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This article describes the Digital Continuous Profiling Infrastructure, a sampling-based profiling system designed to run continuously on production systems. The system supports multiprocessors, works on unmodified executables, and collects profiles for entire systems, including user programs, shared libraries, and the operating system kernel. Samples are(More)
hen Digital started to design the Alpha AXP architecture in the fall of 1988, the Alpha AXP team was concerned with running existing VAX TM code and MIPS TM code on the new Alpha AXP computers [5, 6]. To get full performance on a new computer architecture, an application must be ported by rebuilding, using native compilers. For a single program written in a(More)
The charter of SRC is to advance both the state of knowledge and the state of the art in computer systems. From our establishment in 1984, we have performed basic and applied research to support Digital's business objectives. Our current work includes exploring distributed personal computing on multiple platforms, networking , programming technology, system(More)
A variant of PASCAL pseudo-code which is suitable for optimization is presented. This new language, Universal pseudo-code, is designed to be easily extended to meet the needs of a variety of target machines. The language is further designed such that only one optimizer need be written for it. This approach lends itself well to the portable software spirit(More)
Trace-driven simulation is often used in the design of computer systems, especially caches and translation lookaside buffers. Capturing address traces to drive such simulations has been problematic, often involving 1000:1 software overhead to trace a target workload, and/or mechanisms that cause significant distortions in the recorded data. A new technique(More)
Thus in all these cases the Romans did what all wise princes ought to do," namely, not only to look to all present troubles, but also to those in the future, against which they provided with the utmost prudence. he Alpha AXP TM architecture grew out of a small task force chartered in 1988 to explore ways to preserve the VAX/VMS TM customer base through the(More)
The context of this paper is a machine-independent Pascal optimizer that transforms an intermediate stack-machine pseudo-code program into a generally smaller and faster pseudo-code program. The emphasis of this current paper is on the approach taken for mapping registers and storage, using an abstract but practical definition of the target machine's(More)
In an optimizing compiler, it is often desirable to compile subscript expressions such as Abase-2 + I*2 so that the value of the expression is available in a register and is simply incremented whenever I is incremented, thus avoiding the multiplication inside the loop. This change is effected by a standard optimization called strength reduction. Program(More)