| // RUN: %empty-directory(%t) |
| // RUN: %target-swift-frontend -emit-silgen %s -o %t/roundtrip.sil |
| // RUN: %target-swift-frontend -emit-sil %t/roundtrip.sil |
| |
| // TF-656: Verify that `AutoDiffIndexSubset` for SIL `[differentiable]` |
| // attribute is set correctly. |
| |
| // Otherwise, an assertion is triggered during the differentiation transform: |
| // Assertion failed: (newCapacity >= capacity), function extendingCapacity |
| // ... ADContext::promoteToDifferentiableFunction |
| |
| // NOTE: We cannot differentiate external functions in roundtrip SIL tests. |
| // Reason: When we print then parse the SIL we lose the information that the |
| // external function is associated with an AST decl. So the differentiation |
| // pass can't see the AST differentiable attrs, and the differentiation pass |
| // thinks that we're trying to differentiate an external function without |
| // explicit AST differentiable attrs. |
| // TODO(TF-988): This can probably be fixed. |
| |
| @differentiable(wrt: x) |
| func TF_656(_ x: Float, _ y: Float) -> Float { |
| // FIXME(TF-988): Cannot differentiate external functions. |
| // return x + y |
| return 0 |
| } |
| _ = gradient(at: 1, in: { x in TF_656(x, 2) }) |
