Re: [julia-users] Type instability?

On Sun, Dec 13, 2015 at 7:06 PM, Dominique Orban wrote: > I'm writing Julia functions to perform a sparse matrix factorization and I'm > wondering if what I'm observing is a manifestation of type instability. I'm > using Julia 0.4 so I can use @code_warntype, but it's

[julia-users] Type instability?

I'm writing Julia functions to perform a sparse matrix factorization and I'm wondering if what I'm observing is a manifestation of type instability. I'm using Julia 0.4 so I can use @code_warntype, but it's surprisingly quiet and doesn't reveal much (there are no ANYs or UNIONs; the "Variables"

[julia-users] Type instability?

In the Rational.jl https://github.com/JuliaLang/julia/blob/master/base/rational.jl : In Line 8: `num == den == zero(T)` uses `zero(T)` to represent 0 In Line 9: `g = den 0` uses `0` to represent 0 Why this difference? My intuition tells me that in Line 8, it can be replaced by 0 without

Re: [julia-users] Type instability?

There shouldn't be any penalty: julia foo(x) = x == 0 foo (generic function with 1 method) julia foo2(x) = x == zero(x) foo2 (generic function with 1 method) julia @code_llvm foo(3.2) define i1 @julia_foo_21071(double) { top: %1 = fcmp oeq double %0, 0.00e+00 ret i1 %1 } julia

Re: [julia-users] Type instability?

One is being returned, the other isn't. You cannot change line 8 without causing the returned type to depend on the value. On Aug 16, 2015, at 10:10 AM, Sisyphuss zhengwend...@gmail.com wrote: In the Rational.jl : In Line 8: `num == den == zero(T)` uses `zero(T)` to represent 0 In Line

Re: [julia-users] Type instability?

Sorry, yes, I misread the example. They're both fine with just 0. On Aug 16, 2015, at 2:32 PM, Stefan Karpinski stefan.karpin...@gmail.com wrote: One is being returned, the other isn't. You cannot change line 8 without causing the returned type to depend on the value. On Aug 16, 2015,

Re: [julia-users] Type instability?

In your definition I think you meant type stability, not type instability. To be completely explicit, a function is type-stable if you can calculate the return type(s) of all outputs from the types of the inputs. If you have to look at the actual values of the inputs, it's not type-stable.

Re: [julia-users] Type instability?

Hey Tim, Thanks for the answer. I think I meant what I stated in the definition. A function is type instable if return types depend on input types. I guess the question I really want to get an answer to is whether or not functions like this will make it difficult for the compiler to emit

Re: [julia-users] Type instability?

Hey Spencer, A function is defined to be type stable if the return types depend only on the input types. -- John On Jun 30, 2014, at 9:51 AM, Tim Holy tim.h...@gmail.com wrote: In your definition I think you meant type stability, not type instability. To be completely explicit, a

Re: [julia-users] Type instability?

On Monday, June 30, 2014 09:54:43 AM Spencer Lyon wrote: Hey Tim, Thanks for the answer. I think I meant what I stated in the definition. A function is type instable if return types depend on input types. No, that's not right. Think about the + function: if you add a Float64 + Float64, you

Re: [julia-users] Type instability?

Ha, you guys are totally right. Sorry about that Tim, I was wrong there. Thanks for clearing it up, John. On Monday, June 30, 2014 12:56:10 PM UTC-4, John Myles White wrote: Hey Spencer, A function is defined to be type stable if the return types depend only on the input types. --