Files
swift-mirror/test/AutoDiff/SILOptimizer/differentiation_sil.swift
Richard Wei e494df2ee6 [AutoDiff] Add differentiability kind to differentiability witnesses and mangle them.
Differentiability witnesses are now keyed by the original function name, the differentiability kind, and the autodiff config.

Updated SIL syntax:
```
differentiability-kind ::= 'forward' | 'reverse' | 'normal' | 'linear'
sil-differentiability-witness ::=
    'sil_differentiability_witness'
    sil-linkage?
    '[' differentiability-kind ']'
    '[' 'parameters' sil-differentiability-witness-function-index-list ']'
    '[' 'results' sil-differentiability-witness-function-index-list ']'
    generic-parameter-clause?
    sil-function-name ':' sil-type
    sil-differentiability-witness-body?
sil-instruction ::=
    'differentiability_witness_function'
    '[' sil-differentiability-witness-function-kind ']'
    '[' differentiability-kind ']'
    '[' 'parameters' sil-differentiability-witness-function-index-list ']'
    '[' 'results' sil-differentiability-witness-function-index-list ']'
    generic-parameter-clause?
    sil-function-name ':' sil-type
```
```console
sil_differentiability_witness [reverse] [parameters 0 1] [results 0] <T where T: Differentiable> @foo : <T> $(T) -> T
differentiability_witness_function [vjp] [reverse] [parameters 0] [results 0] <T where T: Differentiable> @foo : $(T) -> T
```

New mangling:
```swift
  global ::= global generic-signature? 'WJ' DIFFERENTIABILITY-KIND INDEX-SUBSET 'p' INDEX-SUBSET 'r' // differentiability witness
```
```console
$s13test_mangling3fooyS2f_S2ftFWJrSpSr ---> reverse differentiability witness for test_mangling.foo(Swift.Float, Swift.Float, Swift.Float) -> Swift.Float with respect to parameters {0} and results {0}
```

Resolves rdar://74380324.
2021-02-17 18:27:42 -05:00

44 lines
2.7 KiB
Swift

// RUN: %target-swift-frontend -emit-silgen %s | %FileCheck %s --check-prefix=CHECK-SILGEN
// RUN: %target-swift-frontend -enable-experimental-forward-mode-differentiation -emit-sil %s | %FileCheck %s --check-prefix=CHECK-SIL
// Simple differentiation transform test: check SIL before and after the transform.
import _Differentiation
@_silgen_name("basic")
@differentiable(reverse)
func basic(_ x: Float) -> Float { x }
// Test differentiability witnesses.
// CHECK-SILGEN-LABEL: sil_differentiability_witness hidden [reverse] [parameters 0] [results 0] @basic : $@convention(thin) (Float) -> Float {
// CHECK-SILGEN-NEXT: }
// CHECK-SIL-LABEL: sil_differentiability_witness hidden [reverse] [parameters 0] [results 0] @basic : $@convention(thin) (Float) -> Float {
// CHECK-SIL-NEXT: jvp: @basicTJfSpSr : $@convention(thin) (Float) -> (Float, @owned @callee_guaranteed (Float) -> Float)
// CHECK-SIL-NEXT: vjp: @basicTJrSpSr : $@convention(thin) (Float) -> (Float, @owned @callee_guaranteed (Float) -> Float)
// CHECK-SIL-NEXT: }
// Test `differentiable_function` instructions.
@_silgen_name("test_differentiable_function")
func testDifferentiableFunction() {
let _: @differentiable(reverse) (Float) -> Float = basic
}
// CHECK-SILGEN-LABEL: sil hidden [ossa] @test_differentiable_function : $@convention(thin) () -> () {
// CHECK-SILGEN: [[ORIG_FN_REF:%.*]] = function_ref @basic : $@convention(thin) (Float) -> Float
// CHECK-SILGEN: [[ORIG_FN:%.*]] = thin_to_thick_function [[ORIG_FN_REF]] : $@convention(thin) (Float) -> Float to $@callee_guaranteed (Float) -> Float
// CHECK-SILGEN: [[DIFF_FN:%.*]] = differentiable_function [parameters 0] [results 0] [[ORIG_FN]] : $@callee_guaranteed (Float) -> Float
// CHECK-SILGEN: }
// CHECK-SIL-LABEL: sil hidden @test_differentiable_function : $@convention(thin) () -> () {
// CHECK-SIL: [[ORIG_FN_REF:%.*]] = function_ref @basic : $@convention(thin) (Float) -> Float
// CHECK-SIL: [[ORIG_FN:%.*]] = thin_to_thick_function [[ORIG_FN_REF]]
// CHECK-SIL: [[JVP_FN_REF:%.*]] = differentiability_witness_function [jvp] [reverse] [parameters 0] [results 0] @basic
// CHECK-SIL: [[JVP_FN:%.*]] = thin_to_thick_function [[JVP_FN_REF]]
// CHECK-SIL: [[VJP_FN_REF:%.*]] = differentiability_witness_function [vjp] [reverse] [parameters 0] [results 0] @basic
// CHECK-SIL: [[VJP_FN:%.*]] = thin_to_thick_function [[VJP_FN_REF]]
// CHECK-SIL: [[DIFF_FN:%.*]] = differentiable_function [parameters 0] [results 0] [[ORIG_FN]] : $@callee_guaranteed (Float) -> Float with_derivative {[[JVP_FN]] : $@callee_guaranteed (Float) -> (Float, @owned @callee_guaranteed (Float) -> Float), [[VJP_FN]] : $@callee_guaranteed (Float) -> (Float, @owned @callee_guaranteed (Float) -> Float)}
// CHECK-SIL: }