Re: patch to fix PR55106

[Vladimir Makarov]

On 12-10-28 8:49 PM, H.J. Lu wrote:

On Sun, Oct 28, 2012 at 5:43 PM, Vladimir Makarov <vmaka...@redhat.com> wrote:

   The following patch fixes PR55106.  A value in GENERAL_REGS is inherited
into a move with destination pseudo of SSE_REGS.  It results into secondary
move for which inheritance is tried again an again.  It means cycling LRA
passes.

   The patch was successfully bootstrapped on x86/x86-64.

   Committed as rev. 192904.

2012-10-28  Vladimir Makarov  <vmaka...@redhat.com>

     PR rtl-optimization/55106
     * lra-constraints.c (skip_usage_debug_insns): New function.
     (check_secondary_memory_needed_p): Ditto.
     (inherit_reload_reg): Use the new functions.  Improve debug
     output.

Please add the testcase at

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55106#c1

I've committed the following patch.

2012-10-29  Vladimir Makarov  <vmaka...@redhat.com>

        PR rtl-optimization/55106
        * g++.dg/pr55106.C: New.

Index: testsuite/g++.dg/pr55106.C
===================================================================
--- testsuite/g++.dg/pr55106.C  (revision 0)
+++ testsuite/g++.dg/pr55106.C  (working copy)
@@ -0,0 +1,67 @@
+/* { dg-do compile } */
+/* { dg-options "-c -O3" } */
+template<typename _Tp> struct A {
+  typedef _Tp *pointer;
+  typedef _Tp& reference;
+  typedef _Tp& const_reference;
+  template<typename>struct rebind
+  {
+    typedef A other;
+  };
+};
+
+template<typename _Alloc>struct __alloc_traits
+{
+  typedef typename _Alloc::pointer         pointer;
+  typedef typename _Alloc::reference       reference;
+  typedef typename _Alloc::const_reference const_reference;
+  template<typename _Tp>struct rebind
+  {
+    typedef typename _Alloc::template rebind<_Tp>::other other;
+  };
+};
+template<typename _Tp, typename _Alloc>struct B
+{
+  typedef typename __alloc_traits<_Alloc>::template rebind<
+      _Tp>::other _Tp_alloc_type;
+  typedef typename __alloc_traits<_Tp_alloc_type>::pointer pointer;
+  struct F
+  {
+    pointer _M_start;
+  };
+  F _M_impl;
+};
+template<typename _Tp, typename _Alloc = A<_Tp> >class vec : B<_Tp, _Alloc>{
+  typedef B<_Tp, _Alloc>                 _Base;
+  typedef typename _Base::_Tp_alloc_type _Tp_alloc_type;
+  typedef __alloc_traits<_Tp_alloc_type> _Alloc_traits;
+
+public:
+  typedef _Tp                                     value_type;
+  typedef typename _Alloc_traits::reference       reference;
+  typedef typename _Alloc_traits::const_reference const_reference;
+  reference operator[](int p1)
+  {
+    return *(this->_M_impl._M_start + p1);
+  }
+
+  const_reference operator[](long) const;
+};
+
+int a[17];
+class C {
+  vec<int> m_value;
+  void opModDivGuts(const C&);
+  int mostSetBitP1() const;
+};
+void C::opModDivGuts(const C& p1)
+{
+  int b = p1.mostSetBitP1(), c = b + 1;
+  int d[16];
+
+  for (int i = c; i; i--)
+    a[i] = p1.m_value[i] << b;
+
+  for (int i = 0; i < c; i++)
+    m_value[i] = d[i] >> b << -b;
+}