The regression was introduced with this patch:
--- gcc/ChangeLog ---
2000-10-05 Richard Henderson <[EMAIL PROTECTED]>
* c-decl.c (warn_missing_noreturn): Remove.
(c_expand_body): Don't set or check can_reach_end.
* c-tree.h (warn_missing_noreturn): Move ...
* flags.h: ... here.
(can_reach_end): Remove.
* flow.c (check_function_return_warnings): New.
(make_edges): No edge to exit for noreturn sibcalls.
* function.c (expand_function_end): Save the return value
clobber instruction.
(mark_function_status): Mark it.
* function.h (struct function): Add x_clobber_return_insn.
* jump.c (can_reach_end): Remove.
(calculate_can_reach_end): Remove.
(jump_optimize_1): Don't call it.
* output.h (check_function_return_warnings): Declare.
* toplev.c (warn_missing_noreturn): Move from c-decl.c
(rest_of_compilation): Call check_function_return_warnings.
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8602
