326:), FORTRAN was less than well suited to this task. The result was noticeably inelegant and did require a great deal of new learning. Operationally, there was an overhead to transfer computational data into and out of the array, and problems which did not fit the 64x64 matrix imposed additional complexity to handle the boundaries (65x65 was perhaps the worst case!) – but for problems which suited the architecture, it could outperform the current
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However, DAP FORTRAN fell between two conflicting objectives. It needed to effectively exploit the DAP facilities. But also had to be accessible to the scientific computing community whose primary language, with a design closely tied to serial architectures, was FORTRAN. The dialect used was ICL's
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The omitted dimension was taken as 64, the size of one side of the DAP. The speed of arithmetic operations depended strongly on the number of bits in the value. INTEGER*n reserved 8n bits where n is 1 to 8, and REAL*n reserved 8n bits where n is 3 to 8. LOGICAL reserved a single bit.
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DAP FORTRAN was significantly different from either standard FORTRAN and the machine was not capable of accepting or optimising standard FORTRAN programs. On the other hand, compared with other contemporary languages which were by design extensible (notably
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On the negative side - operations were performed using the size of the underlying hardware i.e. on a 64x64 matrix or 64 element vector.
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and had more flexible indexing. In particular it automatically mapped user sized arrays onto the underlying hardware.
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Assignments could be performed under a logical mask so only some elements in the target of an assignment were changed.
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360:. Research monographs in parallel and distributed computing. Pitman.
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In a declaration either one or two extents could be omitted as in:
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standard and had mismatches with both FORTRAN 77 and the older
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2900-series FORTRAN which was based on an early version of the
35:(SIMD) architecture with 64x64 single bit processors.
330:pipeline architectures by two orders of magnitude.
111:C Converge to a Laplace potential in an area
38:DAP FORTRAN had the following major features:
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358:Massively parallel computing with the DAP
19:was an extension of the non IO parts of
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356:Dennis Parkinson; John Litt (1990).
42:It had matrix and vector operations.
390:Fortran programming language family
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385:Concurrent programming languages
333:A later version of the DAP used
33:Single Instruction Multiple Data
57:C Multiply vector by matrix
29:ICL Distributed Array Processor
23:with constructs that supported
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337:instead which was based on
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400:ICL programming languages
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31:(DAP). The DAP had a
25:parallel computing
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335:Fortran-Plus
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17:DAP FORTRAN
379:Categories
339:FORTRAN 77
318:standard.
316:FORTRAN 66
312:FORTRAN 77
156:ITERATIONS
324:ALGOL-68
300:CONTINUE
129:LOGICAL
27:for the
21:FORTRAN
364:
294:RETURN
174:INSIDE
132:INSIDE
273:OLD_P
159:OLD_P
123:OLD_P
114:REAL
60:REAL
362:ISBN
328:Cray
183:0.25
120:(,),
99:MATR
66:(,),
288:EPS
261:ABS
255:MAX
246:,))
138:DO
135:(,)
126:(,)
87:SUM
72:(),
381::
282:LT
276:))
249:IF
231:,)
210:(,
195:(,
108:))
78:()
370:.
297:1
291:)
285:.
279:.
270:-
267:P
264:(
258:(
252:(
243:-
240:(
237:P
234:+
228:+
225:(
222:P
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216:)
213:-
207:P
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201:)
198:+
192:P
189:(
186:*
180:=
177:)
171:(
168:P
165:P
162:=
153:,
150:1
147:=
144:K
141:1
117:P
105:A
102:(
96:*
93:M
90:(
84:=
81:R
75:R
69:V
63:M
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