Memory allocation method for indirect addressing with ±2{sup}n auto-modification; Access graph; Address allocation; Indirect memory addressing; DSP compiler

摘要

Indirect addressing with ±2{sup}n auto-modification is assumed, and a memory allocation method based on graph representation is proposed. Although such an indirect addressing can be easily implemented on hardware, careful allocation of program variables is required in order to reduce overhead codes. For such indirect addressing, besides its simple hardware implementation, careful allocation of program variables is required in order to avoid overhead codes. In this article, the method removes unrealizable constraints over memory allocation from a given graph representation. The proposed method in this article, first, examines memory allocation constraints, and removes constraints unrealizable by ±2{sup}n auto-modification, so that less overhead codes are required at these unrealizable constraints. Finally according to the derived overhead-free constraint graph, the method assigns a memory address to every program variables. The proposed method is applied to a DSP compiler, and its effectiveness is shown by codes generated for several examples.