1. University of Michigan Electrical Engineering and Computer Science 1 Libra: Tailoring SIMD Execution using Heterogeneous Hardware and Dynamic Configurability Yongjun Park 1, Jason Jong Kyu Park 1, Hyunchul Park 2, and Scott Mahlke 1 December 3, 2012 1 University of Michigan, Ann Arbor 2 Programmin Systems Lab, Intel Labs, Santa Clara, CA

2. University of Michigan Electrical Engineering and Computer Science Mixture of ILP/DLP legacy workloads media processing web browsing scientific computing wireless communication Image processing Current mobile Solutions & Challenges 2 Good for ILPGood for DLP 1.6 GHz ARM Cortex-A9 ULP GeForce 1.7 GHz Krait Adreno 320 1.6 GHz ARM Cortex-A9 ARM Mali-400 MP4 ILP-based DLP-based Goal: Design of a flexible & energy efficient unified accelerator

3. University of Michigan Electrical Engineering and Computer Science Heterogeneous lane structure: less power/area Dynamic configurability: change ILP/DLP capability Libra: Loop-adaptive SIMD Accelerator 3 High-DLP loops Low/No-DLP loops Application ExOp-intensive loops IntExpensive unit IntExpensive unit IntExpensive unit IntExpensive unit IntExpensive unit IntExpensive unit IntExpensive unit IntExpensive unit Traditional SIMDHeterogeneous SIMD 0 1 2 3 4 5 6 7 0 1 2 3 0 1

4. University of Michigan Electrical Engineering and Computer Science Homogeneous SIMD vs. Heterogeneous Libra Control power overheads can be minimized by Functional Units power savings. 4