diff --git a/libcxx/test/std/iterators/iterator.requirements/iterator.concepts/iterator.concept.random.access/contiguous_iterator.compile.pass.cpp b/libcxx/test/std/iterators/iterator.requirements/iterator.concepts/iterator.concept.random.access/contiguous_iterator.compile.pass.cpp
--- a/libcxx/test/std/iterators/iterator.requirements/iterator.concepts/iterator.concept.random.access/contiguous_iterator.compile.pass.cpp
+++ b/libcxx/test/std/iterators/iterator.requirements/iterator.concepts/iterator.concept.random.access/contiguous_iterator.compile.pass.cpp
@@ -14,6 +14,7 @@
 // concept contiguous_iterator;
 
 #include <iterator>
+#include <compare>
 
 #include "test_iterators.h"
 
@@ -42,11 +43,7 @@
 
     reference operator*() const;
     pointer operator->() const;
-    friend bool operator==(const self&, const self& y);
-    friend bool operator< (const self&, const self& y);
-    friend bool operator<=(const self&, const self& y);
-    friend bool operator> (const self&, const self& y);
-    friend bool operator>=(const self&, const self& y);
+    auto operator<=>(const self&) const = default;
 
     self& operator++();
     self operator++(int);
@@ -68,23 +65,19 @@
 static_assert(std::random_access_iterator<simple_contiguous_iterator>);
 static_assert(std::contiguous_iterator<simple_contiguous_iterator>);
 
-struct missmatch_value_iter_ref_t {
+struct mismatch_value_iter_ref_t {
     typedef std::contiguous_iterator_tag    iterator_category;
     typedef short                           value_type;
     typedef std::ptrdiff_t                  difference_type;
     typedef int*                            pointer;
     typedef int&                            reference;
-    typedef missmatch_value_iter_ref_t      self;
+    typedef mismatch_value_iter_ref_t       self;
 
-    missmatch_value_iter_ref_t();
+    mismatch_value_iter_ref_t();
 
     reference operator*() const;
     pointer operator->() const;
-    friend bool operator==(const self&, const self& y);
-    friend bool operator< (const self&, const self& y);
-    friend bool operator<=(const self&, const self& y);
-    friend bool operator> (const self&, const self& y);
-    friend bool operator>=(const self&, const self& y);
+    auto operator<=>(const self&) const = default;
 
     self& operator++();
     self operator++(int);
@@ -103,8 +96,8 @@
     reference operator[](difference_type n) const;
 };
 
-static_assert(std::random_access_iterator<missmatch_value_iter_ref_t>);
-static_assert(!std::contiguous_iterator<missmatch_value_iter_ref_t>);
+static_assert(std::random_access_iterator<mismatch_value_iter_ref_t>);
+static_assert(!std::contiguous_iterator<mismatch_value_iter_ref_t>);
 
 struct wrong_iter_reference_t {
     typedef std::contiguous_iterator_tag    iterator_category;
@@ -118,11 +111,7 @@
 
     reference operator*() const;
     pointer operator->() const;
-    friend bool operator==(const self&, const self& y);
-    friend bool operator< (const self&, const self& y);
-    friend bool operator<=(const self&, const self& y);
-    friend bool operator> (const self&, const self& y);
-    friend bool operator>=(const self&, const self& y);
+    auto operator<=>(const self&) const = default;
 
     self& operator++();
     self operator++(int);
@@ -156,11 +145,7 @@
 
     reference operator*() const;
     pointer operator->() const;
-    friend bool operator==(const self&, const self& y);
-    friend bool operator< (const self&, const self& y);
-    friend bool operator<=(const self&, const self& y);
-    friend bool operator> (const self&, const self& y);
-    friend bool operator>=(const self&, const self& y);
+    auto operator<=>(const self&) const = default;
 
     self& operator++();
     self operator++(int);
@@ -195,11 +180,7 @@
 
     reference operator*() const;
     pointer operator->() const;
-    friend bool operator==(const self&, const self& y);
-    friend bool operator< (const self&, const self& y);
-    friend bool operator<=(const self&, const self& y);
-    friend bool operator> (const self&, const self& y);
-    friend bool operator>=(const self&, const self& y);
+    auto operator<=>(const self&) const = default;
 
     self& operator++();
     self operator++(int);
@@ -240,11 +221,7 @@
 
     reference operator*() const;
     pointer operator->() const;
-    friend bool operator==(const self&, const self& y);
-    friend bool operator< (const self&, const self& y);
-    friend bool operator<=(const self&, const self& y);
-    friend bool operator> (const self&, const self& y);
-    friend bool operator>=(const self&, const self& y);
+    auto operator<=>(const self&) const = default;
 
     self& operator++();
     self operator++(int);
@@ -254,7 +231,7 @@
 
     self& operator+=(difference_type n);
     self operator+(difference_type n) const;
-    friend self operator+(difference_type n, self x);
+    friend self operator+(difference_type, self) { return self{}; }
 
     self& operator-=(difference_type n);
     self operator-(difference_type n) const;
diff --git a/libcxx/test/std/ranges/range.utility/view.interface/view.interface.pass.cpp b/libcxx/test/std/ranges/range.utility/view.interface/view.interface.pass.cpp
--- a/libcxx/test/std/ranges/range.utility/view.interface/view.interface.pass.cpp
+++ b/libcxx/test/std/ranges/range.utility/view.interface/view.interface.pass.cpp
@@ -43,20 +43,16 @@
 };
 
 struct NotSizedSentinel {
-  using I = int*;
-  using value_type = std::iter_value_t<I>;
-  using difference_type = std::iter_difference_t<I>;
+  using value_type = int;
+  using difference_type = std::ptrdiff_t;
   using iterator_concept = std::forward_iterator_tag;
 
-  NotSizedSentinel() = default;
-  explicit constexpr NotSizedSentinel(I);
-
-  constexpr int &operator*() const { return *value; };
+  explicit NotSizedSentinel() = default;
+  explicit NotSizedSentinel(int*);
+  int& operator*() const;
   NotSizedSentinel& operator++();
   NotSizedSentinel operator++(int);
   bool operator==(NotSizedSentinel const&) const;
-
-  int *value;
 };
 static_assert(std::forward_iterator<NotSizedSentinel>);
 
@@ -127,13 +123,13 @@
   };
 
   struct SentinelType {
-    int *base;
+    int *base_;
     SentinelType() = default;
-    explicit constexpr SentinelType(int *base) : base(base) {}
-    friend constexpr ResultType operator==(ForwardIter const& iter, SentinelType const& sent) noexcept { return {iter.base() == sent.base}; }
-    friend constexpr ResultType operator==(SentinelType const& sent, ForwardIter const& iter) noexcept { return {iter.base() == sent.base}; }
-    friend constexpr ResultType operator!=(ForwardIter const& iter, SentinelType const& sent) noexcept { return {iter.base() != sent.base}; }
-    friend constexpr ResultType operator!=(SentinelType const& sent, ForwardIter const& iter) noexcept { return {iter.base() != sent.base}; }
+    explicit constexpr SentinelType(int *base) : base_(base) {}
+    friend constexpr ResultType operator==(ForwardIter const& iter, SentinelType const& sent) noexcept { return {iter.base() == sent.base_}; }
+    friend constexpr ResultType operator==(SentinelType const& sent, ForwardIter const& iter) noexcept { return {iter.base() == sent.base_}; }
+    friend constexpr ResultType operator!=(ForwardIter const& iter, SentinelType const& sent) noexcept { return {iter.base() != sent.base_}; }
+    friend constexpr ResultType operator!=(SentinelType const& sent, ForwardIter const& iter) noexcept { return {iter.base() != sent.base_}; }
   };
 
   int buff[8] = {0, 1, 2, 3, 4, 5, 6, 7};
diff --git a/libcxx/test/std/strings/string.view/string.view.ops/copy.pass.cpp b/libcxx/test/std/strings/string.view/string.view.ops/copy.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.ops/copy.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.ops/copy.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: gcc-10
+// XFAIL: gcc-10, gcc-11
 //     GCC's __builtin_strlen isn't constexpr yet
 // UNSUPPORTED: LIBCXX-DEBUG-FIXME