[Bug target/56184] New: Internal compiler error in push_reload during bootstrap stage 2

[mgretton at sourceware dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56184

             Bug #: 56184
           Summary: Internal compiler error in push_reload during
                    bootstrap stage 2
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mgretton@sourceware.org


Created attachment 29337
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29337
Reduced test case

When bootstrapping on an ARM target I get the following error:

/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/build/./prev-gcc/xg++
-B/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/build/./prev-gcc/
-B/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/install/arm-linux-gnueabi/bin/
-nostdinc++
-B/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/build/prev-arm-linux-gnueabi/libstdc++-v3/src/.libs
-B/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/build/prev-arm-linux-gnueabi/libstdc++-v3/libsupc++/.libs
-I/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/build/prev-arm-linux-gnueabi/libstdc++-v3/include/arm-linux-gnueabi
-I/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/build/prev-arm-linux-gnueabi/libstdc++-v3/include
-I/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/gcc-4.8~svn195568/libstdc++-v3/libsupc++
-L/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/build/prev-arm-linux-gnueabi/libstdc++-v3/src/.libs
-L/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/build/prev-arm-linux-gnueabi/libstdc++-v3/libsupc++/.libs
-c   -g -O2 -gtoggle -DIN_GCC   -fno-exceptions -fno-rtti
-fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings
-Wcast-qual -Wmissing-format-attribute -pedantic -Wno-long-long
-Wno-variadic-macros -Wno-overlength-strings -Werror -fno-common 
-DHAVE_CONFIG_H -I. -I. -I../../../gcc-4.8~svn195568/gcc
-I../../../gcc-4.8~svn195568/gcc/. -I../../../gcc-4.8~svn195568/gcc/../include
-I../../../gcc-4.8~svn195568/gcc/../libcpp/include 
-I../../../gcc-4.8~svn195568/gcc/../libdecnumber
-I../../../gcc-4.8~svn195568/gcc/../libdecnumber/dpd -I../libdecnumber
-I../../../gcc-4.8~svn195568/gcc/../libbacktrace   
../../../gcc-4.8~svn195568/gcc/lto-streamer-out.c -o lto-streamer-out.o
../../../gcc-4.8~svn195568/gcc/lto-streamer-in.c: In function 'void
lto_input_function_body(lto_file_decl_data*, tree, const char*)':
../../../gcc-4.8~svn195568/gcc/lto-streamer-in.c:1003:1: internal compiler
error: in push_reload, at reload.c:1014
 }
 ^
0x6d1a41 push_reload(rtx_def*, rtx_def*, rtx_def**, rtx_def**, reg_class,
machine_mode, machine_mode, int, int, int, reload_type)
    ../../../gcc-4.8~svn195568/gcc/reload.c:1012
0x6daa8d find_reloads(rtx_def*, int, int, int, short*)
    ../../../gcc-4.8~svn195568/gcc/reload.c:4099
0x6e6d8b calculate_needs_all_insns
    ../../../gcc-4.8~svn195568/gcc/reload1.c:1520
0x6e560b reload(rtx_def*, int)
    ../../../gcc-4.8~svn195568/gcc/reload1.c:941
0x5f1843 do_reload
    ../../../gcc-4.8~svn195568/gcc/ira.c:4635
0x5f1a33 rest_of_handle_reload
    ../../../gcc-4.8~svn195568/gcc/ira.c:4736
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
make[7]: *** [lto-streamer-in.o] Error 1


GCC has been configured as follows:

--prefix=/cbuild/slaves/tcpandas/gcc-4.8~svn195568/gcc/default/install
--enable-languages=c,c++,objc,obj-c++,fortran,lto --enable-linker-build-id
--with-mode=thumb --with-arch=armv7-a --with-tune=cortex-a9 --with-fpu=neon
--with-float=softfp --build=arm-linux-gnueabi


Attached test case is a reduced version which triggers the same problem with a
cross-compiler configured as:

Configured with: /work/sources/gcc-fsf/master/configure
--target=arm-none-linux-gnueabi --prefix=/work/builds/gcc-fsf-master/tools
--with-sysroot=/work/builds/gcc-fsf-master/sysroot-arm-none-linux-gnueabi
--disable-libssp --disable-libgomp --disable-libmudflap
--enable-languages=c,c++ --with-arch=armv7-a --with-fpu=vfpv3-d16
--with-float=softfp --with-thumb

Attached test case invoked by:

.../arm-none-linux-gnueabi-g++  -c    -O2 -mthumb -march=armv7-a -mfpu=neon
-mfloat-abi=softfp -mtune=cortex-a9 test.ii

Bisecting suggests the issue was introduced by subversion revision 194558:

    2012-12-17  Andrew Stubbs  <ams@codesourcery.com>
            Ulrich Weigand  <ulrich.weigand@linaro.org>

        gcc/
        * config/arm/arm.md (zero_extend<mode>di2): Add extra alternatives
        for NEON registers.
        Add alternative for one-instruction extend-in-place.
        (extend<mode>di2): Likewise.
        Add constraints for Thumb-mode memory loads.
        Prevent extend splitters doing NEON alternatives.
        * config/arm/iterators.md (qhs_extenddi_cstr, qhs_zextenddi_cstr):
        Adjust constraints to add new alternatives.
        * config/arm/neon.md: Add splitters for zero- and sign-extend.

        gcc/testsuite/
        * gcc.target/arm/neon-extend-1.c: New file.
        * gcc.target/arm/neon-extend-2.c: New file.