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Par ce dispositif a également d'autres instructions :
Facilité d'utilisation
Accelerator Performance Issues
Minimizing Code Generation
• Accelerate programs with the ProcDebug debugging option (the default) instead of
the StmtDebug option.
• Accelerate a program’s user library. After you accelerate the user library,
accelerate the program again, specifying the accelerated user library with the
UserLib option. Refer to Accelerating User Libraries and Shared Run-Time
Libraries on page 4-9 for details.
Minimizing Code Generation
Accelerator elementary options determine whether or not the Accelerator generates
code to account for specific program variances or constructs. The Accelerator
elementary options generate additional RISC code to account for specific program
variances or constructs when set to “on”; they do not generate additional code when
set to “off.”
To increase the performance of a program that does not contain a specific variance or
construct, you can set the corresponding elementary option to “off.” HP recommends
that you use the Accelerator default settings — the Common super option. Accelerator
options that are set to “on” by default are intended primarily for accelerating the
operating system; most customer applications do not benefit significantly from setting
these options “off.” However, if you are willing to thoroughly examine your program,
you might be able to increase program performance by setting these options to “off.”
Each of the Accelerator elementary options is described in Section 5, Setting
Accelerator Options. Refer to this section for details about when you can safely set an
option to “off.”TheAtomic_On option has the greatest negative effect on performance.
In some cases, the InheritsCC_On and OvTrap_On options can moderately affect
performance. TheTruncateIndexing_On and SafeAliasingRules_On options usually
have little effect on performance.
Minimizing Transitions Into TNS Code
The Accelerator produces for each TNS instruction its functional equivalent for TNS/R
systems, in the form of either RISC instructions or a call to millicode. Millicode
implements various TNS low-level functions such as exception handling, real-time
translation routines, and library routines that implement the TNS instruction set.
Millicode is functionally equivalent to TNS microcode.
When executing TNS code, millicode decodes each of TNS instructions and executes
RISC instructions to perform the appropriate operations and to update all the TNS
registers. When executing accelerated code, RISC instructions execute directly.
Accelerated code maintains only the portions of the TNS machine state that are
actually required by the program, thus increasing the execution speed.
Some TNS instruction sequences cannot be turned into optimized RISC instructions by
the Accelerator because their exact meaning cannot be determined until run-time. In
such cases, the TNS instructions forming the sequence execute in their original form;
this is equivalent to running TNS object code on a TNS/R system. A program is said
Accelerator Manual — 527303-003
6 -2
... Ce manuel est également adapté pour les modèles :
Ordinateurs - HP Integrity NonStop J-Series (556.83 kb)
Ordinateurs - HP NonStop G-Series (556.83 kb)
Ordinateurs - HP NonStop L-Series (556.83 kb)