[Bug middle-end/35056] [4.3 Regression] ICE in copy_to_mode_reg, at explow.c:621

["rguenther at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #4 from rguenther at suse dot de  2008-02-02 15:57 -------
Subject: Re:  [4.3 Regression] ICE in copy_to_mode_reg,
 at explow.c:621

On Sat, 2 Feb 2008, matz at gcc dot gnu dot org wrote:

> ------- Comment #3 from matz at gcc dot gnu dot org  2008-02-02 15:52 -------
> Reduced by hand:
> 
> % cat x.cc
> enum EBorderStyle { bla = 1 };
> template<typename T, typename U>
> inline bool compareEqual(const T& t, const U& u)
> {
>   return t == u;
> }
> struct S {
>   unsigned m_style : 4;
> };
> 
> void call (S *s, EBorderStyle v)
> {
>   if (!compareEqual(s->m_style, v))
>     s->m_style = v;
> }
> 
> The problem is confusion between the bitmap type and promotion.  If you
> rewrite the compare into a direct expression ("if (s->m_style != v) ...")
> the error doesn't occur.  Anyway, as written this get's generated as
> (004.gimple):
> 
>   <unnamed-unsigned:4> D.1670;
>   unsigned char D.1673;
>   unsigned int D.1668;
> 
>   D.1670 = s->m_style;
>   D.1668 = D.1670;

This is missing a conversion, type checking would complain.

Richard.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35056