64-bit virtual addresses having metadata bit(s) and canonicality check that does not fail due to non-canonical values of metadata bit(s)

Techniques to allow use of metadata in unused bits of virtual addresses are described. A processor of an aspect includes a decode circuit to decode a memory access instruction. The instruction to indicate one or more memory address operands that are to have address generation information and metadata. An execution circuit coupled with the decode circuit to generate a 64-bit virtual address based on the one or more memory address operands. The 64-bit virtual address having a bit 63, an X-bit address field starting at a bit 0 to store an address generated from the address generation information, and one or more metadata bits to store the metadata. The execution circuit also to perform a canonicality check on the 64-bit virtual address that does not fail due to non-canonical values of the metadata stored in the one or more metadata bits. Other processors, methods, systems, and instructions are disclosed.