SH-ELF: gcc-3.0.2 and PR always saved unnecessarily

[tm at kloo dot net (tm)]

version: gcc-3.0.2
   host: i386-linux
 target: sh-elf

I've noticed that GCC generates code which always saves the PR, which is rather
wasteful on short leaf functions.

For example, this code:

void main(void) { }

when compiled with -O2 -m4 -S produces:

_main:
        mov.l   r14,@-r15
        sts.l   pr,@-r15
        mov     r15,r14
        mov     r14,r15
        lds.l   @r15+,pr
        rts
        mov.l   @r15+,r14

I've narrowed this down to config/sh/sh.c, to this chunk of code:

int
initial_elimination_offset (from, to)
     int from;
     int to;
{
  int regs_saved;
  int total_saved_regs_space;
  int total_auto_space;
  int save_flags = target_flags;

  int live_regs_mask, live_regs_mask2;

  if (from == RETURN_ADDRESS_POINTER_REGNUM)
      /* Kludge: since we assume that the return address is on the stack,
         make it so.  N.B. We rely on RETURN_ADDRESS_POINTER_REGNUM being
         processed before ARG_POINTER_REGNUM here.  */
      regs_ever_live[PR_REG] = 1;

It looks like this kludge has been removed from gcc in CVS. Does anybody
know if this code is also obsolete in gcc-3.0.2 as well?

Toshi

                                                                              ~