Extended precision accumulator

In a microprocessor core having at least one general-purpose register, a method for performing arithmetic operations, the method comprising:

• fetching an instruction to perform an operation from a data store;
• reading one or more registers;
• performing the operation using a multiply unit, the multiply unit comprising:
• at least one input register for receiving one or more input operands by the multiply unit;
• a multiplier connected to receive the one or more input operands and to perform multiplication using the one or more input operands;
• and
• an extended-precision accumulated output data path connected to receive an output of the multiplier and including more bits than the sum of the lengths of the one or more input operands.

A computer-readable medium comprising a microprocessor core embodied in software, the microprocessor core including at least one general-purpose register and a multiply unit, the multiply unit comprising:

• at least one input data path for receiving one or more input operands by the multiply unit;
• a multiplier connected to receive the one or more input operands and to perform multiplication using the one or more input operands;
• and
• an extended-precision accumulated output data path connected to receive an output of the multiplier and including more bits than the sum of the lengths of the one or more input operands.

A microprocessor comprising:

• an extended-precision accumulator, wherein said accumulator includes an extended register, a high-order register and a low-order register;
• a general purpose register;
• and
• an instruction execution unit capable of facilitating a first movement of data in response to a first move instruction, said first movement of data including a moving of contents of (i) said low-order register to said general purpose register, (ii) said high-order register to said low-order register and (iii) said extended register to said high-order register.

A method for moving data comprising:

• providing an extended-precision accumulator, said accumulator including an extended register, a high-order register and a low-order register;
• providing a general purpose register;
• and
• moving data from (i) said low-order register to said general purpose register, (ii) said high-order register to said low-order register and (iii) said extended register to said high-order register in response to a first instruction.

A computer data signal embodied in a transmission medium comprising:

• computer readable first program code for providing an extended-precision accumulator, wherein said accumulator includes an extended register, a high-order register and a low-order register;
• computer readable second program code for providing a general purpose register;
• and
• computer readable third program code for providing an instruction execution unit capable of facilitating a first movement of data in response to a first move instruction, said first movement of data including a moving of contents of (i) said low-order register to said general purpose register, (ii) said high-order register to said low-order register and (iii) said extended register to said high-order register.

A method for moving data comprising:

• providing an extended-precision accumulator, the accumulator including an extended register, a high-order register and a low-order register;
• providing a general purpose register;
• and
• moving data from (i) the high-order register to the extended register, (ii) the low-order register to the high-order register and (iii) the general purpose register to the low-order register in response to a single instruction.