[SR-13210] Forward mode differentiation SIL verification crash

[swift-ci]

Previous ID	SR-13210
Radar	None
Original Reporter	aefr (JIRA User)
Type	Bug

Additional Detail from JIRA

Votes	0
Component/s
Labels	Bug
Assignee	None
Priority	Medium

md5: cb81b52c0a39a78b5112773d78acdf10

Issue Description:

Verification crashes on the following test:

Test in forward_mode.swift:

ForwardModeTests.test("Generics") {
  let a = SIMD3<Double>(1, 2, 3)
  let g = SIMD3<Double>(1, 1, 1)

  func testInit<Scalar, SIMDType: SIMD>(x: Scalar) -> SIMDType
    where SIMDType.Scalar == Scalar,
          SIMDType : Differentiable,
          Scalar : BinaryFloatingPoint & Differentiable,
          SIMDType.TangentVector == SIMDType,
          Scalar.TangentVector == Scalar {
    return SIMDType.init(repeating: x)
  }
  func simd3Init(x: Double) -> SIMD3<Double> { testInit(x: x) }
  let (val1, df1) = valueWithDifferential(at: 10, in: simd3Init)
  expectEqual(SIMD3<Double>(10, 10, 10), val1)
  expectEqual(SIMD3<Double>(5, 5, 5), df1(5))

  // SIMDType + SIMDType
  func testAddition<Scalar, SIMDType: SIMD>(lhs: SIMDType, rhs: SIMDType)
    -> SIMDType
    where SIMDType.Scalar == Scalar,
          SIMDType : Differentiable,
          SIMDType.TangentVector : SIMD,
          Scalar : BinaryFloatingPoint,
          SIMDType.TangentVector.Scalar : BinaryFloatingPoint {
    return lhs + rhs
  }
  func simd3Add(lhs: SIMD3<Double>, rhs: SIMD3<Double>) -> SIMD3<Double> {
    return testAddition(lhs: lhs, rhs: rhs)
  }
  let (val2, df2) = valueWithDifferential(at: a, a, in: simd3Add)
  expectEqual(SIMD3<Double>(2, 4, 6), val2)
  expectEqual(g + a, df2(g, a))

  // Scalar - SIMDType
  func testSubtraction<Scalar, SIMDType: SIMD>(lhs: Scalar, rhs: SIMDType)
    -> SIMDType
    where SIMDType.Scalar == Scalar,
          SIMDType : Differentiable,
          Scalar : BinaryFloatingPoint & Differentiable,
          SIMDType.TangentVector == SIMDType,
          Scalar.TangentVector == Scalar {
    return lhs - rhs
  }
  func simd3Subtract(lhs: Double, rhs: SIMD3<Double>) -> SIMD3<Double> {
    return testSubtraction(lhs: lhs, rhs: rhs)
  }
  let (val3, df3) = valueWithDifferential(at: 5, a, in: simd3Subtract)
  expectEqual(SIMD3<Double>(4, 3, 2), val3)
  expectEqual(2 - g, df3(2, g))

  // SIMDType * Scalar
  func testMultipication<Scalar, SIMDType: SIMD>(lhs: SIMDType, rhs: Scalar)
    -> SIMDType
    where SIMDType.Scalar == Scalar,
      SIMDType : Differentiable,
      Scalar : BinaryFloatingPoint & Differentiable,
      SIMDType.TangentVector == SIMDType,
      Scalar.TangentVector == Scalar {
    return lhs * rhs
  }
  func simd3Multiply(lhs: SIMD3<Double>, rhs: Double) -> SIMD3<Double> {
    return testMultipication(lhs: lhs, rhs: rhs)
  }
  let (val4, df4) = valueWithDifferential(at: a, 5, in: simd3Multiply)
  expectEqual(SIMD3<Double>(5, 10, 15), val4)
  expectEqual(a * 3 + g * 5 , df4(g, 3))
}

Running the test:

llvm-project/llvm/utils/lit/lit.py -vvv build/Ninja-ReleaseAssert/swift-linux-x86_64/test-linux-x86_64/AutoDiff/ --filter forward_mode

Relevant part of the output:

SIL verification failed: Found mutating or consuming use of an in_guaranteed parameter?!: !ImmutableAddressUseVerifier().isMutatingOrConsuming(fArg)
Verifying argument:
-> %1 = argument of bb0 : $*τ_0_0                // user: %3
     %3 = apply %2(%0, %1) : $@callee_guaranteed (@in τ_0_0) -> @out τ_0_1
In function:
// thunk for @escaping @callee_guaranteed (@in A) -> (@out B)
sil shared [serialized] [reabstraction_thunk] @$sxq_Iegir_xq_Iegnr_SBRz16_Differentiation14DifferentiableRz13TangentVectorAaBPQzRszs4SIMDR_AaBR_AcDQy_Rs_6Scalars11SIMDStoragePQy_AERSr0_lTR : $@convention(thin) <τ_0_0, τ_0_1 where τ_0_0 : BinaryFloatingPoint, τ_0_0 : Differentiable, τ_0_0 == τ_0_0.TangentVector, τ_0_1 : SIMD, τ_0_1 : Differentiable, τ_0_1 == τ_0_1.TangentVector, τ_0_0.TangentVector == τ_0_1.Scalar> (@in_guaranteed τ_0_0, @guaranteed @callee_guaranteed (@in τ_0_0) -> @out τ_0_1) -> @out τ_0_1 {
// %0                                             // user: %3
// %1                                             // user: %3
// %2                                             // user: %3
bb0(%0 : $*τ_0_1, %1 : $*τ_0_0, %2 : $@callee_guaranteed (@in τ_0_0) -> @out τ_0_1):
  %3 = apply %2(%0, %1) : $@callee_guaranteed (@in τ_0_0) -> @out τ_0_1
  %4 = tuple ()                                   // user: %5
  return %4 : $()                                 // id: %5
} // end sil function '$sxq_Iegir_xq_Iegnr_SBRz16_Differentiation14DifferentiableRz13TangentVectorAaBPQzRszs4SIMDR_AaBR_AcDQy_Rs_6Scalars11SIMDStoragePQy_AERSr0_lTR'