http://gcc.gnu.org/bugzilla/show_bug.cgi?id=61092
--- Comment #2 from Uroš Bizjak <ubizjak at gmail dot com> --- The failure can be triggered with an attached precompiled source using a crosscompiler from x86-64 to alphaev68-pc-linux-gnu, with -O2: ~/gcc-build-xxx/gcc/cc1plus -O2 -quiet wide-int.ii cc1plus: error: no include path in which to search for stdc-predef.h ../../gcc-svn/trunk/gcc/wide-int.cc: In function ‘unsigned int wi::mul_internal(long int*, const long int*, unsigned int, const long int*, unsigned int, unsigned int, signop, bool*, bool)’: ../../gcc-svn/trunk/gcc/wide-int.cc:1269:70: sorry, unimplemented: unexpected AST of kind mult_highpart_expr ../../gcc-svn/trunk/gcc/wide-int.cc:1269:70: internal compiler error: in potential_constant_expression_1, at cp/semantics.c:10575 0x6a1a3f potential_constant_expression_1 ../../gcc-svn/trunk/gcc/cp/semantics.c:10575 0x6a9c2c potential_constant_expression(tree_node*) ../../gcc-svn/trunk/gcc/cp/semantics.c:10585 0x6a9cb3 maybe_constant_value(tree_node*) ../../gcc-svn/trunk/gcc/cp/semantics.c:9927 ...