Advanced Micro Devices, Inc.
Stochastic rounding logic

Abstract:

Techniques and circuits are provided for stochastic rounding. In an embodiment, a circuit includes carry-save adder (CSA) logic having three or more CSA inputs, a CSA sum output, and a CSA carry output. One of the three or more CSA inputs is presented with a random number value, while other CSA inputs are presented with input values to be summed. The circuit further includes adder logic having adder inputs and a sum output. The CSA carry output of the CSA logic is coupled with one of the adder inputs of the adder logic, and the CSA sum output of the CSA logic is coupled with another input of the adder inputs of the adder logic. A particular number of most significant bits of the sum output of the adder logic represent a stochastically rounded sum of the input values.