摘要:
An apparatus and method is described herein for providing robust speculative code section abort control mechanisms. Hardware is able to track speculative code region abort events, conditions, and/or scenarios, such as an explicit abort instruction, a data conflict, a speculative timer expiration, a disallowed instruction attribute or type, etc. And hardware, firmware, software, or a combination thereof makes an abort determination based on the tracked abort events. As an example, hardware may make an initial abort determination based on one or more predefined events or choose to pass the event information up to a firmware or software handler to make such an abort determination. Upon determining an abort of a speculative code region is to be performed, hardware, firmware, software, or a combination thereof performs the abort, which may include following a fallback path specified by hardware or software. And to enable testing of such a fallback path, in one implementation, hardware provides software a mechanism to always abort speculative code regions.
摘要:
An apparatus is described that includes an execution unit within an instruction pipeline. The execution unit has multiple stages of a circuit that includes a) and b) as follows. a) a first logic circuitry section having multiple mix logic sections each having: i) a first input to receive a first quad word and a second input to receive a second quad word; ii) an adder having a pair of inputs that are respectively coupled to the first and second inputs; iii) a rotator having a respective input coupled to the second input; iv) an XOR gate having a first input coupled to an output of the adder and a second input coupled to an output of the rotator. b) permute logic circuitry having inputs coupled to the respective adder and XOR gate outputs of the multiple mix logic sections.
摘要:
A method of an aspect includes receiving an instruction indicating a first source having at least one set of four state matrix data elements, which represent a complete set of four inputs to a G function of a cryptographic hashing algorithm. The algorithm uses a sixteen data element state matrix, and alternates between updating data elements in columns and diagonals. The instruction also indicates a second source having data elements that represent message and constant data. In response to the instruction, a result is stored in a destination indicated by the instruction. The result includes updated state matrix data elements including at least one set of four updated state matrix data elements. Each of the four updated state matrix data elements represents a corresponding one of the four state matrix data elements of the first source, which has been updated by the G function.
摘要:
A hardware-based digital random number generator is provided. In one embodiment, a processor includes a digital random number generator (DRNG) to condition entropy data provided by an entropy source, to generate a plurality of deterministic random bit (DRB) strings, and to generate a plurality of nondeterministic random bit (NRB) strings, and an execution unit coupled to the DRNG, in response to a first instruction to read a seed value, to retrieve one of the NRB strings from the DRNG and to store the NRB string in a destination register specified by the first instruction.
摘要:
A processor includes an instruction decoder to receive a first instruction to process a SHA-1 hash algorithm, the first instruction having a first operand to store a SHA-1 state, a second operand to store a plurality of messages, and a third operand to specify a hash function, and an execution unit coupled to the instruction decoder to perform a plurality of rounds of the SHA-1 hash algorithm on the SHA-1 state specified in the first operand and the plurality of messages specified in the second operand, using the hash function specified in the third operand.
摘要:
An apparatus and method is described herein for providing speculation control instructions. An xAcquire and xRelease instruction are provided to define a critical section. In one embodiment, the xAcquire instruction includes a lock instruction with an elision prefix and the xRelease instruction includes a lock release instruction with an elision prefix. As a result, a processor is able to elide locks and transactionally execute a critical section defined in software by xAcquire and xRelease. But by adding only prefix hints, legacy processor are able to execute the same code by just ignoring the hints and executing the critical section traditionally with locks to guarantee mutual exclusion. Moreover, xBegin and xEnd are similarly provided for in an Instruction Set Architecture (ISA) to define a transactional code region. In addition, other control speculation instructions, such as xAbort to enable explicit abort of a critical or transactional code section and xTest to test a state of speculative execution is also provided in the ISA.
摘要:
A processor of an aspect includes decode logic to receive a first instruction and to determine that the first instruction is to be emulated. The processor also includes emulation mode aware post-decode instruction processor logic coupled with the decode logic. The emulation mode aware post-decode instruction processor logic is to process one or more control signals decoded from an instruction. The instruction is one of a set of one or more instructions used to emulate the first instruction. The one or more control signals are to be processed differently by the emulation mode aware post-decode instruction processor logic when in an emulation mode than when not in the emulation mode. Other apparatus are also disclosed as well as methods and systems.
摘要:
An Advanced Encryption Standard (AES) key generation assist instruction is provided. The AES key generation assist instruction assists in generating round keys used to perform AES encryption and decryption operations. The AES key generation instruction operates independent of the size of the cipher key and performs key generation operations in parallel on four 32-bit words thereby increasing the speed at which the round keys are generated. This instruction is easy to use in software. Hardware implementation of this instruction removes potential threats of software (cache access based) side channel attacks on this part of the AES algorithm.
摘要:
An apparatus and method are described for processing bit streams using bit-oriented instructions. For example, a method according to one embodiment includes the operations of: executing an instruction to get bits for an operation, the instruction identifying a start bit address and a number of bits to be retrieved; retrieving the bits identified by the start bit address and number of bits from a bit-oriented register or cache; and performing a sequence of specified bit operations on the retrieved bits to generate results.
摘要:
A dynamic optimization of code for a processor-specific dynamic binary translation of hot code pages (e.g., frequently executed code pages) may be provided by a run-time translation layer. A method may be provided to use an instruction look-aside buffer (iTLB) to map original code pages and translated code pages. The method may comprise fetching an instruction from an original code page, determining whether the fetched instruction is a first instruction of a new code page and whether the original code page is deprecated. If both determinations return yes, the method may further comprise fetching a next instruction from a translated code page. If either determinations returns no, the method may further comprise decoding the instruction and fetching the next instruction from the original code page.