Patent ID: 6151706
Filing Date: 2000-11-21
Classification: G06F

Abstract:
A method to perform speculative code motion within a single static form partial redundancy elimination (SSAPRE) optimization, within an compiler, comprising the steps of:(1) accessing a static single assignment (SSA) representation of a computer program;(2) obtaining an SSA graph of the hypothetical variable from said SSA representation of said computer program, wherein said SSA graph comprises a plurality of connected components;(3) using a heuristic to determine a plurality of points to enable speculation within each of said plurality of connected components of said SSA graph; and(4) performing the SSAPRE optimization whereby setting a down.sub.-- safety flag to true for a .PHI. function of each of said determined plurality of points within each of said plurality of connected components of said SSA graph;whereby the compiler can produce more efficient executable program code from said SSA graph by speculating at each of said determined plurality of points where said down.sub.-- safety flag is true.