[Bug bootstrap/92433] New: [10 regression] r276645 breaks bootstrap on powerpc

[schwab@linux-m68k.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92433

            Bug ID: 92433
           Summary: [10 regression] r276645 breaks bootstrap on powerpc
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Keywords: build
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: schwab@linux-m68k.org
            Blocks: 91975
  Target Milestone: ---
            Target: powerpc*-*-*

../configure --prefix=/usr --build=powerpc64-suse-linux
--enable-checking=release --enable-shared --with-system-zlib 'CFLAGS=-O2 -g'
'CXXFLAGS=-O2 -g' --with-cpu-64=power4 --enable-secureplt
--with-long-double-128

In file included from ../../gcc/c-family/c-common.h:27,
                 from ../../gcc/config/rs6000/rs6000-c.c:29:
../../gcc/fold-const.h: In function 'tree_node*
altivec_build_resolved_builtin(tree_node**, int, const
altivec_builtin_types*)':
../../gcc/fold-const.h:74:21: error: 'arg_type[1]' may be used uninitialized in
this function [-Werror=maybe-uninitialized]
   74 |    fold_convert_loc (UNKNOWN_LOCATION, T1, T2)
      |                     ^
../../gcc/config/rs6000/rs6000-c.c:6062:8: note: 'arg_type[1]' was declared
here
 6062 |   tree arg_type[3];
      |        ^~~~~~~~
In file included from ../../gcc/c-family/c-common.h:27,
                 from ../../gcc/config/rs6000/rs6000-c.c:29:
../../gcc/fold-const.h:74:21: error: 'arg_type[2]' may be used uninitialized in
this function [-Werror=maybe-uninitialized]
   74 |    fold_convert_loc (UNKNOWN_LOCATION, T1, T2)
      |                     ^
../../gcc/config/rs6000/rs6000-c.c:6062:8: note: 'arg_type[2]' was declared
here
 6062 |   tree arg_type[3];
      |        ^~~~~~~~
cc1plus: all warnings being treated as errors
make[3]: *** [rs6000-c.o] Error 1
make[2]: *** [all-stage2-gcc] Error 2
make[1]: *** [stage2-bubble] Error 2
make: *** [all] Error 2


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91975
[Bug 91975] worse code for small array copy using pointer arithmetic than array
indexing