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March 17, 2013 Changing -O to be equivalent to -O3 | ||||
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 | See: https://github.com/ldc-developers/ldc/pull/315 Any further opinions? David | |||
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ReplyMarch 18, 2013 Re: Changing -O to be equivalent to -O3 | ||||
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 Posted in reply to David Nadlinger | On Sunday, 17 March 2013 at 18:33:57 UTC, David Nadlinger wrote:
> See: https://github.com/ldc-developers/ldc/pull/315
>
> Any further opinions?
>
> David
why not O5?
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March 18, 2013 Re: Changing -O to be equivalent to -O3 | ||||
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Posted in reply to John Colvin | On Monday, 18 March 2013 at 02:25:17 UTC, John Colvin wrote:
> On Sunday, 17 March 2013 at 18:33:57 UTC, David Nadlinger wrote:
>> See: https://github.com/ldc-developers/ldc/pull/315
>>
>> Any further opinions?
>>
>> David
>
> why not O5?
Because -O5 is the same as -O3 right now. I thought this was documented somewhere, but apparently this is not the case. Do you want to fix it? ;)
David
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March 18, 2013 Re: Changing -O to be equivalent to -O3 | ||||
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 Posted in reply to David Nadlinger | On Sunday, 17 March 2013 at 18:33:57 UTC, David Nadlinger wrote:
> See: https://github.com/ldc-developers/ldc/pull/315
>
> Any further opinions?
>
> David
What is the current behavior ? What is clang's behavior ?
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March 18, 2013 Re: Changing -O to be equivalent to -O3 | ||||
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Posted in reply to David Nadlinger | On Monday, 18 March 2013 at 12:42:10 UTC, David Nadlinger wrote:
> On Monday, 18 March 2013 at 02:25:17 UTC, John Colvin wrote:
>> On Sunday, 17 March 2013 at 18:33:57 UTC, David Nadlinger wrote:
>>> See: https://github.com/ldc-developers/ldc/pull/315
>>>
>>> Any further opinions?
>>>
>>> David
>>
>> why not O5?
>
> Because -O5 is the same as -O3 right now. I thought this was documented somewhere, but apparently this is not the case. Do you want to fix it? ;)
>
> David
Far from being documented as equivalent to O3, ldc2 --help says O4 and O5 are "link-time optimization" Is this also incorrect?
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March 18, 2013 Re: Changing -O to be equivalent to -O3 | ||||
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Posted in reply to John Colvin | On Monday, 18 March 2013 at 16:39:14 UTC, John Colvin wrote:
> Far from being documented as equivalent to O3, ldc2 --help says O4 and O5 are "link-time optimization" Is this also incorrect?
Well, it's correct in so far as they were intended for LTO. But as far as I remember, they were never implemented, and certainly aren't right now.
David
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May 27, 2013 Re: Changing -O to be equivalent to -O3 | ||||
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 Posted in reply to David Nadlinger | Am Sun, 17 Mar 2013 19:33:54 +0100 schrieb "David Nadlinger" <see@klickverbot.at>: > See: https://github.com/ldc-developers/ldc/pull/315 > > Any further opinions? > > David My opinion is to benchmark. How much longer is the compile time? How many programs benefit? How many bad cases are there where the optimizations slow down the executable by excessive unrolling or similar? Last time I tried LDC's optimizations I saw a minor slowdown in one program, and overall little gain (compared to the more substantial gains of -O3 in GDC). -- Marco | |||
May 27, 2013 Re: Changing -O to be equivalent to -O3 | ||||
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Posted in reply to Marco Leise | P.S.: If this is for the ldmd wrapper only I agree with
the arguments for merging the pull request. I.e.: +1
--
Marco
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