[Bug rtl-optimization/23289] New: tail call optimization not performed

[dann at godzilla dot ics dot uci dot edu]

Compiling: 

typedef unsigned int Cardinal;
typedef char *String;
typedef struct _WidgetRec *Widget;

typedef union _XEvent {
        int type;
 long pad[24];
} XEvent;


extern int SendMousePosition (Widget w, XEvent* event);


void
HandleIgnore(Widget w,
      XEvent * event,
      String * params ,
      Cardinal *param_count )
{

    (void) SendMousePosition(w, event);
}

with 4.0 and 4.1 -march=i686 -O2 generates: (the sdiff is shown) 


        .file   "PR.i"                                                  .file  
"PR.i"
        .text                                                           .text
        .p2align 2,,3                                                   .p2align
2,,3
.globl HandleIgnore                                             .globl 
HandleIgnore
        .type   HandleIgnore, @function                                 .type  
HandleIgnore, @function
HandleIgnore:                                                   HandleIgnore:
        pushl   %ebp                                                    pushl   
%ebp
        movl    %esp, %ebp                                              movl   
%esp, %ebp
                                                              >         subl   
$16, %esp
                                                              >         pushl  
12(%ebp)
                                                              >         pushl  
8(%ebp)
                                                              >         call   
SendMousePosition
                                                              >         addl   
$16, %esp
        leave                                                           leave
        jmp     SendMousePosition                             |         ret
        .size   HandleIgnore, .-HandleIgnore                            .size  
HandleIgnore, .-HandleIgnore
        .ident  "GCC: (GNU) 4.0.1 20050727 (Red Hat 4.0.1-5)" |         .ident 
"GCC: (GNU) 4.1.0 20050727 (experimental)"
        .section        .note.GNU-stack,"",@progbits                    .section
       .note.GNU-stack,"",@progbits

Note that 4.1 does not generate a jump to SendMousePosition, but a call. 
This is one of the reasons for the code size regression in PR23153.

-- 
           Summary: tail call optimization not performed
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dann at godzilla dot ics dot uci dot edu
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23289