Re: bin/46978: internal compiler error building qt4-libs

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

The following reply was made to PR bin/46978; it has been noted by GNATS.

From: Joerg Sonnenberger <joerg%britannica.bec.de@localhost>
To: Nick Hudson <skrll%netbsd.org@localhost>
Cc: gnats-bugs%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, 
netbsd-bugs%netbsd.org@localhost,
        apb%cequrux.com@localhost, joerg%netbsd.org@localhost
Subject: Re: bin/46978: internal compiler error building qt4-libs
Date: Mon, 24 Sep 2012 21:55:15 +0200

 New test case is:
 
 typedef int __attribute__((vector_size(8))) m64;
 m64 _mm_setzero_si64 ();
 m64 _negate (m64, m64);
 void
 qt_blend_color_argb_x86 ()
 {
     m64 mmx_0x00ff = _mm_setzero_si64 ();
     m64 mmx_0x0000 = _mm_setzero_si64 ();
     m64 ca;
     m64 ica = _negate (ca, mmx_0x00ff);
 }
 
 Compiling this with -mmx -O2 results in the given crash.
 Unpatched gcc shows the same behavior with -mpreferred-stack-boundary=2.
 
 Best bet so far is that the memory alignment is computed too early,
 before the stack alignment is finalized.
 
 Joerg