Dear students here we provide notes for Anna university 6TH sem Subject CS ADVANCED COMPUTER ARTCHITECTURE notes pdf. you can download. ADVANCED COMPUTER ARCHITECTURE LECTURE NOTES ANNA UNIVERSITY ADVANCED COMPUTER ARCHITECTURE LECTURE. CS ADVANCED COMPUTER ARCHITECTURE. UNIT – I. 2 Marks. is ILP .. Statically scheduled. – Dynamically scheduled (see previous lecture).
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Advanced Computer Architecture CS notes – Annauniversity lastest info
An instruction that is control dependent on a branch cannot be moved before the branch so that its execution is no longer controlled by comphter branch. Share it with your friends. If two instructions are parallel, they can execute simultaneously in a pipeline without causing any stalls. This renaming can be more easily done for register operands, where it is called register renaming.
Various types of Dependences in ILP. Static Technique — Software Dependent 2.
The importance of the data dependences is that a lectre 1 indicates the possibility of a hazard, 2 Determines the order in which results must be calculated, and 3 Sets an upper bound on how much parallelism can possibly be exploited. Add Add to Favourite Add to classroom.
The ordering between the instructions must be preserved to ensure that the value finally written corresponds to instruction j.
Since a name dependence is not a true dependence, instructions involved in advancwd name dependence can execute simultaneously nofes be reordered, if the name register number or memory location used in the instructions is changed so the instructions do not conflict. The original ordering must be preserved to ensure that i reads the correct value.
Data Dependence and Hazards: Text from page-1 Lecture Plan Subject Code: To exploit instruction-level parallelism, determine which instructions can be executed in parallel.
Touch here to read. For example, we cannot take an instruction from the then-portion of an if-statement and move it before the ifstatement. Dependences are a property of programs. CS Name of the subject: Text from page-3 Lecture Plan Subject Code: Text from page-4 Lecture Plan Subject Code: Whether a given dependence results in an actual hazard being detected and whether that hazard actually causes a stall are properties of the pipeline organization.
The second condition simply states that one instruction is dependent on another if there exists a chain of dependences of the first type between the two instructions. Both anti-dependences and output dependences are name dependences, as opposed to true data dependences, since there is no value being transmitted between the instructions. Name Notex The name dependence occurs when two instructions use the same register or memory location, called a name, arcyitecture there is no flow of data between the instructions associated with that name.
CS Advanced Computer Architecture Lecture Notes – SEC Edition
Executing the instructions simultaneously will cause architedture processor with pipeline interlocks to detect a hazard and stall, thereby reducing or eliminating the overlap. This dependence chain can be as long as the entire program.
For example, in the code segment: The various techniques that are used to increase amount of parallelism are reduces the impact of data and control hazards and increases processor ability to exploit parallelism There are two approaches to exploiting ILP.
Every instruction, except ntes those in the first basic block of the program, is control dependent on some set of branches, and, in general, these control dependences must be preserved to preserve program order. This difference is critical to understanding how instruction-level parallelism can be exploited.
An instruction j is data dependent on instruction i if either of the following holds: There are two types of name dependences between an instruction i that precedes instruction j in program order: Instruction-level parallelism ILP is the potential overlap the execution of instructions using pipeline concept to improve performance of the system.
Register renaming can be done either statically by a compiler or dynamically by the hardware.
The presence of the dependence indicates the potential for a hazard, but the actual hazard and the length of any stall is a property of the pipeline.