[Bug c/34589] New: noreturn calls: gcc generates call instead of jump

["vyzo at media dot mit dot edu" <gcc-bugzilla at gcc dot gnu dot org>]

When noreturn functions call other noreturn functions, gcc still generates a
call instruction instead of a jump instruction. This result in slightly slower
execution and a small space leak on the stack, which affects higher level
language compilers that target gnu C as intermediate language and use CPS with
cheney on stack.

Example:
see attached whycall.c and whycall.s is gcc-4.1.2 output at -O2 for x86-64.

bar:
 ...
 call foo

The more efficient version would be to generate 'jmp foo'


-- 
           Summary: noreturn calls: gcc generates call instead of jump
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: vyzo at media dot mit dot edu
GCC target triplet: x86_64-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34589