Processor and method for using an instruction hint to prevent hardware prefetch from using certain memory accesses in prefetch calculations

A method comprising:

• a prefetch unit monitoring memory accesses and determining whether to prefetch one or more blocks of memory from a system memory based upon previous memory accesses;
• calculating each next memory block to prefetch using addresses of the memory accesses;
• in response to detecting a memory access instruction including a particular hint, providing a notification;
• in response to receiving the notification, the prefetch unit discarding an address associated with the memory access instruction including the particular hint so that calculations of subsequent memory blocks to prefetch do not include the discarded address.

A computer system comprising:

• a system memory;
• a microprocessor coupled to the system memory, wherein the microprocessor includes:
• a cache memory;
• a prefetch unit coupled to the cache memory and configured to monitor memory accesses and to determine whether to prefetch one or more blocks of memory from the system memory based upon previous memory accesses, wherein the prefetch unit is further configured to use addresses of the memory accesses to calculate each next memory block to prefetch;
• detection logic configured to provide a notification in response to detecting a memory access instruction including a particular hint;
• wherein in response to receiving the notification, the prefetch unit is configured to inhibit using an address associated with the memory access instruction including the particular hint to calculate subsequent memory blocks to prefetch.