RequirementMachine: Add a performance/diagnostics test case

Author: slavapestov

test/Generics/rdar51908331.swift

@@ -0,0 +1,109 @@
+// RUN: %target-typecheck-verify-swift -requirement-machine-protocol-signatures=on -requirement-machine-inferred-signatures=on -requirement-machine-abstract-signatures=on
+
+// Reduced from https://github.com/plx/HDXLSIMDSupport.
+
+protocol PA: PB, PC, PD {}
+
+protocol PB: PE where A2 == A3, A4 == A2, A5 == A6, A1 == Self {}
+// expected-warning@-1 {{redundant same-type constraint 'Self.A2' == 'Self.A3'}}
+// expected-warning@-2 {{redundant same-type constraint 'Self.A5' == 'Self.A6'}}
+
+protocol PC: PG where A5 == (A2, A2), A3 == A7.A8 {}
+
+protocol PD: PG where A6 == (A3, A3), A2 == A7.A8 {}
+
+protocol PE: PF where A1.A1 == Self {}
+
+protocol PF: PG {
+  associatedtype A1: PF where A1.A7 == A7, A1.A2 == A3, A1.A3 == A2, A1.A5 == A6, A1.A6 == A5
+  // expected-warning@-1 {{redundant same-type constraint 'Self.A1.A7' == 'Self.A7'}}
+}
+
+protocol PG: PH where A7: PI, A7: BinaryFloatingPoint {
+  associatedtype A2: PJ where A2.A7 == A7
+  associatedtype A3: PJ where A3.A7 == A7
+  associatedtype A4: PJ where A4.A7 == A7
+  associatedtype A5
+  associatedtype A6
+}
+
+protocol PH {
+  associatedtype A7: SIMDScalar
+}
+
+protocol PI {
+  associatedtype A8 where A8.A7 == Self // expected-warning {{redundant same-type constraint 'Self.A8.A7' == 'Self'}}
+  associatedtype A9 where A9.A7 == Self, A9.A8 == A8
+  associatedtype A10 where A10.A7 == Self, A10.A8 == A8, A10.A9 == A9 // expected-warning {{redundant same-type constraint 'Self.A10.A7' == 'Self'}}
+  associatedtype A11 where A11.A7 == Self, A11.A10 == A10 // expected-warning {{redundant same-type constraint 'Self.A11.A7' == 'Self'}}
+  associatedtype A12 where A12.A7 == Self, A12.A11 == A11 // expected-warning {{redundant same-type constraint 'Self.A12.A7' == 'Self'}}
+  associatedtype A13 where A13.A7 == Self, A13.A12 == A12 // expected-warning {{redundant same-type constraint 'Self.A13.A7' == 'Self'}}
+  associatedtype A14: PK where A14.A7 == Self, A14.A13 == A13 // expected-warning {{redundant same-type constraint 'Self.A14.A7' == 'Self'}}
+}
+
+protocol PJ: SIMD, PH where Scalar == A7 {}
+
+protocol PK: SIMD, PH where Scalar == A7 {
+  associatedtype A13: PL where A13.Scalar == Scalar
+}
+
+protocol PL: SIMD, PH where Scalar == A7 {
+  associatedtype A12: PM where A12.Scalar == Scalar
+}
+
+protocol PM: SIMD, PH where Scalar == A7 {
+  associatedtype A11: PN where A11.Scalar == Scalar
+}
+
+protocol PN: SIMD, PH where Scalar == A7 {
+  associatedtype A10: PO where A10.Scalar == Scalar
+}
+
+protocol PO: SIMD, PH where Scalar == A7 {
+  associatedtype A8: PQ where A8.Scalar == Scalar
+  associatedtype A9: PP where A9.Scalar == Scalar
+}
+
+protocol PP: SIMD, PH where Scalar == A7 {
+  associatedtype A8: PQ where A8.Scalar == Scalar
+}
+
+protocol PQ: SIMD, PH where Scalar == A7 {}
+
+func sameType<T>(_: T, _: T) {}
+
+func testPI1<T : PI>(_: T) {
+  sameType(T.A8.A7.self, T.self)
+}
+
+func testPI2<T : PI>(_: T) {
+  sameType(T.A10.A7.self, T.self)
+}
+
+func testPI3<T : PI>(_: T) {
+  sameType(T.A11.A7.self, T.self)
+}
+
+func testPI4<T : PI>(_: T) {
+  sameType(T.A12.A7.self, T.self)
+}
+
+func testPI5<T : PI>(_: T) {
+  sameType(T.A13.A7.self, T.self)
+}
+
+func testPI6<T : PI>(_: T) {
+  sameType(T.A14.A7.self, T.self)
+}
+
+func testPF1<T : PF>(_: T) {
+  sameType(T.A1.A7.self, T.A7.self)
+}
+
+func testPB1<T : PB>(_: T) {
+  sameType(T.A2.self, T.A3.self)
+}
+
+func testPB2<T : PB>(_: T) {
+  sameType(T.A5.self, T.A6.self)
+}