A Retargetable Instruction Reorganizer

Abstract

Extant peephole optimizers can perform many optimizations that are handled by higher - 1eve1 optimizers. This paper describes a retargetable instruction reorganizer that performs targeting and evaluation order determination by applying a well known algorithm for optimal code generation for expressions to object code. The reorganize: fits well into the framework of an existing peephole optimizer. By rearranging computations and instructions, it minimizes the number of registers and temporaries required to compile expressions. For some machines, this can reduce both the size and execution speed of programs. By generalizing its operation, the reorganizer can also be used to reorder instructions to avoid delays in pipelined machines. For one pipelined machine, it has provided a 5 to 10 percent improvement in the execution speed of benchmark programs. Note: Abstract extracted from PDF file via OCR