improved error message when rank change is not correct

Author: newling

mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp

@@ -2224,6 +2224,14 @@ LogicalResult ExpandShapeOp::verify() {
   MemRefType srcType = getSrcType();
   MemRefType resultType = getResultType();
 
+  if (srcType.getRank() > resultType.getRank()) {
+    auto r0 = srcType.getRank();
+    auto r1 = resultType.getRank();
+    return emitOpError("has source rank ")
+           << r0 << " and result rank " << r1 << ". This is not an expansion ("
+           << r0 << " > " << r1 << ").";
+  }
+
   // Verify result shape.
   if (failed(verifyCollapsedShape(getOperation(), srcType.getShape(),
                                   resultType.getShape(),
@@ -2374,6 +2382,14 @@ LogicalResult CollapseShapeOp::verify() {
   MemRefType srcType = getSrcType();
   MemRefType resultType = getResultType();
 
+  if (srcType.getRank() < resultType.getRank()) {
+    auto r0 = srcType.getRank();
+    auto r1 = resultType.getRank();
+    return emitOpError("has source rank ")
+           << r0 << " and result rank " << r1 << ". This is not a collapse ("
+           << r0 << " < " << r1 << ").";
+  }
+
   // Verify result shape.
   if (failed(verifyCollapsedShape(getOperation(), resultType.getShape(),
                                   srcType.getShape(), getReassociationIndices(),

mlir/test/Dialect/MemRef/invalid.mlir

@@ -451,7 +451,7 @@ func.func @collapse_shape_invalid_reassociation(%arg0: memref<?x?x?xf32>) {
 // An (invalid) attempt at using collapse_shape to increase the rank might look
 // like this. Verify that a sensible error is emitted in this case.
 func.func @collapse_shape_invalid_reassociation_expansion(%arg0: memref<?xf32>) {
-  // expected-error @+1 {{reassociation indices must be contiguous}}
+  // expected-error @+1 {{'memref.collapse_shape' op has source rank 1 and result rank 2. This is not a collapse (1 < 2)}}
   %0 = memref.collapse_shape %arg0 [[0], [0]] :
     memref<?xf32> into memref<?x?xf32>
 }
@@ -461,7 +461,7 @@ func.func @collapse_shape_invalid_reassociation_expansion(%arg0: memref<?xf32>)
 // An (invalid) attempt at using expand_shape to reduce the rank might look
 // like this. Verify that a sensible error is emitted in this case.
 func.func @expand_shape_invalid_reassociation(%arg0: memref<2x3x1xf32>) {
-  // expected-error @+1 {{reassociation indices must be contiguous}}
+  // expected-error @+1 {{'memref.expand_shape' op has source rank 3 and result rank 2. This is not an expansion (3 > 2)}}
   %0 = memref.expand_shape %arg0 [[0], [1], [1]] :
     memref<2x3x1xf32> into memref<2x3xf32>
 }