From ac8a9fb3f9c1a07cc96defebc77baec17ea8d9cd Mon Sep 17 00:00:00 2001
From: Billy Moses <wmoses@google.com>
Date: Wed, 8 Jul 2026 11:34:55 -0500
Subject: [PATCH] Fix idx/rt getfield

---
 src/rules/typeunstablerules.jl | 16 ++++++++--------
 test/typeunstable.jl           | 22 ++++++++++++++++++++++
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/src/rules/typeunstablerules.jl b/src/rules/typeunstablerules.jl
index bd5a17d3f0..7283fc455a 100644
--- a/src/rules/typeunstablerules.jl
+++ b/src/rules/typeunstablerules.jl
@@ -1226,8 +1226,8 @@ function rt_jl_getfield_aug(
     dptr::T,
     ::Type{Val{symname}},
     ::Val{isconst},
-    dptrs::Vararg{T2,Nargs},
-) where {NT,T,T2,Nargs,symname,isconst}
+    dptrs::Vararg{T,Nargs},
+) where {NT,T,Nargs,symname,isconst}
     res = if dptr isa Base.RefValue
         Base.getfield(dptr[], symname)
     else
@@ -1274,8 +1274,8 @@ function idx_jl_getfield_aug(
     dptr::T,
     ::Type{Val{symname}},
     ::Val{isconst},
-    dptrs::Vararg{T2,Nargs},
-) where {NT,T,T2,Nargs,symname,isconst}
+    dptrs::Vararg{T,Nargs},
+) where {NT,T,Nargs,symname,isconst}
     res = if dptr isa Base.RefValue
         Base.getfield(dptr[], symname + 1)
     else
@@ -1343,8 +1343,8 @@ function rt_jl_getfield_rev(
     dret,
     ::Type{Val{symname}},
     ::Val{isconst},
-    dptrs::Vararg{T2,Nargs},
-) where {T,T2,Nargs,symname,isconst}
+    dptrs::Vararg{T,Nargs},
+) where {T,Nargs,symname,isconst}
     cur = if dptr isa Base.RefValue
         getfield(dptr[], symname)
     else
@@ -1425,8 +1425,8 @@ function idx_jl_getfield_rev(
     dret,
     ::Type{Val{symname}},
     ::Val{isconst},
-    dptrs::Vararg{T2,Nargs},
-) where {T,T2,Nargs,symname,isconst}
+    dptrs::Vararg{T,Nargs},
+) where {T,Nargs,symname,isconst}
     cur = if dptr isa Base.RefValue
         Base.getfield(dptr[], symname + 1)
     else
diff --git a/test/typeunstable.jl b/test/typeunstable.jl
index dd45b76b9c..b1a69d08a1 100644
--- a/test/typeunstable.jl
+++ b/test/typeunstable.jl
@@ -263,4 +263,26 @@ end
     idx = Base.inferencebarrier(2)
     res = Enzyme.autodiff(set_runtime_activity(Forward), getfield_unstable_fn, Duplicated([2.0, 3.0], [1.0, 0.0]), Const(idx))
     @test res[1] ≈ 3.0
+end
+
+struct MiniProblem3280{U, P, K}
+    u0::U
+    tspan::Tuple{Float64, Float64}
+    p::P
+    kwargs::K
+end
+
+function loss_3280(p)
+    prob = MiniProblem3280([1.0], (0.0, 1.0), p, pairs((;)))
+    active_field = Enzyme.Compiler.idx_jl_getfield_aug(
+        Val(NamedTuple{(1,)}), prob, Val{2}, Val(false))
+    return sum(abs2, active_field)
+end
+
+@testset "idx_jl_getfield_aug calling convention (Issue 3280 reproducer)" begin
+    p = [0.5]
+    dp = zero(p)
+    Enzyme.autodiff(set_runtime_activity(Reverse), Enzyme.Const(loss_3280), Enzyme.Active,
+        Enzyme.Duplicated(p, dp))
+    @test dp ≈ [1.0]
 end
\ No newline at end of file