[mlir][affine] Verify map of affineMaxMinOp has at least one result (#108699)

This PR fixes a bug in `verifyAffineMinMaxOp` that allowed `map` of
`affine.max` and `affine.min` to have an empty result. Fixes #108368.

Author: CoTinker

mlir/lib/Dialect/Affine/IR/AffineOps.cpp

@@ -3214,6 +3214,9 @@ static LogicalResult verifyAffineMinMaxOp(T op) {
       op.getMap().getNumDims() + op.getMap().getNumSymbols())
     return op.emitOpError(
         "operand count and affine map dimension and symbol count must match");
+
+  if (op.getMap().getNumResults() == 0)
+    return op.emitOpError("affine map expect at least one result");
   return success();
 }
 

mlir/test/Dialect/Affine/invalid.mlir

@@ -178,6 +178,22 @@ func.func @affine_min(%arg0 : index, %arg1 : index, %arg2 : index) {
 
 // -----
 
+func.func @affine_min() {
+  // expected-error@+1 {{'affine.min' op affine map expect at least one result}}
+  %0 = affine.min affine_map<() -> ()> ()
+  return
+}
+
+// -----
+
+func.func @affine_min(%arg0 : index) {
+  // expected-error@+1 {{'affine.min' op affine map expect at least one result}}
+  %0 = affine.min affine_map<(d0) -> ()> (%arg0)
+  return
+}
+
+// -----
+
 func.func @affine_max(%arg0 : index, %arg1 : index, %arg2 : index) {
   // expected-error@+1 {{operand count and affine map dimension and symbol count must match}}
   %0 = affine.max affine_map<(d0) -> (d0)> (%arg0, %arg1)
@@ -205,6 +221,22 @@ func.func @affine_max(%arg0 : index, %arg1 : index, %arg2 : index) {
 
 // -----
 
+func.func @affine_max() {
+  // expected-error@+1 {{'affine.max' op affine map expect at least one result}}
+  %0 = affine.max affine_map<() -> ()> ()
+  return
+}
+
+// -----
+
+func.func @affine_max(%arg0 : index) {
+  // expected-error@+1 {{'affine.max' op affine map expect at least one result}}
+  %0 = affine.max affine_map<(d0) -> ()> (%arg0)
+  return
+}
+
+// -----
+
 func.func @affine_parallel(%arg0 : index, %arg1 : index, %arg2 : index) {
   // expected-error@+1 {{the number of region arguments (1) and the number of map groups for lower (2) and upper bound (2), and the number of steps (2) must all match}}
   affine.parallel (%i) = (0, 0) to (100, 100) step (10, 10) {