[Bug c/32751] New: Missed optimization with function ptrs even when inline

["rusty at rustcorp dot com dot au" <gcc-bugzilla at gcc dot gnu dot org>]

I expect "one" not to be emitted when compiling this with -O3:

=== cut here ===
static inline unsigned long one(void)
{
        return 1;
}
static inline unsigned long call(unsigned long (*fn)(void))
{
        return fn();
}
int test_call(void)
{
        return call(one);
}
=== cut here ===
        .file   "foo.c"
        .text
        .p2align 4,,15
        .type   one, @function
one:
        pushl   %ebp
        movl    $1, %eax
        movl    %esp, %ebp
        popl    %ebp
        ret
        .size   one, .-one
        .p2align 4,,15
.globl test_call
        .type   test_call, @function
test_call:
        pushl   %ebp
        movl    %esp, %ebp
        popl    %ebp
        jmp     one
        .size   test_call, .-test_call
        .ident  "GCC: (GNU) 4.1.2 (Ubuntu 4.1.2-0ubuntu4)"
        .section        .note.GNU-stack,"",@progbits
=== cut here ===

The lack of this optimization means that it's inefficient to write generic
routines (eg. see include/linux/rbtree.h in the Linux sources).

Thanks,
Rusty.


-- 
           Summary: Missed optimization with function ptrs even when inline
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rusty at rustcorp dot com dot au
 GCC build triplet: i486-linux-gnu
  GCC host triplet: i486-linux-gnu
GCC target triplet: i486-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32751