fix

src/compiler.jl

@@ -4740,7 +4740,8 @@ function enzyme_custom_common_rev(forward::Bool, B, orig::LLVM.CallInst, gutils,
 
         idx = 0
         dl = string(LLVM.datalayout(LLVM.parent(LLVM.parent(LLVM.parent(orig)))))
-        for (v, Ty) in zip(actives, Tys)
+        Tys2 = (eltype(A) for A in activity[2+isKWCall:end] if A <: Active)
+        for (v, Ty) in zip(actives, Tys2)
             TT = typetree(Ty, ctx, dl)
             Typ = C_NULL
             ext = extract_value!(B, res, idx)

src/internal_rules.jl

@@ -429,6 +429,7 @@ function EnzymeRules.reverse(config, func::Const{typeof(\)}, ::Type{RT}, cache,
     return (nothing,nothing)
 end
 
+@static if VERSION >= v"1.7-"
 # Force a rule around hvcat_fill as it is type unstable if the tuple is not of the same type (e.g., int, float, int, float)
 function EnzymeRules.augmented_primal(config, func::Const{typeof(Base.hvcat_fill!)}, ::Type{RT}, out::Annotation{AT}, inp::Annotation{BT}) where {RT, AT <: Array, BT <: Tuple}
     primal = if EnzymeRules.needs_primal(config)
@@ -442,15 +443,6 @@ function EnzymeRules.augmented_primal(config, func::Const{typeof(Base.hvcat_fill
         nothing
     end
     func.val(out.val, inp.val)
-
-    if EnzymeRules.width(config) == 1
-        out.dval .= 0
-    else
-        for i in 1:EnzymeRules.width(config)
-            out.dval[i] .= 0
-        end
-    end
-
     return EnzymeRules.AugmentedReturn(primal, shadow, nothing)
 end
 
@@ -486,3 +478,4 @@ function EnzymeRules.reverse(config, func::Const{typeof(Base.hvcat_fill!)}, ::Ty
     end
     return (nothing, nothing)
 end
+end

test/runtests.jl

@@ -2544,11 +2544,12 @@ end
     @test dA ≈ (-z * transpose(y))
 end
 
+@static if VERSION >= v"1.7-"
 @testset "hvcat_fill" begin
     ar = Matrix{Float64}(undef, 2, 3)
     dar = [1.0 2.0 3.0; 4.0 5.0 6.0]
 
-    res = Enzyme.autodiff(Reverse, Base.hvcat_fill!, Const, Duplicated(ar, dar), Active((1, 2.2, 3, 4.4, 5, 6.6)))
+    res = first(Enzyme.autodiff(Reverse, Base.hvcat_fill!, Const, Duplicated(ar, dar), Active((1, 2.2, 3, 4.4, 5, 6.6))))
 
     @test res[2][1] == 0
     @test res[2][2] ≈ 2.0
@@ -2557,4 +2558,5 @@ end
     @test res[2][5] ≈ 0
     @test res[2][6] ≈ 6.0
 end
+end