This book constitutes the thoroughly refereed post-proceedings of the 17th International Workshop on Languages and Compilers for High Performance Computing, LCPC 2004, held in West Lafayette, IN, USA in September 2004. The 33 revised full papers presented were carefully selected during two rounds of reviewing and improvement. The papers are organized in topical sections on compiler infrastructures; predicting and reducing memory access; locality, tiling, and partitioning; tools and techniques for parallelism and locality; Java for high-performance computing; high-level languages and optimizations; large-scale data sharing; performance studies; program analysis; and exploiting architectural features.