A new speculative addition architecture suitable for two's complement operations

Existing architectures for speculative addition are all based on the assumption that operands have uniformly distributed bits, which is rarely verified in real applications. As a consequence, they may be disadvantageous for real-world workloads, although in principle faster than standard adders. To address this limitation, we introduce a new architecture based on an innovative technique for speculative global carry evaluation. The proposed architecture solves the main drawback of existing schemes and, evaluated on real-world benchmarks, it exhibits an interesting performance improvement with respect to both standard adders and alternative architectures for speculative addition.