- merged_datum = raw_datum >>
- (obj_desc->common_field.access_bit_width -
- obj_desc->common_field.start_field_bit_offset);
- mask = ACPI_INTEGER_MAX;
+
+ /*
+ * Start new output datum by merging with previous input datum
+ * if necessary.
+ *
+ * Note: Before the shift, check if the shift value will be larger than
+ * the integer size. If so, there is no need to perform the operation.
+ * This avoids the differences in behavior between different compilers
+ * concerning shift values larger than the target data width.
+ */
+ if ((obj_desc->common_field.access_bit_width -
+ obj_desc->common_field.start_field_bit_offset) <
+ ACPI_INTEGER_BIT_SIZE) {
+ merged_datum =
+ raw_datum >> (obj_desc->common_field.
+ access_bit_width -
+ obj_desc->common_field.
+ start_field_bit_offset);
+ } else {
+ merged_datum = 0;
+ }
+
+ mask = width_mask;