Recovery of array type on incomplete variable subscript 非纯变量下标的数组类型恢复
Some of the safe mobile codes may be rejected to execute, since there is no way to verify statically that the symbol range value of an array subscript expression in PCC. PCC的数组边界检查存在着由于无法确定数组下标表达式符号值的范围,而造成拒绝执行一些安全的移动代码等问题。
After thoroughly analyzing the GCC 4.1 data dependence analyzer, we make two contributions to overcome its limitations on analyzing linearized array references of Fortran programs. First, we implement a preliminary data dependence analysis algorithm for nonaffine array subscript references. 本文深入分析了GCC4·1的数据依赖分析器,针对它在分析Fortran程序的线性化数组访问时的不足,给出了两点改进:一是初步实现了一个非仿射数组下标依赖分析算法;
Second, we present and implement a data dependence analysis method for affine array subscript references by splitting the chain of recurrences. 二是提出并实现了分裂递归链的仿射数组下标数据依赖分析方法。
The original analysis of data dependence between loops in GCC is weak for non-line array and more subscript indexes. GCC中原有的数据依赖性分析机制对于非线性数组分析能力较弱,对于多索引下标数组的分析也存在很大的不足。
Among thses matrices, bidiagonal matrix and approximately lower triangular array matrix have determinate construction and can provide linear encoding algorithm, and both subscript matrices, masking matrix and permutation matrix need to be redesigned. 其中双对角线矩阵和近似下三角阵列矩阵是确定结构的,具有高速线性编码的功能;而两种下标矩阵、模板矩阵和置换矩阵均具有类随机结构特征,可以根据需要进行再设计。