[stdlib] Mark contains methods on Range/ClosedRange transparent

stdlib/public/core/ClosedRange.swift

@@ -129,6 +129,7 @@ extension ClosedRange: RangeExpression {
   /// - Returns: `true` if `element` is contained in the range; otherwise,
   ///   `false`.
   @inlinable
+  @inline(__always)
   public func contains(_ element: Bound) -> Bool {
     return element >= self.lowerBound && element <= self.upperBound
   }
@@ -383,6 +384,7 @@ extension ClosedRange {
   ///
   /// - Complexity: O(1)
   @_alwaysEmitIntoClient
+  @_transparent
   public func contains(_ other: ClosedRange<Bound>) -> Bool {
     lowerBound <= other.lowerBound && upperBound >= other.upperBound
   }

stdlib/public/core/Range.swift

@@ -94,9 +94,10 @@ extension RangeExpression {
   ///   - pattern: A range.
   ///   - bound: A value to match against `pattern`.
   @inlinable
+  @inline(__always)
   public static func ~= (pattern: Self, value: Bound) -> Bool {
     return pattern.contains(value)
-  }  
+  }
 }
 
 /// A half-open interval from a lower bound up to, but not including, an upper
@@ -194,7 +195,7 @@ public struct Range<Bound: Comparable> {
   /// - Parameter element: The element to check for containment.
   /// - Returns: `true` if `element` is contained in the range; otherwise,
   ///   `false`.
-  @inlinable
+  @_transparent
   public func contains(_ element: Bound) -> Bool {
     return lowerBound <= element && element < upperBound
   }
@@ -682,7 +683,7 @@ extension PartialRangeFrom: RangeExpression {
   ) -> Range<Bound> where C.Index == Bound {
     return self.lowerBound..<collection.endIndex
   }
-  @inlinable // trivial-implementation
+  @_transparent
   public func contains(_ element: Bound) -> Bool {
     return lowerBound <= element
   }
@@ -1074,11 +1075,12 @@ extension Range {
   ///
   /// - Complexity: O(1)
   @_alwaysEmitIntoClient
+  @_transparent
   public func contains(_ other: Range<Bound>) -> Bool {
     other.isEmpty ||
       (lowerBound <= other.lowerBound && upperBound >= other.upperBound)
   }
-  
+
   /// Returns a Boolean value indicating whether the given closed range is
   /// contained within this range.
   ///
@@ -1101,6 +1103,7 @@ extension Range {
   ///
   /// - Complexity: O(1)
   @_alwaysEmitIntoClient
+  @_transparent
   public func contains(_ other: ClosedRange<Bound>) -> Bool {
     lowerBound <= other.lowerBound && upperBound > other.upperBound
   }

test/stdlib/RangeContainsInlining.swift

@@ -0,0 +1,43 @@
+// RUN: %target-swift-emit-ir -primary-file %s 2>&1 | %FileCheck %s
+// RUN: %target-swift-emit-ir -primary-file %s -O 2>&1 | %FileCheck --check-prefixes CHECK,CHECK-OPTIMIZED %s
+// RUN: %target-swift-emit-ir -primary-file %s -Osize 2>&1 | %FileCheck --check-prefixes CHECK,CHECK-OPTIMIZED %s
+
+// We expect calls to `Range.contains` to result in direct bound comparisons in
+// all compilation modes, including unoptimized builds. (These are often used to
+// implement bounds checking.)
+//
+// The sample functions below use bounds of different integer types to avoid
+// them tail-calling each other.
+
+// CHECK-LABEL: define {{.*}} i1 @"$s21RangeContainsInlining08halfOpenB0ySbSnys4Int8VG_ADtF"
+// CHECK-NOT: call swiftcc
+// CHECK: icmp
+// CHECK-NOT: call swiftcc
+// CHECK-LABEL: {{^}}}
+public func halfOpenContains(_ r: Range<Int8>, _ i: Int8) -> Bool {
+  r.contains(i)
+}
+
+// `ClosedRange.contains is only marked `@inline(__always)`; unfortunately it
+// doesn't get inlined in deug builds.
+
+// CHECK-OPTIMIZED-LABEL: define  {{.*}} i1 @"$s21RangeContainsInlining06closedB0ySbSNys5Int16VG_ADtF"
+// CHECK-OPTIMIZED-NOT: call swiftcc
+// CHECK-OPTIMIZED: icmp
+// CHECK-OPTIMIZED-NOT: call swiftcc
+// CHECK-OPTIMIZED-LABEL: {{^}}}
+public func closedContains(_ r: ClosedRange<Int16>, _ i: Int16) -> Bool {
+  r.contains(i)
+}
+
+// `Range.~=` is only marked `@inline(__always)`; unfortunately it doesn't get
+// inlined in deug builds.
+
+// CHECK-OPTIMIZED-LABEL: define {{.*}} i1 @"$s21RangeContainsInlining20halfOpenPatternMatchySbSnys5Int32VG_ADtF"
+// CHECK-OPTIMIZED-NOT: call swiftcc
+// CHECK-OPTIMIZED: icmp
+// CHECK-OPTIMIZED-NOT: call swiftcc
+// CHECK-OPTIMIZED-LABEL: {{^}}}
+public func halfOpenPatternMatch(_ r: Range<Int32>, _ i: Int32) -> Bool {
+  r ~= i
+}