new file mode 100644
@@ -0,0 +1,95 @@
+// { dg-do run { target c++11 } }
+// PR rtl-optimization/95493 comment 8
+
+#include <array>
+#include <iostream>
+
+struct Point
+{
+ std::array<int, 3> array;
+
+ Point(int x, int y, int z) : array{x, y, z} {}
+
+ Point(const Point & other) : array{other.array} {} // OK if commented
+ //Point(const Point &) = default; // OK
+
+ //Point(Point && other) = default; // OK
+
+ int operator[] (std::size_t i) const { return array[i]; }
+ int& operator[] (std::size_t i) { return array[i]; }
+};
+
+//using Point = std::array<int, 3>; // OK
+
+struct Cell
+{
+ Point point;
+ Cell(Point const& pt) : point(pt) {}
+ int operator[] (std::size_t i) const { return point[i]; }
+ int& operator[] (std::size_t i) { return point[i]; }
+};
+
+//using Cell = Point; // OK
+
+std::ostream & operator<< (std::ostream & out, Cell const& object)
+//std::ostream & operator<< (std::ostream & out, Cell object) // Fails with f2 too
+{
+ for ( std::size_t i = 0; i < 3; ++i )
+ out << object[ i ] << " ";
+ return out;
+}
+
+
+struct DirIterator
+{
+ std::size_t dir;
+ Cell cell;
+
+ DirIterator(Cell c)
+ : dir(0), cell(c)
+ {
+ find(); // OK if commented
+ }
+
+ void find()
+ {
+ //while (dir < 3) // Fails with f2 too
+ while (dir < 3 && (cell[dir] % 2) == 0)
+ ++dir;
+ }
+};
+
+Cell uIncident(Cell c, std::size_t k)
+//Cell uIncident(Cell& c, std::size_t k) // OK
+{
+ --c[k];
+ return c;
+}
+
+Cell uSpel(Point p)
+{
+ for (std::size_t i = 0; i < 3; ++i)
+ p[i] += p[i] + 1;
+ return Cell(p);
+}
+
+
+int main ()
+{
+ Cell c = uSpel(Point{0, 0, 0}); // Fails
+ //Cell c( Point(1, 1, 1) ); // OK
+
+ auto q = DirIterator( c );
+
+ Cell f1 = uIncident( c, q.dir ); // Fails
+ //Cell f1 = uIncident( c, 0 ); // OK
+
+ Cell f2 = f1; // f2 is the right cell that f1 should be
+
+ std::cout << "q.dir = " << q.dir << " ; f1 = " << f1 << " ; f2 = " << f2 << std::endl;
+ //std::cout << "q.dir = " << q.dir << " ; f1 = " << f1[0] << " " << f1[1] << " " << f1[2] << " ; f2 = " << f2[0] << " " << f2[1] << " " << f2[2] << std::endl; // OK
+
+ for (int i = 0; i < 3; ++i)
+ if (f1[i] != f2[i])
+ __builtin_abort();
+}
This was reported on the gcc-help mailing list. The regression started with r10-589 and was fixed by r11-963. gcc/testsuite/ChangeLog: * g++.dg/torture/pr95493-1.C: New test. Tested x86_64-linux. OK for master? commit 03f6e6bea110994d4e1d49a2469f808082d5bded Author: Jonathan Wakely <jwakely@redhat.com> Date: Tue Jun 16 17:57:23 2020 +0100 middle-end: Add another testcase for PR 95493 This was reported on the gcc-help mailing list. The regression started with r10-589 and was fixed by r11-963. gcc/testsuite/ChangeLog: * g++.dg/torture/pr95493-1.C: New test.