| // RUN: %target-swift-emit-sil -enable-experimental-forward-mode-differentiation %s -verify |
| // REQUIRES: asserts |
| |
| // TF-984: Differential generation crash due to unset tangent buffer. |
| |
| struct Mut: Differentiable {} |
| extension Mut { |
| mutating func mutatingMethodWrtMultipleResults(_ x: Mut) -> Mut { |
| return x |
| } |
| } |
| |
| @differentiable(wrt: x) |
| func activeInoutArgMutatingMethodVar(_ nonactive: inout Mut, _ x: Mut) { |
| _ = nonactive.mutatingMethodWrtMultipleResults(x) |
| } |
| |
| // [AD] Original bb0: To differentiate or not to differentiate? |
| // [ ] debug_value_addr %0 : $*Mut, var, name "nonactive", argno 1 // id: %2 |
| // [ ] debug_value %1 : $Mut, let, name "x", argno 2 // id: %3 |
| // [∂] %4 = alloc_stack $Mut, var, name "result" // users: %18, %6, %8, %12, %15 |
| // [ ] %5 = begin_access [read] [static] %0 : $*Mut // users: %7, %6 |
| // [∂] copy_addr %5 to [initialization] %4 : $*Mut // id: %6 |
| // ... |
| // [AD] JVPEmitter visited: |
| // [ORIG] copy_addr %5 to [initialization] %4 : $*Mut // id: %6 |
| // Assertion failed: (!insertion.second && "tangent buffer should already exist"), function getTangentBuffer, file swift/lib/SILOptimizer/Mandatory/Differentiation.cpp, line 4528. |
| |
| // `copy_addr %5 to [initialization] %4` is visited but `%5 = begin_access` is |
| // not. `%5` does not have a set tangent buffer. |
