diff --git a/src/HashIndex.jl b/src/HashIndex.jl
index ac9bfe3..0492ffd 100644
--- a/src/HashIndex.jl
+++ b/src/HashIndex.jl
@@ -32,6 +32,26 @@ function Base.count(f::Fix2{typeof(isequal)}, a::AcceleratedArray{<:Any, <:Any,
     end
 end
 
+function Base.count(f::Fix2{typeof(==)}, a::AcceleratedArray{<:Any, <:Any, <:Any, <:HashIndex})
+    out = 0
+
+    for x in other_equal(f.x) # Search for other things that might be == but not isequal (like -0.0)
+        (hasindex, token) = gettoken(a.index.dict, x)
+        @inbounds if hasindex
+            out += length(@inbounds gettokenvalue(a.index.dict, token))
+        end
+    end
+
+    if f(f.x) # Exclude things that are not == to themselves (like NaN)
+        (hasindex, token) = gettoken(a.index.dict, f.x)
+        if hasindex
+            return out + length(@inbounds gettokenvalue(a.index.dict, token))
+        end
+    end
+
+    return out
+end
+
 function Base.findall(f::Fix2{typeof(isequal)}, a::AcceleratedArray{<:Any, <:Any, <:Any, <:HashIndex})
     (hasindex, token) = gettoken(a.index.dict, f.x)
     if hasindex
@@ -41,6 +61,33 @@ function Base.findall(f::Fix2{typeof(isequal)}, a::AcceleratedArray{<:Any, <:Any
     end
 end
 
+function Base.findall(f::Fix2{typeof(==)}, a::AcceleratedArray{<:Any, <:Any, <:Any, <:HashIndex})
+    out = Vector{keytype(a)}()
+    n_matches = 0
+
+    for x in other_equal(f.x) # Search for other things that might be == but not isequal (like -0.0)
+        (hasindex, token) = gettoken(a.index.dict, x)
+        @inbounds if hasindex
+            append!(out, @inbounds gettokenvalue(a.index.dict, token))
+            n_matches += 1
+        end
+    end
+    
+    if f(f.x) # Exclude things that are not == to themselves (like NaN)
+        (hasindex, token) = gettoken(a.index.dict, f.x)
+        if hasindex
+            append!(out, @inbounds gettokenvalue(a.index.dict, token))
+            n_matches += 1
+        end
+    end
+
+    if n_matches > 1
+        sort!(out)
+    end
+
+    return out
+end
+
 # TODO: findall for arbitrary predicates by just checking each unique key? (Sometimes faster, sometimes slower?)
 
 function Base.findfirst(f::Fix2{typeof(isequal)}, a::AcceleratedArray{<:Any, <:Any, <:Any, <:HashIndex})
diff --git a/src/predicates.jl b/src/predicates.jl
index e679898..1cc3cf2 100644
--- a/src/predicates.jl
+++ b/src/predicates.jl
@@ -58,3 +58,16 @@ if VERSION < v"1.2.0-DEV.257"
     Base.:(>=)(x) = Fix2(>=, x)
     Base.:(!=)(x) = Fix2(!=, x)
 end
+
+# Search for other things that are == but not isequal (for example -0.0)
+other_equal(::Any) = ()
+other_equal(x::AbstractFloat) = isequal(x, 0.0) ? MaybeVector(convert(typeof(x), -0.0)) : isequal(x, -0.0) ? MaybeVector(convert(typeof(x), 0.0)) : MaybeVector{typeof(x)}()
+
+# ismissing
+Base.count(f::typeof(ismissing), a::AcceleratedArray) = count(isequal(missing), a)
+Base.findall(f::typeof(ismissing), a::AcceleratedArray) = findall(isequal(missing), a)
+Base.findfirst(f::typeof(ismissing), a::AcceleratedArray) = findfirst(isequal(missing), a)
+Base.findlast(f::typeof(ismissing), a::AcceleratedArray) = findlast(isequal(missing), a)
+Base.filter(f::typeof(ismissing), a::AcceleratedArray) = filter(isequal(missing), a)
+
+# TODO isnan, iszero, isone, isfinite (all are slightly strange when considering things like Complex, Matrix and String)
\ No newline at end of file