Merge pull request #27157 from DougGregor/simd-as-additivearithmetic

Author: swift-ci

stdlib/public/core/SIMDVector.swift

@@ -1407,3 +1407,16 @@ where T: SIMD, T.Scalar: FloatingPoint {
   }
   return result
 }
+
+// Break the ambiguity between AdditiveArithmetic and SIMD for += and -=
+extension SIMD where Self: AdditiveArithmetic, Self.Scalar: FloatingPoint {
+  @_alwaysEmitIntoClient
+  public static func +=(lhs: inout Self, rhs: Self) {
+    lhs = lhs + rhs
+  }
+
+  @_alwaysEmitIntoClient
+  public static func -=(lhs: inout Self, rhs: Self) {
+    lhs = lhs - rhs
+  }
+}

test/stdlib/SIMD_as_AdditiveArithmetic.swift

@@ -0,0 +1,5 @@
+// RUN: %target-typecheck-verify-swift
+extension SIMD2: AdditiveArithmetic where Scalar: FloatingPoint { }
+extension SIMD3: AdditiveArithmetic where Scalar: FloatingPoint { }
+extension SIMD4: AdditiveArithmetic where Scalar: FloatingPoint { }
+extension SIMD8: AdditiveArithmetic where Scalar: FloatingPoint { }