------------------------------------===//
+// Spec 5.2: Scan construct (5.6)
+//===----------------------------------------------------------------------===//
+
+void ScanOp::build(OpBuilder &builder, OperationState &state,
+                   const ScanOperands &clauses) {
+  ScanOp::build(builder, state, clauses.inclusiveVars, clauses.exclusiveVars);
+}
+
+LogicalResult ScanOp::verify() {
+  if (hasExclusiveVars() == hasInclusiveVars())
+    return emitError(
+        "Exactly one of EXCLUSIVE or INCLUSIVE clause is expected");
+  if (WsloopOp parentWsLoopOp = (*this)->getParentOfType<WsloopOp>())
+    if (parentWsLoopOp.getReductionModAttr() &&
+        parentWsLoopOp.getReductionModAttr().getValue() ==
+            mlir::omp::ReductionModifier::inscan)
+      return success();
+  if (SimdOp parentSimdOp = (*this)->getParentOfType<SimdOp>())
+    if (parentSimdOp.getReductionModAttr() &&
+        parentSimdOp.getReductionModAttr().getValue() ==
+            mlir::omp::ReductionModifier::inscan)
+      return success();
----------------
skatrak wrote:

Nit: Some more `mlir::omp` left behind, and braces are preferred for the outer `if` statements to avoid future "dangling else" issues while removing them for the inner statements ([link](https://llvm.org/docs/CodingStandards.html#don-t-use-braces-on-simple-single-statement-bodies-of-if-else-loop-statements)). 
```suggestion
  if (WsloopOp parentWsLoopOp = (*this)->getParentOfType<WsloopOp>()) {
    if (parentWsLoopOp.getReductionModAttr() &&
        parentWsLoopOp.getReductionModAttr().getValue() ==
            ReductionModifier::inscan)
      return success();
  }
  if (SimdOp parentSimdOp = (*this)->getParentOfType<SimdOp>()) {
    if (parentSimdOp.getReductionModAttr() &&
        parentSimdOp.getReductionModAttr().getValue() ==
            ReductionModifier::inscan)
      return success();
  }
```

https://github.com/llvm/llvm-project/pull/114737