Re: GLPSOL in webassemby faster than native ?

Hello Andrew !

In this case mean compiling with "-O3 -DNDEBUG -DWITH_SPLAYTREE" on 
Arm7, "-O3 -DNDEBUG -flto -march=native -ffp-contract=off 
-DWITH_SPLAYTREE" on x86_64 and "-O3 -DNDEBUG -flto -DWITH_SPLAYTREE" on 
wasm.

How are the parameters for the cut generations selected ?

Isn't strange that on wasm it's been faster than native ?

Doesn't this difference gives insight to select the parameter differently ?

Cheers !

On 22/9/20 17:56, Andrew Makhorin wrote:
> On Tue, 2020-09-22 at 15:53 +0200, Domingo Alvarez Duarte wrote:
>> Hello again !
>>
>> On an Android phone arm7 32bits Nexux-5 with chrome browser (wasm)
>> solving the "hashi.mod" with "--cuts" takes 98s and without it 909s,
>> using glpsol native compiled within termux takes 497s with "--cuts"
>> and
>> without it 925s.
>
> What does "native" mean? Just changing, for example, optimization level
> of the compiler may essentially change the set of generated cuts and
> thus the solution time.
>
>
>> Arm7 32bits Nexus-5:
>>
>>       wasm "--cuts -m hashi.mod" -> 98s
>>
>>       wasm " -m hashi.mod" -> 909s
>>
>>       native "--cuts -m hashi.mod" -> 497s
>>
>>       native " -m hashi.mod" -> 925s
>>
>>
>> Laptop Linux 64bits I7:
>>
>>       wasm "--cuts -m hashi.mod" -> 8s
>>
>>       wasm " -m hashi.mod" -> 142s
>>
>>       native "--cuts -m hashi.mod" -> 73s
>>
>>       native " -m hashi.mod" -> 55s
>>
>>
>> On arm7 "--cuts" improves the performance in both wasm and native.
>>
>> On x86_64 "--cuts" improves in wasm but degrade in native.
>>
>> I hope this could give hints to improve GLPK solver performance by
>> inspecting the decision's criteria and eventually find a better ones.
>>
>> Anyone can give any idea with this data ?
>>
>> Cheers !
>>
>> On 21/9/20 17:11, Andrew Makhorin wrote:
>>> On Mon, 2020-09-21 at 16:09 +0200, Domingo Alvarez Duarte wrote:
>>>> Hello Andrew !
>>>>
>>>> Are you saying that floating point calculations are more
>>>> efficient/precise in webassembly ?
>>> No. I meant that due to floating-point computations running the same
>>> computer program with the same data as a rule produces different
>>> results
>>> on different platforms.
>>>
>>>> Cheers !
>>>>
>>>> On 21/9/20 15:08, Andrew Makhorin wrote:
>>>>>> Does someone can give a possible explanation ?
>>>>> floating-point computations
>>