Cypress CSC-1200T Betriebsanweisung Seite 45
- Seite / 124
- Inhaltsverzeichnis
- LESEZEICHEN
Bewertet. / 5. Basierend auf Kundenbewertungen
Chapter 5. Fortran programming 45
You can improve the performance by padding the arrays so that the
corresponding elements do not map to the same cache lines:
INTEGER, PARAMETER :: n = 4096, pad = 8
REAL, DIMENSION(n+pad) :: a, b
REAL, DIMENSION(n) :: c
COMMON /my_block/ a, b, c
The rest of the code is identical. The padding can also be done using
extra arrays:
INTEGER, PARAMETER :: n = 4096, pad = 8
REAL, DIMENSION(n) :: a, b, c
REAL, DIMENSION(pad) :: temp1, temp2
COMMON /my_block/ a, temp1, b, temp2, c
After this, the read operations for arrays a and b do not map to the
same DCACHE and SCACHE lines, and the write operations of the c(i)
elements do not map to these cache lines. This makes the code run a lot
faster!
Similar techniques can also be used with arrays of two or more dimen-
sions.
5.7 Compiler directives
In addition to using compiler options, you can use the so-called compiler
directives to control the compilation process. There are directives which
help in code optimization, memory usage, checking array bounds etc.
Table 5.4 lists the most useful compiler directives.
Directive Explanation
free, fixed Specifying source form
[no]bounds [array] Array bounds checking
integer=n Specifying integer length
name (fortran_name="ext_name") Naming external routines
[no]bl Bottom loading operands
[no]split Loop splitting
[no]unroll [n] Loop unrolling (n copies)
cache_align var Align on cache line boundaries
symmetric [var, ...] Declaring local addressing
Table 5.4: Some compiler directives for the f90 command.
Directives are written into the source code as special comments, and the
CF90 compiler interprets them in the compilation phase.
Here is a short example:
- Cray T3E 1
- User’s Guide 1
- Cray T3E User’s Guide 3 3
- Contents 4
- Contents 5 5
- B Glossary 113 6
- Bibliography 118 6
- Index 120 6
- Introduction 7
- 1.2 Usage policy 8
- 1.3 Overview of the system 9
- 1.4 Programming environment 9
- 10 Cray T3E User’s Guide 10
- Chapter 1. Introduction 11 11
- 12 Cray T3E User’s Guide 12
- Using the Cray T3E at CSC 13
- 2.2 Files 14
- 2.3 Editing files 16
- 2.5 Executing in batch mode 17
- 2.6 More information 18
- The Cray T3E system 20
- 3.2 Distributed memory 21
- 3.3 Processing elements 21
- 3.4 Processor architecture 23
- 3.5 Local memory hierarchy 24
- 26 Cray T3E User’s Guide 26
- Processing Element 27
- I/O Controller 27
- Interconnection 27
- Network 27
- 3.9 File systems 28
- 3.10 Resource monitoring 29
- 30 Cray T3E User’s Guide 30
- 3.11 More information 31
- Program development 32
- 4.3.1 BLAS 34
- 4.3.2 LAPACK 34
- 4.3.3 BLACS 35
- 4.3.4 PBLAS and ScaLAPACK 35
- 4.3.5 Details 35
- 36 Cray T3E User’s Guide 36
- 4.6 More information 38
- Fortran programming 40
- 5.2 Basic usage 41
- 5.4 Compiler options 42
- 5.5 Optimization options 42
- 5.6 Optimizing for cache 44
- 5.7 Compiler directives 45
- 5.8 Fortran 90 modules 48
- 5.9 Source code preprocessing 49
- 5.10 More information 51
- C and C++ programming 52
- 6.2 The C compiler 53
- 6.3 Calling Fortran from C 54
- 6.4 C compiler options 55
- #pragma _CRI symmetric var 59
- #pragma _CRI unroll [n] 59
- 6.6 The C++ compiler 61
- 6.7 More information 61
- Interprocess communication 62
- 7.2.1 Format of the MPI calls 63
- 7.2.2 Some MPI routines 64
- 7.2.3 An example of using MPI 64
- 7.2.5 MPI data types 67
- 7.3.1 Using PVM on the T3E 68
- #include <mpp/shmem.h> 71
- INCLUDE ’mpp/shmem.fh’ 71
- 7.4.2 Data addresses 72
- 7.4.4 Reduction routines 74
- 7.4.6 Example of using SHMEM 76
- 78 Cray T3E User’s Guide 78
- 0:c= 10121416 78
- 1:c= 2468 78
- 80 Cray T3E User’s Guide 80
- Batch queuing system 81
- 82 Cray T3E User’s Guide 82
- # QSUB -l p_mpp_t=7000 82
- 8.3 Status of the NQE job 83
- 84 Cray T3E User’s Guide 84
- 8.4 Deleting an NQE batch job 86
- 8.5 Queues 86
- 8.6 More information 87
- Programming tools 88
- 9.2 Program Browser 89
- 9.3 Debugging programs 92
- 9.3.2 Examining core files 93
- 94 Cray T3E User’s Guide 94
- 9.4.1 MPP Apprentice 95
- 9.4.2 The appview command 98
- 9.4.3 PAT 98
- 9.5.1 The VAMPIRtrace library 100
- 102
- 9.5.3 More information 103
- Miscellaneous notes 104
- 10.1.3 The CPU clock timer 105
- 10.1.4 Example of timing 106
- 108 Cray T3E User’s Guide 108
- 10.4 More information 110
- About CSC 111
- 112 Cray T3E User’s Guide 112
- Glossary 113
- 114 Cray T3E User’s Guide 114
- Appendix B. Glossary 115 115
- Metacomputer Environment 116
- Bibliography 118
Verwandte Produkte und Handbücher für Empfänger Cypress CSC-1200T
Empfänger Cypress COH-Tx Bedienungsanleitung
(12 Seiten)
(12 Seiten)
Empfänger Cypress CWHDI-TX Spezifikationen
(12 Seiten)
(12 Seiten)
Empfänger Cypress CH-107 TX Bedienungsanleitung
(16 Seiten)
(16 Seiten)
Empfänger Cypress CH-506RX Spezifikationen
(16 Seiten)
(16 Seiten)
Empfänger Cypress COH-Tx Spezifikationen
(16 Seiten)
(16 Seiten)
Empfänger Cypress COH-Rx1 Spezifikationen
(16 Seiten)
(16 Seiten)
Empfänger Cypress CWHDI-RX Spezifikationen
(12 Seiten)
(12 Seiten)
Empfänger Cypress CSC-1200T Bedienungsanleitung
(12 Seiten)
(12 Seiten)
Empfänger Cypress CA-DVI100R Bedienungsanleitung
(12 Seiten)
(12 Seiten)
Empfänger Cypress CH-506RX Spezifikationen
(24 Seiten)
(24 Seiten)
© 2020, manymanuals.de. Alle Rechte vorbehalten. | 0.096 s |
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Kommentare zu diesen Handbüchern