No need for custom twist rule (#483)

Author: kshyatt

ext/TensorKitEnzymeExt/indexmanipulations.jl

@@ -116,33 +116,6 @@ function EnzymeRules.reverse(
     return nothing, nothing, nothing, nothing, Δαr, Δβr, map(Returns(nothing), ba)...
 end
 
-function EnzymeRules.augmented_primal(
-        config::EnzymeRules.RevConfigWidth{1},
-        func::Const{typeof(twist!)},
-        ::Type{RT},
-        t::Annotation{<:AbstractTensorMap},
-        inds::Const;
-        inv::Bool = false
-    ) where {RT}
-    twist!(t.val, inds.val; inv)
-    primal = EnzymeRules.needs_primal(config) ? t.val : nothing
-    shadow = EnzymeRules.needs_shadow(config) ? t.dval : nothing
-    return EnzymeRules.AugmentedReturn(primal, shadow, nothing)
-end
-
-function EnzymeRules.reverse(
-        config::EnzymeRules.RevConfigWidth{1},
-        func::Const{typeof(twist!)},
-        ::Type{RT},
-        cache,
-        t::Annotation{<:AbstractTensorMap},
-        inds::Const;
-        inv::Bool = false
-    ) where {RT}
-    !isa(t, Const) && twist!(t.dval, inds.val; inv = !inv)
-    return (nothing, nothing)
-end
-
 function EnzymeRules.augmented_primal(
         config::EnzymeRules.RevConfigWidth{1},
         func::Const{typeof(flip)},

test/enzyme-indexmanipulations-flip-twist/twist.jl

@@ -20,6 +20,10 @@ if !Sys.iswindows() && VERSION > v"1.11.0-rc"
                 EnzymeTestUtils.test_reverse(twist!, TA, (copy(A), TA), ([1, 3], Const); atol, rtol, fkwargs = (inv = true,))
                 EnzymeTestUtils.test_reverse(twist!, TA, (copy(A), TA), (1, Const); atol, rtol)
                 EnzymeTestUtils.test_reverse(twist!, TA, (copy(A), TA), ([1, 3], Const); atol, rtol)
+                EnzymeTestUtils.test_forward(twist!, TA, (copy(A), TA), (1, Const); atol, rtol, fkwargs = (inv = false,))
+                EnzymeTestUtils.test_forward(twist!, TA, (copy(A), TA), ([1, 3], Const); atol, rtol, fkwargs = (inv = true,))
+                EnzymeTestUtils.test_forward(twist!, TA, (copy(A), TA), (1, Const); atol, rtol)
+                EnzymeTestUtils.test_forward(twist!, TA, (copy(A), TA), ([1, 3], Const); atol, rtol)
             end
         end
     end