diff --git a/src/Ops.jl b/src/Ops.jl
index b953e1c59..46283fcde 100644
--- a/src/Ops.jl
+++ b/src/Ops.jl
@@ -76,6 +76,25 @@ end
     return TracedRArray{T,N}((), res, size(x))
 end
 
+## This is somewhat a hack because I can't seem to find the corresponding mlir
+## DenseElementsAttribute functions (also our optimizations will run a pass converting this
+## to a single operation)
+for T in (:F8E5M2, :F8E4M3FN, :F8E4M3B11FNUZ, :F8E5M2FNUZ, :F8E4M3FNUZ)
+    @eval @noinline function constant(
+        x::DenseArray{<:Reactant.$(T),N};
+        location=mlir_stacktrace("constant", @__FILE__, @__LINE__),
+    ) where {N}
+        value = MLIR.IR.DenseElementsAttribute(
+            map(Float16 ∘ Base.Fix2(getproperty, :val), x)
+        )
+        output = mlir_type(TracedRArray{Float16,N}, size(x))
+        res = MLIR.IR.result(stablehlo.constant(; output, value, location))
+        return convert(
+            TracedRArray{eltype(x),N}, TracedRArray{Float16,N}((), res, size(x)); location
+        )
+    end
+end
+
 @noinline function constant(
     x::T; location=mlir_stacktrace("constant", @__FILE__, @__LINE__)
 ) where {T<:Number}
diff --git a/src/PrimitiveTypes.jl b/src/PrimitiveTypes.jl
index b547156ad..a60c4a62d 100644
--- a/src/PrimitiveTypes.jl
+++ b/src/PrimitiveTypes.jl
@@ -1,25 +1,29 @@
+# The types listed in this file are the ones present in StableHLO specification.
+
 # These only exist for the purpose of lowering. Since `ReactantPrimitive` is a fixed set of
 # types, users can use these to convert their types to the primitive types supported by
 # Reactant.
 for T in (:F8E5M2, :F8E4M3FN, :F8E4M3B11FNUZ, :F8E5M2FNUZ, :F8E4M3FNUZ)
     @eval begin
-        primitive type $(T) <: AbstractFloat 8 end
+        struct $(T){inT} <: AbstractFloat
+            val::inT
+        end
 
-        Base.promote_rule(::Type{$(T)}, ::Type{Float16}) = Float16
-        Base.promote_rule(::Type{Float16}, ::Type{$(T)}) = Float16
+        Base.promote_rule(::Type{<:$(T)}, ::Type{Float16}) = Float16
+        Base.promote_rule(::Type{Float16}, ::Type{<:$(T)}) = Float16
 
-        Base.promote_rule(::Type{$(T)}, ::Type{Float32}) = Float32
-        Base.promote_rule(::Type{Float32}, ::Type{$(T)}) = Float32
+        Base.promote_rule(::Type{<:$(T)}, ::Type{Float32}) = Float32
+        Base.promote_rule(::Type{Float32}, ::Type{<:$(T)}) = Float32
 
-        Base.promote_rule(::Type{$(T)}, ::Type{Float64}) = Float64
-        Base.promote_rule(::Type{Float64}, ::Type{$(T)}) = Float64
+        Base.promote_rule(::Type{<:$(T)}, ::Type{Float64}) = Float64
+        Base.promote_rule(::Type{Float64}, ::Type{<:$(T)}) = Float64
 
-        Base.promote_rule(::Type{$(T)}, ::Type{<:Integer}) = $(T)
-        Base.promote_rule(::Type{<:Integer}, ::Type{$(T)}) = $(T)
+        Base.promote_rule(::Type{<:$(T){inT}}, ::Type{<:Integer}) where {inT} = $(T){inT}
+        Base.promote_rule(::Type{<:Integer}, ::Type{<:$(T){inT}}) where {inT} = $(T){inT}
 
         @static if isdefined(Core, :BFloat16)
-            Base.promote_rule(::Type{$(T)}, ::Type{Core.BFloat16}) = Core.BFloat16
-            Base.promote_rule(::Type{Core.BFloat16}, ::Type{$(T)}) = Core.BFloat16
+            Base.promote_rule(::Type{<:$(T)}, ::Type{Core.BFloat16}) = Core.BFloat16
+            Base.promote_rule(::Type{Core.BFloat16}, ::Type{<:$(T)}) = Core.BFloat16
         end
     end
 end
@@ -36,9 +40,9 @@ else
     const ReactantFloat = Union{Float16,Float32,Float64,Base.uniontypes(ReactantFloat8)...}
 end
 
-const ReactantComplexFloat = Union{[Complex{T} for T in Base.uniontypes(ReactantFloat)]...}
+const ReactantComplexFloat = Union{Complex{Float32}, Complex{Float64}}
 
-const ReactantInt = Union{Int8,UInt8,Int16,UInt16,Int32,UInt32,Int64,UInt64,Int128,UInt128}
+const ReactantInt = Union{Int8,UInt8,Int16,UInt16,Int32,UInt32,Int64,UInt64}
 
 const ReactantComplexInt = Union{[Complex{T} for T in Base.uniontypes(ReactantInt)]...}
 
@@ -53,7 +57,7 @@ const ReactantPrimitive = Union{
     Base.uniontypes(ReactantComplexFloat)...,
 }
 
-to_reactant_primitive(v::T) where {T} = reinterpret(reactant_primitive(T), v)
+to_reactant_primitive(v::T) where {T} = reactant_primitive(T)(v)
 reactant_primitive(::Type{T}) where {T} = nothing
 
 for T in Base.uniontypes(ReactantPrimitive)
diff --git a/src/TracedRNumber.jl b/src/TracedRNumber.jl
index bbbb386f9..d81fe1c97 100644
--- a/src/TracedRNumber.jl
+++ b/src/TracedRNumber.jl
@@ -12,7 +12,7 @@ Base.zero(::TracedRNumber{T}) where {T} = TracedUtils.promote_to(TracedRNumber{T
 Base.one(::TracedRNumber{T}) where {T} = TracedUtils.promote_to(TracedRNumber{T}, one(T))
 Base.collect(x::TracedRNumber{T}) where {T} = TracedRArray{T,0}((), x.mlir_data, ())
 
-function Base.eps(::Type{TracedRNumber{T}}) where {T}
+function Base.eps(::Type{<:TracedRNumber{T}}) where {T}
     return TracedUtils.promote_to(TracedRNumber{T}, eps(T))
 end
 
@@ -36,24 +36,26 @@ end
 
 Base.only(A::TracedRNumber{T}) where {T} = A
 
-function Base.promote_rule(::Type{TracedRNumber{T}}, ::Type{TracedRNumber{S}}) where {T,S}
+function Base.promote_rule(
+    ::Type{<:TracedRNumber{T}}, ::Type{<:TracedRNumber{S}}
+) where {T,S}
     return TracedRNumber{Base.promote_type(T, S)}
 end
 
 # Bool has special promotion rules in Base
-function Base.promote_rule(::Type{Bool}, ::Type{TracedRNumber{T}}) where {T}
+function Base.promote_rule(::Type{Bool}, ::Type{<:TracedRNumber{T}}) where {T}
     return TracedRNumber{T}
 end
 
-function Base.promote_rule(::Type{TracedRNumber{T}}, ::Type{Bool}) where {T}
+function Base.promote_rule(::Type{<:TracedRNumber{T}}, ::Type{Bool}) where {T}
     return TracedRNumber{T}
 end
 
-function Base.promote_rule(::Type{T}, ::Type{TracedRNumber{S}}) where {T,S}
+function Base.promote_rule(::Type{T}, ::Type{<:TracedRNumber{S}}) where {T,S}
     return TracedRNumber{Base.promote_type(T, S)}
 end
 
-function Base.promote_rule(::Type{TracedRNumber{T}}, ::Type{S}) where {T,S}
+function Base.promote_rule(::Type{<:TracedRNumber{T}}, ::Type{S}) where {T,S}
     return TracedRNumber{Base.promote_type(T, S)}
 end
 
@@ -67,7 +69,7 @@ function TracedRNumber{T}(x::Number) where {T}
     return TracedUtils.promote_to(TracedRNumber{unwrapped_eltype(T)}, x)
 end
 
-function TracedUtils.promote_to(::Type{TracedRNumber{T}}, rhs) where {T}
+function TracedUtils.promote_to(::Type{<:TracedRNumber{T}}, rhs) where {T}
     if rhs isa TracedRNumber
         rhs isa TracedRNumber{T} && return rhs
         return Ops.convert(TracedRNumber{T}, rhs)
diff --git a/src/XLA.jl b/src/XLA.jl
index 1b3c2b951..ef217d2f5 100644
--- a/src/XLA.jl
+++ b/src/XLA.jl
@@ -357,11 +357,11 @@ end
 @inline primitive_type(::Type{Float16}) = 10
 @inline primitive_type(::Type{Float32}) = 11
 
-@inline primitive_type(::Type{Reactant.F8E5M2}) = 19
-@inline primitive_type(::Type{Reactant.F8E4M3FN}) = 20
-@inline primitive_type(::Type{Reactant.F8E4M3B11FNUZ}) = 23
-@inline primitive_type(::Type{Reactant.F8E5M2FNUZ}) = 24
-@inline primitive_type(::Type{Reactant.F8E4M3FNUZ}) = 25
+@inline primitive_type(::Type{<:Reactant.F8E5M2}) = 19
+@inline primitive_type(::Type{<:Reactant.F8E4M3FN}) = 20
+@inline primitive_type(::Type{<:Reactant.F8E4M3B11FNUZ}) = 23
+@inline primitive_type(::Type{<:Reactant.F8E5M2FNUZ}) = 24
+@inline primitive_type(::Type{<:Reactant.F8E4M3FNUZ}) = 25
 
 @static if isdefined(Core, :BFloat16)
     @inline primitive_type(::Type{Core.BFloat16}) = 16
diff --git a/src/mlir/IR/Type.jl b/src/mlir/IR/Type.jl
index 2b09cfcef..4d4508dde 100644
--- a/src/mlir/IR/Type.jl
+++ b/src/mlir/IR/Type.jl
@@ -196,7 +196,7 @@ Type(::Core.Type{Float64}; context::Context=context()) = Type(API.mlirF64TypeGet
 
 Creates a f8e5m2 type in the given context. The type is owned by the context.
 """
-function Type(::Core.Type{Reactant.F8E5M2}; context::Context=context())
+function Type(::Core.Type{<:Reactant.F8E5M2}; context::Context=context())
     return Type(API.mlirFloat8E5M2TypeGet(context))
 end
 
@@ -205,7 +205,7 @@ end
 
 Creates a f8e4m3fn type in the given context. The type is owned by the context.
 """
-function Type(::Core.Type{Reactant.F8E4M3FN}; context::Context=context())
+function Type(::Core.Type{<:Reactant.F8E4M3FN}; context::Context=context())
     return Type(API.mlirFloat8E4M3FNTypeGet(context))
 end
 
@@ -214,7 +214,7 @@ end
 
 Creates a f8e4m3b11fnuz type in the given context. The type is owned by the context.
 """
-function Type(::Core.Type{Reactant.F8E4M3B11FNUZ}; context::Context=context())
+function Type(::Core.Type{<:Reactant.F8E4M3B11FNUZ}; context::Context=context())
     return Type(API.mlirFloat8E4M3B11FNUZTypeGet(context))
 end
 
@@ -223,7 +223,7 @@ end
 
 Creates a f8e5m2fnuz type in the given context. The type is owned by the context.
 """
-function Type(::Core.Type{Reactant.F8E5M2FNUZ}; context::Context=context())
+function Type(::Core.Type{<:Reactant.F8E5M2FNUZ}; context::Context=context())
     return Type(API.mlirFloat8E5M2FNUZTypeGet(context))
 end
 
@@ -232,7 +232,7 @@ end
 
 Creates a f8e4m3fnuz type in the given context. The type is owned by the context.
 """
-function Type(::Core.Type{Reactant.F8E4M3FNUZ}; context::Context=context())
+function Type(::Core.Type{<:Reactant.F8E4M3FNUZ}; context::Context=context())
     return Type(API.mlirFloat8E4M3FNTypeGet(context))
 end