Add tests

Author: asl

test/AutoDiff/compiler_crashers_fixed/issue-59135-nested-function-diff-wittness-capture-promotion.swift

@@ -0,0 +1,33 @@
+// RUN: %target-swift-emit-sil -Xllvm -debug-only=differentiation -o /dev/null 2>&1 %s | %FileCheck %s
+
+// The differentiability witness for y in s(h:) will be generated by silgen. However, later the capture
+// promotion pass would specialize it since it only captures an integer and therefore does not need to
+// box the capture. Ensure we create differentiability witness for specialized function. In addition to
+// this, since the original function is not used anymore, the body of it is removed (with only unreachable
+// terminator inside). Remove original differentiability witness as it would lead to non-differentiable
+// diagnostics further on.
+
+// CHECK-LABEL: differentiability witness for specialized y #1 (_:) in s(h:)
+// CHECK: sil_differentiability_witness private [reverse] [parameters 0] [results 0] @$s4null1s1hAA1BVAE_tF1yL_yAA1WVAHFTf2ni_n : $@convention(thin) (@guaranteed W, Int) -> @owned W {
+// CHECK-NOT: sil_differentiability_witness private [reverse] [parameters 0] [results 0] @$s4null1s1hAA1BVAE_tF1yL_yAA1WVAHF : $@convention(thin) (@guaranteed W, @guaranteed { var Int }) -> @owned W {
+
+import _Differentiation
+struct B: Differentiable{}
+struct X { var j = [Float]()}
+struct W: Differentiable {
+    @noDerivative var z: X
+    var h: B
+}
+func o<T, R>(_ x: T, _ f: @differentiable(reverse) (T) -> R) -> R {f(x)}
+func m<T, R>(_ f: @escaping @differentiable(reverse) (T) -> R) -> @differentiable(reverse) (T) -> R {{ x in o(x, f) }}
+@differentiable(reverse)
+ func s(h: B) -> B {
+    var (_, e) = (0,0)
+    @differentiable(reverse)
+    func y(_ i: W) -> W {
+        let _ = e;
+        return i
+    }
+    let w = m(y)
+    return B()
+}

test/AutoDiff/compiler_crashers_fixed/issue-59135-usableFromInline-VJP.swift

@@ -0,0 +1,38 @@
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-emit-sil -Xllvm -debug-only=differentiation -emit-module -module-name M -emit-module-path %t/M.swiftmodule 2>&1 %s | %FileCheck %s
+
+// The original function Tensor.subscriptIndexPath() is not marked as @differentiable. As a result, no explicit differentiable witness is generated for it.
+// However, the witness is generated as a side effect of providing a derivative via  @derivative(of: subscriptIndexPath) on _vjpSubscriptIndexPath.
+// Since _vjpSubscriptIndexPath is not emitted when -emit-module is used, we need to ensure we still generate a wittness.
+
+import _Differentiation
+
+// CHECK-LABEL: differentiability witness for Tensor.subscriptIndexPath()
+// CHECK: sil_differentiability_witness [serialized] [reverse] [parameters 0] [results 0] @$s1M6TensorV18subscriptIndexPathACyF : $@convention(method) (Tensor) -> Tensor {
+// CHECK:  vjp: @$s1M6TensorV18subscriptIndexPathACyFTJrSpSr : $@convention(method) (Tensor) -> (Tensor, @owned @callee_guaranteed (Tensor) -> Tensor)
+
+// CHECK-LABEL: reverse-mode derivative of Tensor.subscriptIndexPath()
+// CHECK: sil [thunk] [always_inline] [ossa] @$s1M6TensorV18subscriptIndexPathACyFTJrSpSr : $@convention(method) (Tensor) -> (Tensor, @owned @callee_guaranteed (Tensor) -> Tensor) {
+// CHECK: function_ref Tensor._vjpSubscriptIndexPath()
+// CHECK: function_ref @$s1M6TensorV22_vjpSubscriptIndexPathAC5value_A2Cc8pullbacktyF : $@convention(method) (Tensor) -> (Tensor, @owned @callee_guaranteed (Tensor) -> Tensor)
+
+public struct Tensor: Differentiable & AdditiveArithmetic {
+  @inlinable
+  func subscriptIndexPath() -> Tensor {
+    fatalError()
+  }
+
+  @inlinable
+  @differentiable(reverse, wrt: self)
+  func subscriptRanges() -> Tensor {
+    subscriptIndexPath()
+  }
+  
+  @usableFromInline
+  @derivative(of: subscriptIndexPath)
+  func _vjpSubscriptIndexPath() -> (
+    value: Tensor, pullback: (Tensor) -> Tensor
+  ) {
+    fatalError()
+  }
+}