Improving the computational intensity of unstructured mesh applications

Although unstructured mesh algorithms are a popular means of solving problems across a broad range of disciplines—from texture mapping to computational fluid dynamics—they are often dominated not by computation, but by mesh overhead. Our study of an object-oriented mesh-based benchmark reveals that 72% of its execution time is spent on mesh-related operations, such as iterating over faces or chasing pointers. We report a series of optimizations—some traditional, some novel—that dramatically improve the benchmark’s computational intensity—the ratio of floating point operations to memory accesses. This improvement is attributable to an eight-fold reduction in memory operations and results in a 4.7× speedup in execution time. Our work demonstrates that common subexpression elimination and code motion are important optimizations for mesh-based codes. However, conservative analysis prevents their application. We discuss these barriers to analysis and argue that an understand...

• Type: Conference
• Year: 2005
• Where: ICS
• Authors: Brian S. White, Sally A. McKee, Bronis R. de Supinski, Brian Miller, Daniel J. Quinlan, Martin Schulz
• Keywords: Execution Time, ICS 2005, Mesh-based Benchmark Reveals, Theoretical Computer Science, Unstructured Mesh Algorithms