diff --git a/src/generic.jl b/src/generic.jl
index 2b03b249..de37f081 100644
--- a/src/generic.jl
+++ b/src/generic.jl
@@ -1358,8 +1358,15 @@ ishermitian(x::Number) = (x == conj(x))
 _iszero(V) = iszero(V)
 # A Base.FastContiguousSubArray view of a StridedArray
 FastContiguousSubArrayStrided{T,N,P<:StridedArray,I<:Tuple{AbstractUnitRange, Vararg{Any}}} = Base.SubArray{T,N,P,I,true}
-# using mapreduce instead of all permits vectorization
-_iszero(V::FastContiguousSubArrayStrided) = mapreduce(iszero, &, V, init=true)
+# Reducing over the entire array instead of calling `all` within `iszero` permits vectorization
+# The loop is equivalent to a mapreduce, but is faster to compile
+function _iszero(V::FastContiguousSubArrayStrided)
+    ret = true
+    for i in eachindex(V)
+        ret &= iszero(@inbounds V[i])
+    end
+    ret
+end
 
 """
     istriu(A::AbstractMatrix, k::Integer = 0) -> Bool