Abstract: A branch ordering buffer. One disclosed apparatus includes a processor state management circuit to maintain a primary state and a shadow state, each of the primary state and the shadow state including mappings from logical registers to physical registers. The primary state is a speculative state. This disclosed apparatus also includes a branch ordering circuit to prevent the shadow state from advancing beyond a branch instruction until commitment of the branch instruction.

Abstract: Embodiments of the present invention provide a pre-decoder in a front-end system provided between an instruction cache and a decoder. The front-end system may toggle between two modes of operation. In a first mode, called the “fast mode” the front-end system retrieves pre-decoded instructions from the instruction cache and decodes them directly. In a second mode, called the “marking mode,” the front-end system retrieves data from the instruction cache and synchronizes to them prior to decoding. Synchronization results may be stored back in the instruction cache for later use.

Abstract: Self modifying code is detected using a translation lookaside buffer in order to provide cache coherency. The translation lookaside buffer has physical page addresses stored therein over which snoops can be performed using the physical memory address of a store into memory. The translation lookaside buffer includes a content addressable memory which not only provides page translation but provides content addressability based on the physical page addresses stored therein. If a match occurs during a snoop using the translation lookaside buffer, it is possible that an SMC occurred within the page of locations stored in memory associated with the matched physical page addresses. To provide finer granularity than a page of addresses, FINE HIT bits are included with each entry in the cache associating information in the cache to portions of a page within memory.

Abstract: Self modifying code is detected using a translation lookaside buffer in order to provide cache coherency. The translation lookaside buffer has physical page addresses stored therein over which snoops can be performed using the physical memory address of a store into memory. The translation lookaside buffer includes a content addressable memory which not only provides page translation but provides content addressability based on the physical page addresses stored therein. If a match occurs during a snoop using the translation lookaside buffer, it is possible that an SMC occurred within the page of locations stored in memory associated with the matched physical page addresses. To provide finer granularity than a page of addresses, FINE HIT bits are included with each entry in the cache associating information in the cache to portions of a page within memory.

Abstract: Embodiments of the present invention provide a pre-decoder in a front-end system provided between an instruction cache and a decoder. The front-end system may toggle between two modes of operation. In a first mode, called the “fast mode” the front-end system retrieves pre-decoded instructions from the instruction cache and decodes them directly. In a second mode, called the “marking mode,” the front-end system retrieves data from the instruction cache and synchronizes to them prior to decoding. Synchronization results may be stored back in the instruction cache for later use.

Abstract: Embodiments of the present invention provide a pre-decoder in a front-end system provided between an instruction cache and a decoder. The front-end system may toggle between two modes of operation. In a first mode, called the “fast mode” the front-end system retrieves pre-decoded instructions from the instruction cache and decodes them directly. In a second mode, called the “marking mode,” the front-end system retrieves data from the instruction cache and synchronizes to them prior to decoding. Synchronization results may be stored back in the instruction cache for later use.

Abstract: Embodiments of the present invention provide a pre-decoder in a front-end system provided between an instruction cache and a decoder. The front-end system may toggle between two modes of operation. In a first mode, called the “fast mode” the front-end system retrieves pre-decoded instructions from the instruction cache and decodes them directly. In a second mode, called the “marking mode,” the front-end system retrieves data from the instruction cache and synchronizes to them prior to decoding. Synchronization results may be stored back in the instruction cache for later use.