Multiply and accumulate circuit

A circuit arrangement comprising:

• an exponent adder circuit configured to sum a first exponent and a second exponent and generate an output exponent;
• a mantissa multiplier circuit configured to multiply a first mantissa and a second mantissa and generate an output mantissa;
• an accumulation register;
• an accumulator circuit coupled to the exponent adder circuit, mantissa multiplier, and the accumulation register, the accumulator circuit configured to sum contents of the accumulation register and a floating point number represented by the output exponent and output mantissa into an accumulated value and store the accumulated value in the accumulation register;
• first and second shared exponent registers configured for storage of a first shared exponent and a second shared exponent, respectively;
• and
• an exponent restoration circuit configured to update an exponent of the accumulated value to an expanded exponent based on the first shared exponent, second shared exponent, and the exponent of the accumulated value.

A method, comprising:

• storing a first shared exponent and a second shared exponent in first and second shared exponent registers, respectively;
• summing a first exponent and a second exponent and generating an output exponent;
• multiplying a first mantissa and a second mantissa and generating an output mantissa;
• summing contents of an accumulation register and a value based on the output exponent and output mantissa into an accumulated value;
• storing the accumulated value in the accumulation register;
• and
• updating an exponent of the accumulated value to an expanded exponent based on the first shared exponent, second shared exponent, and the exponent of the accumulated value.