10-1 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Computer Architecture and Organization Miles Murdocca and Vincent Heuring Chapter 10 – Advanced Computer Architecture

10-2 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Chapter Contents 10.1 Parallel Architecture 10.2 Superscalar Machines and the PowerPC 10.3 VLIW Machines, and the Itanium 10.4 Case Study: Extensions to the Instruction Set – The Intel MMX/SSEX and Motorola Altivec SIMD Instructions 10.5 Programmable Logic Devices and Custom ICs 10.6 Unconventional Architectures

10-3 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Parallel Speedup and Amdahl’s Law In the context of parallel processing, speedup can be computed: Amdahl’s law, for p processors and a fraction f of unparallelizable code: For example, if f = 10% of the operations must be performed sequentially, then speedup can be no greater than 10 regardless of how many processors are used:

10-4 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Efficiency and Throughput Efficiency is the ratio of speedup to the number of processors used. For a speedup of 5.3 with 10 processors, the efficiency is: Throughput is a measure of how much computation is achieved over time, and is of special concern for I/O bound and pipelined applications. For the case of a four stage pipeline that remains filled, in which each pipeline stage completes its task in 10 ns, the average time to complete an operation is 10 ns even though it takes 40 ns to execute any one operation. The overall throughput for this situation is then:

10-5 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Flynn Taxonomy Classification of architectures according to the Flynn taxonomy: (a) SISD; (b) SIMD; (c) MIMD; (d) MISD.

10-6 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Network Topologies Network topologies: (a) crossbar; (b) bus; (c) ring; (d) mesh; (e) star; (f) tree; (g) perfect shuffle; (h) hypercube.

10-7 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Crossbar Internal organization of a crossbar.

10-8 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Crosspoint Settings (a) Crosspoint settings for connections 0  3 and 3  0; (b) adjusted settings to accommodate connection 1  1.

10-9 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Three-Stage Clos Network

10-10 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring 12- Channel Three- Stage Clos Network with n = p = 6

10-11 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring 12- Channel Three- Stage Clos Network with n = p = 2

10-12 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring 12-Channel Three-Stage Clos Network with n = p = 4

10-13 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring 12-Channel Three-Stage Clos Network with n = p = 3

10-14 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring C function computes (x 2 + y 2 )  y 2

10-15 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Dependency Graph (a) Control sequence for C program; (b) dependency graph for C program.

10-16 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Matrix Multiplication (a) Problem setup for Ax = b; (b) equations for computing the b i.

10-17 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Matrix Multiplication Dependency Graph

10-18 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring The PowerPC 601 Architecture

10-19 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring 128-Bit IA-64 Instruction Word Each 41 bit instruction consists of three register addresses (each 7 bits = 128 possible registers), a predicate register (6 bits) and the opcode and flags or general purpose register (14 bits, varies by instruction).

10-20 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Itanium Instruction Types

10-21 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Allowable Combinations of IA-64 Instruction Types Assigned to Instruction Slots

10-22 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring IA-64 Instruction Issues Maximum number of IA-64 instructions that can be executed for each pairing of bundles.

10-23 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Intel MMX (MultiMedia eXtensions) Vector addition of eight bytes by the Intel PADDB mm0, mm1 instruction:

10-24 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Intel and Motorola Vector Registers Intel “aliases” the floating point registers as MMX registers. This means that the Pentium’s 8 64-bit floating-point registers do double-duty as MMX registers. Motorola implements bit vector registers as a new set, separate and distinct from the floating-point registers.

10-25 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring MMX and AltiVec Arithmetic Instructions

10-26 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Comparing Two MMX Byte Vectors for Equality

10-27 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Conditional Assignment of an MMX Byte Vector

10-28 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring A PAL Device PLAs and PALs are similar except that the OR gates in a PAL have a fixed number of inputs and the inputs are not programmable. PALs are more prevalent than PLAs because they are easier to manufacture and are less complex.

10-29 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Complex Programmable Logic Device CPLDs are PAL-like or PLA-like blocks that can be combined with programmable interconnections. Commercial CPLDs may contain as many as 200,000 equivalent gates and have over 3,000 macrocells.

10-30 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Field Programmable Gate Array Unlike CPLDs, which employ large logic blocks and fewer interconnection options, FPGAs employ small logic blocks that can be programmably interconnected.

10-31 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Quantum Computing Single-particle interference experiment.

10-32 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Multi-Valued Logic Truth tables for binary and ternary comparison functions:

10-33 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Neural Networks Model of a living neuron, and model of an artificial neuron (below).

10-34 Chapter 10 - Advanced Computer Architecture Computer Architecture and Organization by M. Murdocca and V. Heuring © 2007 M. Murdocca and V. Heuring Artificial Neural Network Example Two simple, feed-forward neural networks with inputs, weights, and thresholds as shown.