Compiler compatible 5.66 Mb/mm2 8T 1R1W register file in 14 nm FinFET technology

1-read/1-write (1R1W) register file (RF) is a popular memory configuration in modern feature rich SoCs requiring significant amount of embedded memory. A memory compiler is constructed using the 8T RF bitcell spanning a range of instances from 32 b to 72 Kb. An 8T low-leakage bitcell of 0.106 μm² is used in a 14 nm FinFET technology with a 70 nm contacted gate pitch for high-density (HD) two-port (TP) RF memory compiler which achieves 5.66 Mb/mm² array density for a 72 Kb array which is the highest reported density in 14 nm FinFET technology. The density improvement is achieved by using techniques such as leaf-cell optimization (eliminating transistors), better architectural planning, top level connectivity through leaf-cell abutment and minimizing the number of unique leaf-cells. These techniques are fully compatible with memory compiler usage over the required span. Leakage power is minimized by using power-switches without degrading the density mentioned above. Self-induced supply voltage collapse technique is applied for write and a four stack static keeper is used for read Vmin improvement. Fabricated test chips using 14 nm process have demonstrated 2.33 GHz performance at 1.1 V/25 °C operation. Overall V_min of 550 mV is achieved with this design at 25 °C. The inbuilt power-switch improves leakage power by 12x in simulation. Approximately 8% die area of a leading 14 nm SoC in commercialization is occupied by these compiled RF instances.     

基于GCC的TMS320C67xx汇编代码的优化

为了使生成的汇编代码具有更高的执行效率,设计并实现了一种基于GCC的 TMS320C67xx汇编指令级的代码优化算法。首先,将汇编指令按照功能划分为不同的指令类型,并将汇编指令链接到链表中。然后,针对每一个寄存器建立对该寄存器的读写操作指令链表。最后,通过对指令类型的判断和对寄存器读写操作指令链表的分析,完成了冗余代码的删除和指令合并。实验结果表明,经过代码优化后,TMS320C67xx汇编代码的执行效率提高了20％左右,较中间代码级的优化算法执行效率提高了15％左右。     

Syntax and semantics of universal programming languages

This paper deals with certain characterizations of the sets of positive integers which when represented as strings on a finite alphabet, form tree adjunct languages, As the context free languages constitute a subfamily of tree adjunct languages, the results carry over to the former as well.     

A self‐applicable online partial evaluator for recursive flowchart languages

This paper describes a self‐applicable online partial evaluator for a flowchart language with recursive calls. Self‐application of the partial evaluator yields generating extensions that are as efficient as those reported in the literature for offline partial evaluation. This result is remarkable because it has been assumed that online partial evaluation techniques unavoidably lead to inefficient and overgeneralized generating extensions. The purpose of this paper is not to determine which kind of partial evaluation is better, but to show how the problem can be solved by recursive polyvariant specialization. The design of the self‐applicable online partial evaluator is based on a number of known techniques, but by combining them in a new way this result can be produced. The partial evaluator, its techniques, and its implementation are presented in full. Self‐application according to all three Futamura projections is demonstrated. The complete bootstrap of a compiler generator from a partial evaluator is also reported. Copyright © 2011 John Wiley & Sons, Ltd.     

A register window scheduling method for prolog

Abstract

This paper describes a windowed register file management technique for Prolog that we call “SORWT'’ (Splittable Overlapped Register Window Technique). This scheme is implemented in our Prolog system. Two pointers, the CWP (Current Window Pointer) and TWP (Top Window Pointer), are used with the register file so that the environment, choice point and arguments can be stored in register windows. This greatly reduces the number of memory accesses and procedure call/return overhead. This paper describes in detail how Warren instructions can be implemented in a windowed register file system. A mapping function between register windows and memory window areas and register file overflow/underflow handling algorithms are also presented. In addition, to cope with argument overflow problems in a window, the concept of extended windows is proposed.

Thirty benchmark programs are used to study the following effects: performance issue of SORW versus conventional stacked register windows; optimal register file and window sizes; argument overflow rate; and the efficiency of extended windows.     

Relations among Security Models for Authenticated Key Exchange

Usually, key‐establishment protocols are suggested in a security model. However, there exist several different security models in the literature defined by their respective security notions. In this paper, we study the relations between the security models of key establishment. For the chosen security models, we first show that some proven key‐establishment protocols are not secure in the more restricted security models. We then suggest two compilers by which we can convert a key‐establishment protocol that is secure in a specific security model into a key‐establishment protocol that is still secure in a more restricted security model.     

基于建构主义的编译原理实践教学研究

建构主义教学观针对传统教学方式的弊端而提出,深受国内外教育专家的关注与重视。编译原理实践教学是理论教学的必要补充,促进学生对理论理解的同时提高了系统软件开发能力。本文在分析编译原理实践教学现状的基础上,结合建构主义现代教学观,提出了编译原理实践教学方法改革策略。     

论刘义庆与《世说新语》的编著

《世说新语》的著者,历来书目文献著录均为南朝宋临川王刘义庆,而学界目前对此存有一定争议。本文认为,尽管《世说新语》文风、选材可能不排除受刘义庆招聚的文士群体的影响,但《世说新语》能被视为“魏晋风度”的杰出范本,获得“名士教科书”的评价,仍主要是与刘义庆本人独特的家世背景、审美趣味,以及文化修养相关。     

可重构媒体处理器任务编译器的前端设计

为了解决算法程序自动映射到可重构媒体处理器的问题,有效提高程序并行执行的效率,提出一种具有自动并行化的任务编译前端. 该任务编译前端通过展开核心循环可提高并行执行度,在数据依赖分析确保运算正确执行的基础上,对循环体内的数组访问进行标量替换,以优化数据传输开销. 实验结果表明,该任务编译前端能有效提高代码并行性和优化数据传输能力,与Garp C编译器的编译前端相比,该任务编译前端设计的性能可提升约2~4倍.     

编译原理中项目集规范族的分析与研究

LR分析法是一种应用较广泛的语法分析方法,项目集规范族是构造LR分析表的基础.本文将词法分析方法与语法分析方法联系起来,以有限自动机知识为基础,给出了一种基于自动机的构造项目集规范族的方法,然后,给出了一种更简洁的方法,并比较了两种方法的异同.