摘要:
When legacy instructions, that can only operate on smaller registers, are mixed with new instructions in a processor with larger registers, special handling and architecture are used to prevent the legacy instructions from causing problems with the data in the upper portion of the registers, i.e., the portion that they cannot directly access. In some embodiments, the upper portion of the registers are saved to temporary storage while the legacy instructions are operating, and restored to the upper portion of the registers when the new instructions are operating. A special instruction may also be used to disable this save/restore operation if the new instruction are not going to use the upper part of the registers.
摘要:
A math circuit for computing an estimate of a transcendental function is described. A lookup table storage circuit has stored therein several groups of binary values, where each group of values represents a respective coefficient of a first polynomial that estimates the function to a high precision. A computing circuit uses a portion of a binary value, that is also taken from one of the groups of values, to evaluate a second polynomial that estimates the function to a low precision. Other embodiments are also described and claimed.
摘要:
A method of an aspect includes receiving a floating point scaling instruction. The floating point scaling instruction indicates a first source including one or more floating point data elements, a second source including one or more corresponding floating point data elements, and a destination. A result is stored in the destination in response to the floating point scaling instruction. The result includes one or more corresponding result floating point data elements each including a corresponding floating point data element of the second source multiplied by a base of the one or more floating point data elements of the first source raised to a power of an integer representative of the corresponding floating point data element of the first source. Other methods, apparatus, systems, and instructions are disclosed.
摘要:
Methods and apparatus relating to instructions with floating point control override are described. In an embodiment, floating point operation settings indicated by a floating point control register may be overridden on a per instruction basis. Other embodiments are also described.
摘要:
In one embodiment, the present invention includes a method for receiving a reciprocal instruction and an operand in a processor, accessing an entry of a lookup table based on a portion of the operand and the instruction, generating an encoder output based on a type of the reciprocal instruction and whether the reciprocal instruction is a legacy instruction, and selecting portions of the lookup table entry and input operand to be provided to a reciprocal logic unit based on the encoder output. Other embodiments are described and claimed.
摘要:
In-lane vector shuffle operations are described. In one embodiment a shuffle instruction specifies a field of per-lane control bits, a source operand and a destination operand, these operands having corresponding lanes, each lane divided into corresponding portions of multiple data elements. Sets of data elements are selected from corresponding portions of every lane of the source operand according to per-lane control bits. Elements of these sets are copied to specified fields in corresponding portions of every lane of the destination operand. Another embodiment of the shuffle instruction also specifies a second source operand, all operands having corresponding lanes divided into multiple data elements. A set selected according to per-lane control bits contains data elements from every lane portion of a first source operand and data elements from every corresponding lane portion of the second source operand. Set elements are copied to specified fields in every lane of the destination operand.
摘要:
A single micro-instruction to perform either an N-bit or a 2N-bit load is provided. A microprocessor having an N-bit load port performs either an N-bit load or a 2N-bit load in a single cycle with the same micro-instruction being used for both the N-bit and the 2N-bit load.
摘要:
In one embodiment, logic is provided to receive and execute a mask move instruction to transfer a vector data element including a plurality of packed data elements from a source location to a destination location, subject to mask information for the instruction. Other embodiments are described and claimed.
摘要:
Methods and apparatus relating to instructions with floating point control override are described. In an embodiment, floating point operation settings indicated by a floating point control register may be overridden on a per instruction basis. Other embodiments are also described.
摘要:
A method for conditional speed-up of execution of an instruction sequence having synchronization instructions. The method has particular application in a computer system in which compatability with instruction sequences written for the Intel 80386 or earlier processors is desirable. The method discloses replacement of certain WAIT state instruction in an instruction sequence with a null instruction in cases where the WAIT state instruction is followed by a floating point instruction including as an integral part of the instruction a WAIT state.