support wide ints in tape

src/compiler.jl

@@ -6037,6 +6037,15 @@ const TapeTypes = Dict{String, DataType}()
 base_type(T::UnionAll) = base_type(T.body)
 base_type(T::DataType) = T
 
+const WideIntWidths = [256, 512, 1024, 2048]
+
+let
+    for n ∈ WideIntWidths
+        let T = Symbol(:UInt,n)
+            eval(quote primitive type $T  <: Unsigned $n end end)
+        end
+    end
+end
 # return result and if contains any
 function to_tape_type(Type::LLVM.API.LLVMTypeRef)::Tuple{DataType,Bool}
     tkind = LLVM.API.LLVMGetTypeKind(Type)
@@ -6105,6 +6114,14 @@ function to_tape_type(Type::LLVM.API.LLVMTypeRef)::Tuple{DataType,Bool}
             return UInt64, false
         elseif N == 128
             return UInt128, false
+        elseif N == 256
+            return UInt256, false
+        elseif N == 512
+            return UInt512, false
+        elseif N == 1024
+            return UInt1024, false
+        elseif N == 2048
+            return UInt2048, false
         else
             error("Can't construct tape type for integer of width $N")
         end

test/Project.toml

@@ -5,6 +5,7 @@ Enzyme_jll = "7cc45869-7501-5eee-bdea-0790c847d4ef"
 FiniteDifferences = "26cc04aa-876d-5657-8c51-4c34ba976000"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 GPUCompiler = "61eb1bfa-7361-4325-ad38-22787b887f55"
+InlineStrings = "842dd82b-1e85-43dc-bf29-5d0ee9dffc48"
 LLVM = "929cbde3-209d-540e-8aea-75f648917ca0"
 LLVM_jll = "86de99a1-58d6-5da7-8064-bd56ce2e322c"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

test/runtests.jl

@@ -16,6 +16,7 @@ using ForwardDiff
 using Aqua
 using Statistics
 using LinearAlgebra
+using InlineStrings
 
 using Enzyme_jll
 @info "Testing against" Enzyme_jll.libEnzyme
@@ -2278,6 +2279,32 @@ end
     @test ad_eta[1] ≈ 0.0
 end
 
+@testset "Tape Width" begin
+    struct Roo
+        x::Float64
+        bar::String63
+    end
+
+    struct Moo
+        x::Float64
+        bar::String63
+    end
+
+    function g(f)
+        return f.x*5.0
+    end
+
+    res = autodiff(Reverse, g, Active, Active(Roo(3.0, "a")))[1][1]
+
+    @test res.x == 5.0
+
+    if VERSION > v"1.10-"
+        res = autodiff(Reverse, g, Active, Active(Moo(3.0, "a")))[1][1]
+
+        @test res.x == 5.0
+    end
+end
+
 @testset "Type preservation" begin
     # Float16 fails due to #870
     for T in (Float64, Float32, #=Float16=#)