[Bug target/53559] New: ICE on altivec builtins stv[l|r]x[l]

[edmar at freescale dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53559

             Bug #: 53559
           Summary: ICE on altivec builtins stv[l|r]x[l]
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: ed...@freescale.com


Created attachment 27545
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27545
config/rs6000/altivec.md (altivec_stvlx): Change machine mode of operands.

When compiling any code that uses __builtin_altivec_stvlx
I get an ICE:

test.c: In function ‘sc1’:
test.c:7:27: internal compiler error: in copy_to_mode_reg, at explow.c:647
   __builtin_altivec_stvlx (v,a,p);
                           ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Test case is:
// -O2 -maltivec -mcpu=cell -c
#include <altivec.h>

typedef __vector signed char vsc;
void sc1(vsc v, long a, void *p)
{
  __builtin_altivec_stvlx (v,a,p);
}


Compiled with:
gcc  -O2 -maltivec -mcpu=cell -c test.c
Target:
ppc64

I traced that ICE back as far as gcc-4.4.4
(Fedora 12 running on a G5:
Using built-in specs.
Target: ppc64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla
--enable-bootstrap --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk
--disable-dssi --enable-plugin
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
--enable-libgcj-multifile --enable-java-maintainer-mode
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib
--with-ppl --with-cloog --enable-secureplt --with-long-double-128
--build=ppc64-redhat-linux --target=ppc64-redhat-linux --with-cpu=default32
Thread model: posix
gcc version 4.4.4 20100630 (Red Hat 4.4.4-10) (GCC) )




I found that the RTL for the builtin is created with mode V16QI,
but the RTL patterns in altivec.md are defined with mode V4SI.

The patch attached was tested 3 months ago on branches 4.5, 4.6,
4.7 and on trunk (4.8) with no regressions.

Please let me know if the proposed solution is the right way
to fix this. I will re-test the patch and submit it for approval.

Thanks,
Edmar