  Abstract interpretation is a general framework for expressing static program
analyses. It reduces the problem of extracting properties of a program to
computing an approximation of the least fixpoint of a system of equations. The
de facto approach for computing this approximation uses a sequential algorithm
based on weak topological order (WTO). This paper presents a deterministic
parallel algorithm for fixpoint computation by introducing the notion of weak
partial order (WPO). We present an algorithm for constructing a WPO in
almost-linear time. Finally, we describe PIKOS, our deterministic parallel
abstract interpreter, which extends the sequential abstract interpreter IKOS.
We evaluate the performance and scalability of PIKOS on a suite of 1017 C
programs. When using 4 cores, PIKOS achieves an average speedup of 2.06x over
IKOS, with a maximum speedup of 3.63x. When using 16 cores, PIKOS achieves a
maximum speedup of 10.97x.
