void
crx_expand_epilogue (void)
{
rtx return_reg;
/* Nonzero if we need to return and pop only RA. This will generate a
* different insn. This differentiate is for the peepholes for call as last
* statement in function. */
int only_popret_RA = (save_regs[RETURN_ADDRESS_REGNUM]
&& (sum_regs == UNITS_PER_WORD));
/* Return register. */
return_reg = gen_rtx_REG (Pmode, RETURN_ADDRESS_REGNUM);
if (frame_pointer_needed)
/* Restore the stack pointer with the frame pointers value */
emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
if (size_for_adjusting_sp > 0)
emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
GEN_INT (size_for_adjusting_sp)));
if (crx_interrupt_function_p ())
emit_jump_insn (gen_interrupt_return ());
else if (last_reg_to_save == -1)
/* Nothing to pop */
/* Don't output jump for interrupt routine, only retx. */
emit_jump_insn (gen_indirect_jump_return ());
else if (only_popret_RA)
emit_jump_insn (gen_popret_RA_return ());
else
emit_jump_insn (gen_pop_and_popret_return (GEN_INT (sum_regs)));
}
static void
mpushpop_str (char *stringbuffer, const char *mnemonic, char *mask)
{
if (strlen (mask) > 2 || crx_interrupt_function_p ()) /* needs 2-word instr. */
sprintf (stringbuffer, "\n\t%s\tsp, {%s}", mnemonic, mask);
else /* single word instruction */
sprintf (stringbuffer, "\n\t%s\t%s", mnemonic, mask);
}
static void
crx_compute_save_regs (void)
{
unsigned int regno;
/* initialize here so in case the function is no-return it will be -1. */
last_reg_to_save = -1;
/* No need to save any registers if the function never returns. */
if (FUNC_IS_NORETURN_P (current_function_decl))
return;
/* Initialize the number of bytes to be saved. */
sum_regs = 0;
for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
{
if (fixed_regs[regno])
{
save_regs[regno] = 0;
continue;
}
/* If this reg is used and not call-used (except RA), save it. */
if (crx_interrupt_function_p ())
{
if (!current_function_is_leaf && call_used_regs[regno])
/* this is a volatile reg in a non-leaf interrupt routine - save it
* for the sake of its sons. */
save_regs[regno] = 1;
else if (df_regs_ever_live_p (regno))
/* This reg is used - save it. */
save_regs[regno] = 1;
else
/* This reg is not used, and is not a volatile - don't save. */
save_regs[regno] = 0;
}
else
{
/* If this reg is used and not call-used (except RA), save it. */
if (df_regs_ever_live_p (regno)
&& (!call_used_regs[regno] || regno == RETURN_ADDRESS_REGNUM))
save_regs[regno] = 1;
else
save_regs[regno] = 0;
}
}
for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
if (save_regs[regno] == 1)
{
last_reg_to_save = regno;
sum_regs += UNITS_PER_WORD;
}
}
char *
crx_prepare_push_pop_string (int push_or_pop)
{
/* j is the number of registers being saved, takes care that there won't be
* more than 8 in one push/pop instruction */
/* For the register mask string */
static char mask_str[50];
/* i is the index of save_regs[], going from 0 until last_reg_to_save */
int i = 0;
int ra_in_bitmask = 0;
char *return_str;
/* For reversing on the push instructions if there are more than one. */
char *temp_str;
return_str = (char *) xmalloc (120);
temp_str = (char *) xmalloc (120);
/* Initialize */
memset (return_str, 0, 3);
while (i <= last_reg_to_save)
{
/* Prepare mask for one instruction. */
mask_str[0] = 0;
if (i <= SP_REGNUM)
{ /* Add regs unit full or SP register reached */
int j = 0;
while (j < MAX_COUNT && i <= SP_REGNUM)
{
if (save_regs[i])
{
/* TODO to use ra_in_bitmask for detecting last pop is not
* smart it prevents things like: popret r5 */
if (i == RETURN_ADDRESS_REGNUM) ra_in_bitmask = 1;
if (j > 0) strcat (mask_str, ", ");
strcat (mask_str, reg_names[i]);
++j;
}
++i;
}
}
else
{
/* Handle hi/lo savings */
while (i <= last_reg_to_save)
{
if (save_regs[i])
{
strcat (mask_str, "lo, hi");
i = last_reg_to_save + 1;
break;
}
++i;
}
}
if (strlen (mask_str) == 0) continue;
if (push_or_pop == 1)
{
if (crx_interrupt_function_p ())
mpushpop_str (temp_str, "popx", mask_str);
else
{
if (ra_in_bitmask)
{
mpushpop_str (temp_str, "popret", mask_str);
ra_in_bitmask = 0;
}
else mpushpop_str (temp_str, "pop", mask_str);
}
strcat (return_str, temp_str);
}
else
{
/* push - We need to reverse the order of the instructions if there
* are more than one. (since the pop will not be reversed in the
* epilogue */
if (crx_interrupt_function_p ())
mpushpop_str (temp_str, "pushx", mask_str);
else
mpushpop_str (temp_str, "push", mask_str);
strcat (temp_str, return_str);
strcpy (strcat (return_str, "\t"), temp_str);
}
}
if (push_or_pop == 1)
{
/* pop */
if (crx_interrupt_function_p ())
strcat (return_str, "\n\tretx\n");
else if (!FUNC_IS_NORETURN_P (current_function_decl)
&& !save_regs[RETURN_ADDRESS_REGNUM])
strcat (return_str, "\n\tjump\tra\n");
}
/* Skip the newline and the tab in the start of return_str. */
return_str += 2;
return return_str;
}