I still don't understand the details of the new functions in v0.5. but I'd
be inclined to think this test depends on whether you're on v0.4.6 or
v0.5.0.
On Tuesday, August 2, 2016 at 12:53:27 PM UTC+8, Greg Plowman wrote:
>
> I get timing/allocations the other way around. (test1, hard-coded version
> is fast without allocation)
> @code_warntype for test2 shows type-instability for s (because return type
> cannot be inferred for f1)
>
>
> On Tuesday, August 2, 2016 at 2:33:24 PM UTC+10, Christoph Ortner wrote:
>
>> Below are two tests, in the first a simple polynomial is "hard-coded", in
>> the second it is passed as a function. I would expect the two to be
>> equivalent, but the second case is significantly faster. Can anybody
>> explain what is going on? @code_warntype doesn't show anything that would
>> explain it?
>>
>> function test1(N)
>>
>> r = 0.234; s = 0.0
>> for n = 1:N
>> s += r^3 + r^5
>> end
>> return s
>> end
>>
>>
>> function test2(N, f1)
>> r = 0.234; s = 0.0
>> for n = 1:N
>> s += f1(r)
>> end
>> return s
>> end
>>
>>
>> g1(r) = r^3 + r^5
>>
>>
>> test1(10)
>> test2(10, g1)
>>
>>
>> println("Test1: hard-coded functions")
>> @time test1(1_000_000)
>> @time test1(1_000_000)
>> @time test1(1_000_000)
>>
>>
>> println("Test2: pass functions")
>> @time test2(1_000_000, g1)
>> @time test2(1_000_000, g1)
>> @time test2(1_000_000, g1)
>>
>>
>>
>>
>> # $ julia5 weird_test2.jl
>> # Test1: hard-coded functions
>> # 0.086683 seconds (4.00 M allocations: 61.043 MB, 50.75% gc time)
>> # 0.142487 seconds (4.00 M allocations: 61.035 MB, 76.91% gc time)
>> # 0.025388 seconds (4.00 M allocations: 61.035 MB, 4.28% gc time)
>> # Test2: pass functions
>> # 0.000912 seconds (5 allocations: 176 bytes)
>> # 0.000860 seconds (5 allocations: 176 bytes)
>> # 0.000846 seconds (5 allocations: 176 bytes)
>>
>>
>>
>>
>>
>>
