/*
* Description:
* Moves an instruction from the execution stage to common data bus (if possible)
* Inputs:
* current_cycle: the cycle we are at
* Returns:
* None
*/
void execute_To_CDB(int current_cycle) {
/* ECE552: YOUR CODE GOES HERE */
// Remove all finished stores.
{
int i, j;
for (i = 0; i < FU_INT_SIZE; i++) {
if (fuINT[i] != NULL && IS_STORE(fuINT[i]->op) && current_cycle >= FU_INT_LATENCY + fuINT[i]->tom_execute_cycle) {
remove_insn(fuINT[i], reservINT, RESERV_INT_SIZE);
fuINT[i] = NULL;
}
}
}
// Find oldest instruction that is ready to be broadcasted on the CDB.
{
int i;
instruction_t* insn = NULL;
for (i = 0; i < FU_INT_SIZE; i++) {
if (fuINT[i] != NULL && current_cycle >= FU_INT_LATENCY + fuINT[i]->tom_execute_cycle && (insn == NULL || fuINT[i]->index < insn->index)) {
insn = fuINT[i];
}
}
for (i = 0; i < FU_FP_SIZE; i++) {
if (fuFP[i] != NULL && current_cycle >= FU_FP_LATENCY + fuFP[i]->tom_execute_cycle && (insn == NULL || fuFP[i]->index < insn->index)) {
insn = fuFP[i];
}
}
// If instruction is found, remove it from RSs and FUs.
// Then, set cycle it enters CDB and put it on the CDB.
if (insn != NULL) {
remove_insn(insn, reservINT, RESERV_INT_SIZE);
remove_insn(insn, reservFP, RESERV_FP_SIZE);
remove_insn(insn, fuINT, FU_INT_SIZE);
remove_insn(insn, fuFP, FU_FP_SIZE);
insn->tom_cdb_cycle = current_cycle;
commonDataBus = insn;
}
}
}
void
replace_call_placeholder (rtx insn, sibcall_use_t use)
{
if (use == sibcall_use_tail_recursion)
emit_insn_before (XEXP (PATTERN (insn), 2), insn);
else if (use == sibcall_use_sibcall)
emit_insn_before (XEXP (PATTERN (insn), 1), insn);
else if (use == sibcall_use_normal)
emit_insn_before (XEXP (PATTERN (insn), 0), insn);
else
abort ();
/* Turn off LABEL_PRESERVE_P for the tail recursion label if it
exists. We only had to set it long enough to keep the jump
pass above from deleting it as unused. */
if (XEXP (PATTERN (insn), 3))
LABEL_PRESERVE_P (XEXP (PATTERN (insn), 3)) = 0;
/* "Delete" the placeholder insn. */
remove_insn (insn);
}
static unsigned int
rest_of_handle_simplify_got (void)
{
df_ref ref;
rtx use = NULL_RTX;
int i, n_symbol, n_access = 0;
struct got_access_info* got_accesses;
htab_t var_table = htab_create (VAR_TABLE_SIZE,
htab_hash_pointer,
htab_eq_pointer,
NULL);
rtx pic_reg = targetm.got_access.get_pic_reg ();
gcc_assert (pic_reg);
ref = DF_REG_USE_CHAIN (REGNO (pic_reg));
got_accesses = XNEWVEC(struct got_access_info,
DF_REG_USE_COUNT (REGNO (pic_reg)));
/* Check if all uses of pic_reg are loading global address through the
default method. */
while (ref)
{
rtx_insn* insn = DF_REF_INSN (ref);
/* Check for the special USE insn, it is not a real usage of pic_reg. */
if (GET_CODE (PATTERN (insn)) == USE)
use = insn;
else
{
/* If an insn both set and use pic_reg, it is in the process of
constructing the value of pic_reg. We should also ignore it. */
rtx set = single_set (insn);
if (!(set && SET_DEST (set) == pic_reg))
{
rtx offset_reg;
rtx offset_insn;
rtx symbol = targetm.got_access.loaded_global_var (insn,
&offset_reg,
&offset_insn);
if (symbol)
{
rtx* slot = (rtx*) htab_find_slot (var_table, symbol, INSERT);
if (*slot == HTAB_EMPTY_ENTRY)
*slot = symbol;
gcc_assert (set);
got_accesses[n_access].symbol = symbol;
got_accesses[n_access].offset_reg = offset_reg;
got_accesses[n_access].address_reg = SET_DEST (set);
got_accesses[n_access].load_insn = insn;
got_accesses[n_access].offset_insn = offset_insn;
n_access++;
}
else
{
/* This insn doesn't load a global address, but it has
other unexpected usage of pic_reg, give up. */
free (got_accesses);
htab_delete (var_table);
return 0;
}
}
}
ref = DF_REF_NEXT_REG(ref);
}
/* Check if we can simplify it. */
n_symbol = htab_elements (var_table);
gcc_assert (n_symbol <= n_access);
if (!targetm.got_access.can_simplify_got_access (n_symbol, n_access))
{
free (got_accesses);
htab_delete (var_table);
return 0;
}
/* Rewrite the global address loading insns. */
for (i=0; i<n_access; i++)
targetm.got_access.load_global_address (got_accesses[i].symbol,
got_accesses[i].offset_reg,
got_accesses[i].address_reg,
got_accesses[i].load_insn,
got_accesses[i].offset_insn);
/* Since there is no usage of pic_reg now, we can remove it. */
if (use)
remove_insn (use);
targetm.got_access.clear_pic_reg ();
free (got_accesses);
htab_delete (var_table);
return 0;
}
