HP 3000 Manuals HP 3000 Manuals
Summary of Optimization Parameters on HP-UX
The HP C optimization parameters are summarized in Table 4-3 .
Table 4-3. HP C Optimization Parameters
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| | | |
| Option | What It Does | Level |
| | | of Opt |
| | | |
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| | | |
| +O[no]aggressive | The +O[no]aggressive option enables optimizations | 2, 3, 4 |
| | that can result in significant performance | |
| | improvement, but that can change a program's | |
| | behavior. These optimizations include newly released | |
| | optimizations and the optimizations invoked by the | |
| | following advanced optimization options: (1) | |
| | | |
| | * +Osignedpointers | |
| | * +Oregionsched | |
| | * +Oentrysched | |
| | * +Onofltacc | |
| | * +Onoparmsoverlap | |
| | * +Olibcalls | |
| | * +Onoinitcheck | |
| | | |
| | The default is +Onoaggressive. | |
| | | |
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| | | |
| +O[no]all | The +Oall option performs maximum optimization, | 4 |
| | including aggressive optimizations and optimizations | |
| | that can significantly increase compile time and | |
| | memory usage. | |
| | | |
| | The default is +Onoall. | |
| | | |
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Table 4-3. HP C Optimization Parameters (cont.)
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| | | |
| Option | What It Does | Level |
| | | of Opt |
| | | |
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| | | |
| +O[no]conservative | The +O[no]conservative option causes the optimizer to | 2, 3, 4 |
| | make conservative assumptions about the code when | |
| | optimizing it. Use +Oconservative when conservative | |
| | assumptions are necessary due to the coding style, as | |
| | with non-standard conforming programs. | |
| | | |
| | The +Oconservative option relaxes the optimizer's | |
| | assumptions about the target program. This option is | |
| | equivalent to +Onoaggressive. | |
| | | |
| | The default is +Onoconservative. | |
| | | |
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| | | |
| +O[no]limit | The +Olimit option suppresses optimizations that | 2, 3, 4 |
| | significantly increase compile-time or that can | |
| | consume a lot of memory. | |
| | | |
| | The +Onolimit option allows optimizations to be | |
| | performed regardless of their effect on compile-time | |
| | or memory usage. | |
| | | |
| | The default is +Olimit. | |
| | | |
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| | | |
| +O[no]size | The +Osize option suppresses optimizations that | 2, 3, 4 |
| | significantly increase code size. | |
| | | |
| | The +Onosize option does not prevent optimizations | |
| | that can increase code size. | |
| | | |
| | The default is +Onosize. | |
| | | |
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(1) See Table 4-4 for details about advanced optimization options.