US 7,257,696 B2 · Methods and apparatus for initiating and resynchronizing multi-cycle SIMD instructions

Abstract

Techniques for adding more complex instructions and their attendant multi-cycle execution units with a single instruction multiple data stream (SIMD) very long instruction word (VLIW) processing framework are described. In one aspect, an initiation mechanism also acts as a resynchronization mechanism to read the results of multi-cycle execution. This multi-purpose mechanism operates with a short instruction word (SIW) issue of the multi-cycle instruction, in a sequence processor (SP) alone, with a VLIW, and across all processing elements (PEs) individually or as an array of PEs. A number of advantageous floating point instructions are also described.

Claims27

Dependent claims

A method for initiating and resynchronizing multi-cycle instructions comprising the steps of:

executing a first multi-cycle instruction which takes more than a predetermined number of cycles to complete within a first execution module, but independently of other instructions which take less than or equal to the predetermined number of cycles to complete within a second execution module;
storing a result of the first multi-cycle instruction in a multi-cycle instruction result register at completion of its operation, and storing results of other instructions in a result register used by the other instructions but not by the first multi-cycle instruction;
and
upon receiving a second multi-cycle instruction which takes more than the predetermined number of cycles to complete, transferring the contents of the multi-cycle instruction result register to a target register specified by the second multi-cycle instruction prior to executing the second multi-cycle instruction.

1 more element

Dependencies are inferred from the claim text.

Methods and apparatus for initiating and resynchronizing multi-cycle SIMD instructions

Life of this patent

Methods and apparatus for initiating and resynchronizing multi-cycle SIMD instructions

Life of this patent

Abstract

Claims27