A few test fixes

Author: chriselrod

src/cholesky.jl

@@ -18,8 +18,8 @@ end
     end
 end
 # x < zero(x) is check used in `sqrt`, letting LLVM eliminate that check and remove error code.
-@inline _nonpdcheck(x::Real) = x < zero(x)
-@inline _nonpdcheck(x) = false
+@inline _nonpdcheck(x::Real) = x ≥ zero(x)
+@inline _nonpdcheck(x) = x == x
 
 @generated function _cholesky(::Size{S}, A::StaticMatrix{M,M}, check::Bool) where {S,M}
     @assert (M,M) == S
@@ -38,7 +38,8 @@ end
         end
         L_n_n = Symbol(:L_,n,:_,n)
         L_n_n_ltz = Symbol(:L_,n,:_,n,:_,:ltz)
-        push!(q.args, :($L_n_n = _nonpdcheck($L_n_n) ? (return _chol_failure(A, $n, check)) : sqrt($L_n_n)))
+        push!(q.args, :(_nonpdcheck($L_n_n) || return _chol_failure(A, $n, check)))
+        push!(q.args, :($L_n_n = Base.FastMath.sqrt_fast($L_n_n)))
         Linv_n_n = Symbol(:Linv_,n,:_,n)
         push!(q.args, :($Linv_n_n = inv($L_n_n)))
         for m ∈ n+1:M

test/chol.jl

@@ -34,15 +34,6 @@ using LinearAlgebra: PosDefException
             m_a = randn(elty, 4,4)
             #non hermitian
             @test_throws PosDefException cholesky(SMatrix{4,4}(m_a))
-            nonpd = SVector{4}(@view(m_a[:,1])) |> x -> x * x'
-            if elty <: Real
-                @test_throws PosDefException cholesky(nonpd)
-                @test !issuccess(cholesky(nonpd,check=false))
-                @test_throws PosDefException cholesky(Hermitian(nonpd))
-                @test !issuccess(cholesky(Symmetric(nonpd),check=false))
-            else
-                @test issuccess(cholesky(Hermitian(nonpd),check=false))
-            end
 
             m_a = m_a*m_a'
             m = SMatrix{4,4}(m_a)
@@ -96,6 +87,21 @@ using LinearAlgebra: PosDefException
             @test (@inferred c \ v) isa SVector{3,elty}
             @test c \ v ≈ c_a \ v_a
         end
+
+        @testset "Check" begin
+            for i ∈ [1,3,7,25]
+                x = SVector(ntuple(elty, i))
+                nonpd = x * x'
+                if i > 1
+                    @test_throws PosDefException cholesky(nonpd)
+                    @test !issuccess(cholesky(nonpd,check=false))
+                    @test_throws PosDefException cholesky(Hermitian(nonpd))
+                    @test !issuccess(cholesky(Hermitian(nonpd),check=false))
+                else
+                    @test issuccess(cholesky(Hermitian(nonpd),check=false))
+                end
+            end
+        end
     end
 
     @testset "static blockmatrix" for i = 1:10