Profile-assisted Compiler Support for Dynamic Predication in Diverge-Merge Processors

Dynamic predication has been proposed to reduce the branch misprediction penalty due to hard-to-predict branch instructions. A recently proposed dynamic predication architecture, the diverge-merge processor (DMP), provides large performance improvements by dynamically predicating a large set of complex control-flow graphs that result in branch mispredictions. DMP requires significant support from a profiling compiler to determine which branch instructions and control-flow structures can be dynamically predicated. However, previous work on dynamic predication did not extensively examine the tradeoffs involved in profiling and code generation for dynamic predication architectures. This paper describes compiler support for obtaining high performance in the diverge-merge processor. We describe new profile-driven algorithms and heuristics to select branch instructions that are suitable and profitable for dynamic predication. We also develop a new profile-based analytical cost-benefit model...

• Type: Conference
• Year: 2007
• Where: CGO
• Authors: Hyesoon Kim, José A. Joao, Onur Mutlu, Yale N. Patt
• Keywords: Branch Instructions, CGO 2007, Dynamic Predication, Dynamic Predication Architectures, Software Engineering