Index: gcc/tree-ssa-pre.c
===================================================================
--- gcc/tree-ssa-pre.c	(revision 191969)
+++ gcc/tree-ssa-pre.c	(working copy)
@@ -4820,6 +4820,13 @@ do_pre (void)
 
   free_scc_vn ();
 
+  /* Tail merging invalidates the virtual SSA web, together with
+     cfg-cleanup opportunities exposed by PRE this will wreck the
+     SSA updating machinery.  So make sure to run update-ssa
+     manually, before eventually scheduling cfg-cleanup as part of
+     the todo.  */
+  update_ssa (TODO_update_ssa_only_virtuals);
+
   return todo;
 }
 
@@ -4845,8 +4852,7 @@ struct gimple_opt_pass pass_pre =
   0,					/* properties_provided */
   0,					/* properties_destroyed */
   TODO_rebuild_alias,			/* todo_flags_start */
-  TODO_update_ssa_only_virtuals  | TODO_ggc_collect
-  | TODO_verify_ssa /* todo_flags_finish */
+  TODO_ggc_collect | TODO_verify_ssa	/* todo_flags_finish */
  }
 };
 
Index: gcc/testsuite/g++.dg/torture/pr54735.C
===================================================================
--- gcc/testsuite/g++.dg/torture/pr54735.C	(revision 0)
+++ gcc/testsuite/g++.dg/torture/pr54735.C	(working copy)
@@ -0,0 +1,179 @@
+// { dg-do compile }
+
+class Gmpfr
+{};
+class M : Gmpfr
+{
+public:
+  Gmpfr infconst;
+  M(int);
+};
+template<typename>struct A;
+template<typename, int, int, int = 0 ? : 0, int = 0, int = 0>class N;
+template<typename>class O;
+template<typename>struct B;
+struct C
+{
+  enum
+  { value };
+};
+class D
+{
+public:
+  enum
+  { ret };
+};
+struct F
+{
+  enum
+  { ret = 0 ? : 0 };
+};
+template<typename Derived>struct G
+{
+  typedef O<Derived>type;
+};
+struct H
+{
+  void operator * ();
+};
+struct I
+{
+  enum
+  { RequireInitialization = C::value ? : 0, ReadCost };
+};
+template<typename Derived>struct J
+{
+  enum
+  { ret = A<Derived>::InnerStrideAtCompileTime };
+};
+template<typename Derived>struct K
+{
+  enum
+  { ret = A<Derived>::OuterStrideAtCompileTime };
+};
+template<typename Derived>class P : H
+{
+public:
+  using H::operator *;
+  typedef typename A<Derived>::Scalar Scalar;
+  enum
+  { RowsAtCompileTime                                        =
+      A<Derived>::RowsAtCompileTime, ColsAtCompileTime       =
+      A<Derived>::ColsAtCompileTime, SizeAtCompileTime       =
+      F::ret, MaxRowsAtCompileTime                           =
+      A<Derived>::MaxRowsAtCompileTime, MaxColsAtCompileTime =
+      A<Derived>::MaxColsAtCompileTime, MaxSizeAtCompileTime =
+      F::ret, Flags                                          =
+      A<Derived>::Flags ? : 0 ? : 0, CoeffReadCost           =
+      A<Derived>::CoeffReadCost, InnerStrideAtCompileTime    =
+      J<Derived>::ret, OuterStrideAtCompileTime              = K<Derived>::ret };
+  B<Derived> operator << (const Scalar&);
+};
+
+template<typename Derived>class O : public P<Derived>
+{};
+
+template<int _Cols>class L
+{
+public:
+
+  int cols()
+  {
+    return _Cols;
+  }
+};
+template<typename Derived>class Q : public G<Derived>::type
+{
+public:
+  typedef typename G<Derived>::type   Base;
+  typedef typename A<Derived>::Index  Index;
+  typedef typename A<Derived>::Scalar Scalar;
+  L<Base::ColsAtCompileTime> m_storage;
+  Index cols()
+  {
+    return m_storage.cols();
+  }
+
+  Scalar& coeffRef(Index,
+                   Index);
+};
+
+template<typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows,
+         int _MaxCols>struct A<N<_Scalar, _Rows, _Cols, _Options, _MaxRows,
+                                 _MaxCols> >
+{
+  typedef _Scalar Scalar;
+  typedef int     Index;
+  enum
+  { RowsAtCompileTime, ColsAtCompileTime                              =
+      _Cols, MaxRowsAtCompileTime, MaxColsAtCompileTime, Flags        =
+      D::ret, CoeffReadCost                                           =
+      I::ReadCost, InnerStrideAtCompileTime, OuterStrideAtCompileTime =
+      0 ? : 0 };
+};
+template<typename _Scalar, int, int _Cols, int, int,
+         int>class N : public Q<N<_Scalar, 0, _Cols> >
+{
+public:
+  Q<N> Base;
+  template<typename T0, typename T1>N(const T0&,
+                                      const T1&);
+};
+void
+__assert_fail(int)
+throw() __attribute__((__noreturn__));
+template<typename XprType>struct B
+{
+  typedef typename XprType::Scalar Scalar;
+  typedef typename XprType::Index  Index;
+  B(XprType & p1, const Scalar &) : m_xpr(p1), m_col(),
+                                    m_currentBlockRows(1)
+  {} B& operator, (const Scalar&)
+  {
+    Index a;
+
+    if (m_col == m_xpr.cols())
+    {
+      m_col              = 0;
+      m_currentBlockRows = 1;
+      a && "Too       " ? static_cast<void>(0) : __assert_fail(0);
+    }
+    m_col < m_xpr.cols()
+    && "Too       " ? static_cast<void>(0) : __assert_fail(1);
+    m_currentBlockRows ? static_cast<void>(0) : __assert_fail(4);
+    m_xpr.coeffRef(0, m_col++) = 0;
+    return *this;
+  }
+  ~B()
+  {
+    1 + m_currentBlockRows && m_col
+    && "Too       " ? static_cast<void>(0) : __assert_fail(0);
+  }
+
+  XprType& m_xpr;
+  Index    m_col;
+  Index    m_currentBlockRows;
+};
+
+template<typename Derived>B<Derived>P<
+  Derived >::operator << (const Scalar&)
+{
+    return B<Derived>(*static_cast<Derived *>(this), 0);
+}
+
+template<class NT, int s>void
+               check_()
+{
+    N<NT, 0, s>m(0, 0);
+    m << 0, 0, 0, 0;
+}
+
+template<class NT>void check()
+{
+    check_<NT, 3>();
+}
+
+int main()
+{
+    check<M>();
+}