Fix reverse mode closure issues (#1533)

* Fix custom reverse on closure

* fix closure

Author: wsmoses

src/rules/customrules.jl

@@ -687,7 +687,8 @@ function enzyme_custom_common_rev(forward::Bool, B, orig::LLVM.CallInst, gutils,
             end
         end
     end
-    push!(function_attributes(llvmf), EnumAttribute("alwaysinline", 0))
+
+    # push!(function_attributes(llvmf), EnumAttribute("alwaysinline", 0))
 
     needsTape = !isghostty(TapeT) && !Core.Compiler.isconstType(TapeT)
 
@@ -711,22 +712,37 @@ function enzyme_custom_common_rev(forward::Bool, B, orig::LLVM.CallInst, gutils,
 
     swiftself = any(any(map(k->kind(k)==kind(EnumAttribute("swiftself")), collect(parameter_attributes(llvmf, i)))) for i in 1:length(collect(parameters(llvmf))))
 
-    _, sret, returnRoots = get_return_info(enzyme_custom_extract_mi(llvmf)[2])
+    miRT = enzyme_custom_extract_mi(llvmf)[2]
+    _, sret, returnRoots = get_return_info(miRT)
 
     if !forward
+        funcTy = rev_TT.parameters[isKWCall ? 4 : 2] 
         if needsTape
             @assert tape != C_NULL
-            tape_idx = 1+(kwtup!==nothing && !isghostty(kwtup))+(isKWCall && !isghostty(rev_TT.parameters[4]))
-            innerTy = value_type(parameters(llvmf)[tape_idx+(sret !== nothing)+(RT <: Active)])
+            tape_idx = 1+(kwtup!==nothing && !isghostty(kwtup))+(isKWCall && !isghostty(rev_TT.parameters[4])) + !isghostty(funcTy)
+            trueidx = tape_idx+(sret !== nothing)+(returnRoots !== nothing)+swiftself+(RT <: Active)
+            innerTy = value_type(parameters(llvmf)[trueidx])
             if innerTy != value_type(tape)
-                if isabstracttype(TapeT)
+                if isabstracttype(TapeT) || TapeT == Tuple || TapeT.layout == C_NULL
                     msg = sprint() do io
                         println(io, "Enzyme : mismatch between innerTy $innerTy and tape type $(value_type(tape))")
                         println(io, "tape_idx=", tape_idx)
+                        println(io, "true_idx=", trueidx)
+                        println(io, "isKWCall=", isKWCall)
+                        println(io, "kwtup=", kwtup)
+                        println(io, "funcTy=", funcTy)
+                        println(io, "isghostty(funcTy)=", isghostty(funcTy))
+                        println(io, "miRT=", miRT)
                         println(io, "sret=", sret)
+                        println(io, "returnRoots=", returnRoots)
+                        println(io, "swiftself=", swiftself)
                         println(io, "RT=", RT)
                         println(io, "tape=", tape)
-                        println(io, "llvmf=", string(llvmf))
+                        println(io, "llvmf=", string(LLVM.function_type(llvmf)))
+                        println(io, "TapeT=", TapeT)
+                        println(io, "mi=", mi)
+                        println(io, "ami=", ami)
+                        println(io, "rev_TT =", rev_TT)
                     end
                     throw(AssertionError(msg))
                 end
@@ -749,7 +765,7 @@ function enzyme_custom_common_rev(forward::Bool, B, orig::LLVM.CallInst, gutils,
                 val = LLVM.Value(API.EnzymeGradientUtilsDiffe(gutils, orig, B))
             else
                 llety = convert(LLVMType, eltype(RT))
-                ptr_val = invert_pointer(gutils, operands(orig)[1], B)
+                ptr_val = invert_pointer(gutils, operands(orig)[1 + !isghostty(funcTy)], B)
                 val = UndefValue(LLVM.LLVMType(API.EnzymeGetShadowType(width, llety)))
                 for idx in 1:width
                     ev = (width == 1) ? ptr_val : extract_value!(B, ptr_val, idx-1)
@@ -769,8 +785,7 @@ function enzyme_custom_common_rev(forward::Bool, B, orig::LLVM.CallInst, gutils,
             if any_jltypes(llty)
                 emit_writebarrier!(B, get_julia_inner_types(B, al0, val))
             end
-
-            insert!(args, 1+(kwtup!==nothing && !isghostty(kwtup))+(isKWCall && !isghostty(rev_TT.parameters[4])), al)
+            insert!(args, 1+(!isghostty(funcTy))+(kwtup!==nothing && !isghostty(kwtup))+(isKWCall && !isghostty(rev_TT.parameters[4])), al)
         end
     end
 

test/rrules.jl

@@ -305,4 +305,44 @@ end
     @test dU[1] ≈ 7 * ( 3.0 + 4.0im )
 end
 end
+
+
+struct Closure
+    v::Vector{Float64}
+end
+
+function (cl::Closure)(x)
+    val = cl.v[1] * x
+    cl.v[1] = 0.0
+    return val
+end
+
+
+function EnzymeRules.augmented_primal(config::ConfigWidth{1}, func::Const{Closure},
+    ::Type{<:Active}, args::Vararg{Active,N}) where {N}
+    vec = copy(func.val.v)
+    pval = func.val(args[1].val)
+    primal = if EnzymeRules.needs_primal(config)
+        pval
+    else
+        nothing
+    end
+    return AugmentedReturn(primal, nothing, vec)
+end
+
+function EnzymeRules.reverse(config::ConfigWidth{1}, func::Const{Closure},
+    dret::Active, tape, args::Vararg{Active,N}) where {N}
+    dargs = ntuple(Val(N)) do i
+        7 * args[1].val * dret.val + tape[1] * 1000
+    end
+    return dargs
+end
+
+@testset "Closure rule" begin
+    cl = Closure([3.14])
+    res = autodiff(Reverse, cl, Active, Active(2.7))[1][1]
+    @test res ≈ 7 * 2.7 + 3.14 * 1000
+    @test cl.v[1] ≈ 0.0
+end
+
 end # ReverseRules