Abstract: A system for adding or subtracting numbers in signed floating point notation performs exponent and mantissa handling operations in parallel. The system includes a comparator, for determining a greater-magnitude and a lesser magnitude floating point number, operating in parallel with a selector for performing a one's complement and single-bit shift on a mantissa portion of the lesser-magnitude floating point number. The system further includes a remaining shift circuit, for determining an additional amount by which the lesser-magnitude mantissa portion should be shifted; and a shifter. The system also includes an absolute add circuit, for determining whether an absolute addition or an absolute subtraction is to be performed, and a single-bit shift circuit, for indicating whether a shift of at least one bit is required.

Abstract: A write buffer having selective flush is disclosed. The write buffer has address buffers and associated data buffers and comparators. During a "sneak read" operation, the address of the read operation is compared to the address signals stored in each of the address buffers. If a match is found, the read operation is temporarily suspended for only as long as the matched address remains stored in the write buffer. In a further improvement, the overhead associated with each match can be minimized to one write operation for each match before the matched address and data signals are written out of the write buffer.