Mips Technologies, Inc.

Chinh Nguyen Tran

Radhika Thekkath

Ryan C Kinter

Darren Miller Jones

The present invention provides processing systems, apparatuses, and methods that support both general processing processor (GPP) and digital signal processor (DSP) features, such as vector and single value multiplication. In an embodiment, fractional arithmetic, integer arithmetic, saturation, and single instruction multiple data (SIMD) operations such as vector multiply, multiply accumulate, dot-product accumulate, and multiply-subtract accumulate are supported. In an embodiment, the process core and/or multiplier multiplies vector values or single values by creating partial products for each desired product. These partial products are added to produce intermediate results, which are combined in different ways to support various GPP and DSP operations.

Processor core and multiplier that support both vector and single value multiplication

Processor core and multiplier that support a multiply and difference operation by inverting sign bits in booth recoding

A modular subtraction instruction for execution on a microprocessor having at least one register. The instruction includes opcode bits for designating the instruction and operand bits for designating at least one register storing an offset index, a decrement value, and an address index. When the modular subtraction instruction is executed on the microprocessor, the address index is modified by the decrement value if the address index is not zero and is modified by the offset index if the address index is zero. For example, the address index is repeatedly decremented using the decrement value until it reaches zero, and then the address index is reset back to the offset index. The operand bits may include multiple fields identifying multiple registers selected from the general purpose registers of the microprocessor. The modular subtraction instruction enables access to a buffer in memory in circular fashion by virtue of its operation.

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Palo Alto, CA, United States of America

Chinh Nguyen Tran