Abstract: A floating point execution unit is capable of selectively repurposing a subset of the significand bits in a floating point value for use as additional exponent bits to dynamically provide an extended range for floating point calculations. A significand field of a floating point operand may be considered to include first and second portions, with the first portion capable of being concatenated with the second portion to represent the significand for a floating point value, or, to provide an extended range, being concatenated with the exponent field of the floating point operand to represent the exponent for a floating point value.

Abstract: A circuit arrangement and method support data dependent instruction decoding, whereby instructions are decoded, in part, using decode data that is stored in operand registers identified by such instructions. An instruction may include an opcode and at least one operand that identifies a register. During execution of the instruction, the instruction is first decoded using the opcode, and then decode data stored in the operand register is retrieved and used to further decode the instruction, e.g., to select from among a plurality of operations or instruction types associated with the same opcode.

Abstract: A pipelined execution unit uses the bubbles that occur during execution to selectively repeat operations performed in one or more stages of a multistage execution pipeline to verify the results of such operations during otherwise unused execution cycles for the execution pipeline. Whenever a bubble follows a particular instruction within an execution pipeline, the result of an operation that is performed for that instruction by a particular stage of the execution pipeline may be stored, and the operation may be repeated by the stage in a subsequent execution cycle in which no productive operation would otherwise be performed due to the presence of the bubble. The results of the operations may then be compared and used to either verify the original result or identify a potential error in the execution of the instruction.

Abstract: A circuit arrangement and method utilize thread pair context caching, where a pair of hardware threads in a multithreaded processor, which are each capable of executing a process, are effectively paired together, at least temporarily, to perform context switching operations such as context save and/or load operations in advance of context switches performed in one or more of such paired hardware threads. By doing so, the overall latency of a context switch, where both the context for a process being switched from must be saved, and the context for the process being switched to must be loaded, may be reduced.