Faster matrix sqrt for upper triangular matrices. (JuliaLang#31100)

Replacing Val(::Bool) in an argument list with an explicit if makes the call type stable. The issue was discussed in JuliaLang#31007.
inkydragon · May 2, 2020 · 68c8708 · 68c8708
1 parent f36036c
commit 68c8708
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/stdlib/LinearAlgebra/src/triangular.jl b/stdlib/LinearAlgebra/src/triangular.jl
@@ -2586,7 +2586,13 @@ function sqrt(A::UpperTriangular)
  end
  end
  end
- sqrt(A,Val(realmatrix))
+ # Writing an explicit if instead of using Val(realmatrix) below
+ # makes the calls to sqrt(::UpperTriangular,::Val) type stable.
+ if realmatrix
+ return sqrt(A,Val(true))
+ else
+ return sqrt(A,Val(false))
+ end
 end
 function sqrt(A::UpperTriangular{T},::Val{realmatrix}) where {T,realmatrix}
  B = A.data