From: Patrick Palka <ppalka@redhat.com>
Date: Mon, 28 Sep 2020 15:54:57 +0000 (-0400)
Subject: libstdc++: Reduce the size of an unbounded iota_view
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=623443357e6092067b4cf98cc6c0aeff7560b98d;p=gcc.git

libstdc++: Reduce the size of an unbounded iota_view

libstdc++-v3/ChangeLog:

	* include/std/ranges (iota_view::_M_bound): Give it
	[[no_unique_address]].
	* testsuite/std/ranges/iota/iota_view.cc: Check that an
	unbounded iota_view has minimal size.
---

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index ed04fa0001d..964a2b616a6 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -511,7 +511,7 @@ namespace ranges
       };
 
       _Winc _M_value = _Winc();
-      _Bound _M_bound = _Bound();
+      [[no_unique_address]] _Bound _M_bound = _Bound();
 
     public:
       iota_view() = default;
diff --git a/libstdc++-v3/testsuite/std/ranges/iota/iota_view.cc b/libstdc++-v3/testsuite/std/ranges/iota/iota_view.cc
index 65d166fbd3b..8a33e10a093 100644
--- a/libstdc++-v3/testsuite/std/ranges/iota/iota_view.cc
+++ b/libstdc++-v3/testsuite/std/ranges/iota/iota_view.cc
@@ -77,6 +77,9 @@ test04()
   VERIFY( it == v.end() );
 }
 
+// Verify we optimize away the 'bound' data member of an unbounded iota_view.
+static_assert(sizeof(std::ranges::iota_view<char>) == 1);
+
 int
 main()
 {