#include "tree-pass.h"
#include "df.h"
+/* We keep linked lists of DU_HEAD structures, each of which describes
+ a chain of occurrences of a reg. */
+struct du_head
+{
+ /* The next chain. */
+ struct du_head *next_chain;
+ /* The first and last elements of this chain. */
+ struct du_chain *first, *last;
+ /* Describes the register being tracked. */
+ unsigned regno, nregs;
+ /* Nonzero if the chain crosses a call. */
+ unsigned int need_caller_save_reg:1;
+ /* Nonzero if the chain is finished. */
+ unsigned int terminated:1;
+};
+
+/* This struct describes a single occurrence of a register. */
struct du_chain
{
- struct du_chain *next_chain;
+ /* Links to the next occurrence of the register. */
struct du_chain *next_use;
+ /* The insn where the register appears. */
rtx insn;
+ /* The location inside the insn. */
rtx *loc;
+ /* The register class required by the insn at this location. */
ENUM_BITFIELD(reg_class) cl : 16;
- unsigned int need_caller_save_reg:1;
+ /* Nonzero if the register is subject to earlyclobber. */
unsigned int earlyclobber:1;
};
static struct obstack rename_obstack;
-static void do_replace (struct du_chain *, int);
+static void do_replace (struct du_head *, int);
static void scan_rtx_reg (rtx, rtx *, enum reg_class,
enum scan_actions, enum op_type, int);
static void scan_rtx_address (rtx, rtx *, enum reg_class,
enum scan_actions, enum machine_mode);
static void scan_rtx (rtx, rtx *, enum reg_class, enum scan_actions,
enum op_type, int);
-static struct du_chain *build_def_use (basic_block);
-static void dump_def_use_chain (struct du_chain *);
+static struct du_head *build_def_use (basic_block);
+static void dump_def_use_chain (struct du_head *);
static void note_sets (rtx, const_rtx, void *);
static void clear_dead_regs (HARD_REG_SET *, enum reg_note, rtx);
static void merge_overlapping_regs (basic_block, HARD_REG_SET *,
- struct du_chain *);
+ struct du_head *);
/* Called through note_stores. Find sets of registers, and
record them in *DATA (which is actually a HARD_REG_SET *). */
}
}
-/* For a def-use chain CHAIN in basic block B, find which registers overlap
+/* For a def-use chain HEAD in basic block B, find which registers overlap
its lifetime and set the corresponding bits in *PSET. */
static void
merge_overlapping_regs (basic_block b, HARD_REG_SET *pset,
- struct du_chain *chain)
+ struct du_head *head)
{
- struct du_chain *t = chain;
+ struct du_chain *t;
rtx insn;
HARD_REG_SET live;
df_ref *def_rec;
if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
SET_HARD_REG_BIT (live, DF_REF_REGNO (def));
}
+
+ t = head->first;
insn = BB_HEAD (b);
while (t)
{
note_stores (PATTERN (insn), note_sets, (void *) &live);
/* Only record currently live regs if we are inside the
reg's live range. */
- if (t != chain)
+ if (t != head->first)
IOR_HARD_REG_SET (*pset, live);
clear_dead_regs (&live, REG_UNUSED, REG_NOTES (insn));
}
FOR_EACH_BB (bb)
{
- struct du_chain *all_chains = 0;
+ struct du_head *all_chains = 0;
HARD_REG_SET unavailable;
HARD_REG_SET regs_seen;
{
int new_reg, best_new_reg;
int n_uses;
- struct du_chain *this_du = all_chains;
+ struct du_head *this_head = all_chains;
struct du_chain *tmp;
HARD_REG_SET this_unavailable;
- int reg = REGNO (*this_du->loc);
+ int reg = this_head->regno;
int i;
- all_chains = this_du->next_chain;
+ all_chains = this_head->next_chain;
best_new_reg = reg;
/* Count number of uses, and narrow the set of registers we can
use for renaming. */
n_uses = 0;
- for (tmp = this_du; tmp; tmp = tmp->next_use)
+ for (tmp = this_head->first; tmp; tmp = tmp->next_use)
{
if (DEBUG_INSN_P (tmp->insn))
continue;
if (n_uses < 2)
continue;
- if (this_du->need_caller_save_reg)
+ if (this_head->need_caller_save_reg)
IOR_HARD_REG_SET (this_unavailable, call_used_reg_set);
- merge_overlapping_regs (bb, &this_unavailable, this_du);
+ merge_overlapping_regs (bb, &this_unavailable, this_head);
/* Now potential_regs is a reasonable approximation, let's
have a closer look at each register still in there. */
for (new_reg = 0; new_reg < FIRST_PSEUDO_REGISTER; new_reg++)
{
- int nregs = hard_regno_nregs[new_reg][GET_MODE (*this_du->loc)];
+ enum machine_mode mode = GET_MODE (*this_head->first->loc);
+ int nregs = hard_regno_nregs[new_reg][mode];
for (i = nregs - 1; i >= 0; --i)
if (TEST_HARD_REG_BIT (this_unavailable, new_reg + i)
/* See whether it accepts all modes that occur in
definition and uses. */
- for (tmp = this_du; tmp; tmp = tmp->next_use)
+ for (tmp = this_head->first; tmp; tmp = tmp->next_use)
if ((! HARD_REGNO_MODE_OK (new_reg, GET_MODE (*tmp->loc))
&& ! DEBUG_INSN_P (tmp->insn))
- || (tmp->need_caller_save_reg
+ || (this_head->need_caller_save_reg
&& ! (HARD_REGNO_CALL_PART_CLOBBERED
(reg, GET_MODE (*tmp->loc)))
&& (HARD_REGNO_CALL_PART_CLOBBERED
if (dump_file)
{
fprintf (dump_file, "Register %s in insn %d",
- reg_names[reg], INSN_UID (this_du->insn));
- if (this_du->need_caller_save_reg)
+ reg_names[reg], INSN_UID (this_head->first->insn));
+ if (this_head->need_caller_save_reg)
fprintf (dump_file, " crosses a call");
}
if (dump_file)
fprintf (dump_file, ", renamed as %s\n", reg_names[best_new_reg]);
- do_replace (this_du, best_new_reg);
+ do_replace (this_head, best_new_reg);
tick[best_new_reg] = ++this_tick;
df_set_regs_ever_live (best_new_reg, true);
}
}
static void
-do_replace (struct du_chain *chain, int reg)
+do_replace (struct du_head *head, int reg)
{
- unsigned int base_regno = REGNO (*chain->loc);
+ struct du_chain *chain;
+ unsigned int base_regno = head->regno;
- gcc_assert (! DEBUG_INSN_P (chain->insn));
+ gcc_assert (! DEBUG_INSN_P (head->first->insn));
- while (chain)
+ for (chain = head->first; chain; chain = chain->next_use)
{
unsigned int regno = ORIGINAL_REGNO (*chain->loc);
- struct reg_attrs * attr = REG_ATTRS (*chain->loc);
+ struct reg_attrs *attr = REG_ATTRS (*chain->loc);
int reg_ptr = REG_POINTER (*chain->loc);
if (DEBUG_INSN_P (chain->insn) && REGNO (*chain->loc) != base_regno)
}
df_insn_rescan (chain->insn);
- chain = chain->next_use;
}
}
-static struct du_chain *open_chains;
-static struct du_chain *closed_chains;
+static struct du_head *open_chains;
+static struct du_head *closed_chains;
static void
scan_rtx_reg (rtx insn, rtx *loc, enum reg_class cl,
enum scan_actions action, enum op_type type, int earlyclobber)
{
- struct du_chain **p;
+ struct du_head **p;
rtx x = *loc;
enum machine_mode mode = GET_MODE (x);
- int this_regno = REGNO (x);
- int this_nregs = hard_regno_nregs[this_regno][mode];
+ unsigned this_regno = REGNO (x);
+ unsigned this_nregs = hard_regno_nregs[this_regno][mode];
if (action == mark_write)
{
if (type == OP_OUT)
{
+ struct du_head *head = XOBNEW (&rename_obstack, struct du_head);
struct du_chain *this_du = XOBNEW (&rename_obstack, struct du_chain);
+ head->next_chain = open_chains;
+ open_chains = head;
+ head->first = head->last = this_du;
+ head->regno = this_regno;
+ head->nregs = this_nregs;
+ head->need_caller_save_reg = 0;
+ head->terminated = 0;
+
this_du->next_use = 0;
- this_du->next_chain = open_chains;
this_du->loc = loc;
this_du->insn = insn;
this_du->cl = cl;
- this_du->need_caller_save_reg = 0;
this_du->earlyclobber = earlyclobber;
- open_chains = this_du;
}
return;
}
for (p = &open_chains; *p;)
{
- struct du_chain *this_du = *p;
+ struct du_head *head = *p;
/* Check if the chain has been terminated if it has then skip to
the next chain.
the chain in Step 3, but are trying to hide in-out operands
from terminate_write in Step 5. */
- if (*this_du->loc == cc0_rtx)
- p = &this_du->next_chain;
+ if (head->terminated)
+ p = &head->next_chain;
else
{
- int regno = REGNO (*this_du->loc);
- int nregs = hard_regno_nregs[regno][GET_MODE (*this_du->loc)];
- int exact_match = (regno == this_regno && nregs == this_nregs);
+ int exact_match = (head->regno == this_regno
+ && head->nregs == this_nregs);
- if (regno + nregs <= this_regno
- || this_regno + this_nregs <= regno)
+ if (head->regno + head->nregs <= this_regno
+ || this_regno + this_nregs <= head->regno)
{
- p = &this_du->next_chain;
+ p = &head->next_chain;
continue;
}
be replaced with, terminate the chain. */
if (cl != NO_REGS)
{
+ struct du_chain *this_du;
this_du = XOBNEW (&rename_obstack, struct du_chain);
this_du->next_use = 0;
- this_du->next_chain = (*p)->next_chain;
this_du->loc = loc;
this_du->insn = insn;
this_du->cl = cl;
- this_du->need_caller_save_reg = 0;
- while (*p)
- p = &(*p)->next_use;
- *p = this_du;
+ head->last->next_use = this_du;
+ head->last = this_du;
return;
}
}
if (action != terminate_overlapping_read || ! exact_match)
{
- struct du_chain *next = this_du->next_chain;
+ struct du_head *next = head->next_chain;
/* Whether the terminated chain can be used for renaming
depends on the action and this being an exact match.
In either case, we remove this element from open_chains. */
+ head->terminated = 1;
if ((action == terminate_dead || action == terminate_write)
&& exact_match)
{
- this_du->next_chain = closed_chains;
- closed_chains = this_du;
+ head->next_chain = closed_chains;
+ closed_chains = head;
if (dump_file)
fprintf (dump_file,
"Closing chain %s at insn %d (%s)\n",
- reg_names[REGNO (*this_du->loc)], INSN_UID (insn),
+ reg_names[head->regno], INSN_UID (insn),
scan_actions_name[(int) action]);
}
else
if (dump_file)
fprintf (dump_file,
"Discarding chain %s at insn %d (%s)\n",
- reg_names[REGNO (*this_du->loc)], INSN_UID (insn),
+ reg_names[head->regno], INSN_UID (insn),
scan_actions_name[(int) action]);
}
*p = next;
}
else
- p = &this_du->next_chain;
+ p = &head->next_chain;
}
}
}
/* Build def/use chain. */
-static struct du_chain *
+static struct du_head *
build_def_use (basic_block bb)
{
rtx insn;
requires a caller-saved reg. */
if (CALL_P (insn))
{
- struct du_chain *p;
+ struct du_head *p;
for (p = open_chains; p; p = p->next_chain)
p->need_caller_save_reg = 1;
}
printed in reverse order as that's how we build them. */
static void
-dump_def_use_chain (struct du_chain *chains)
+dump_def_use_chain (struct du_head *head)
{
- while (chains)
+ while (head)
{
- struct du_chain *this_du = chains;
- int r = REGNO (*this_du->loc);
- int nregs = hard_regno_nregs[r][GET_MODE (*this_du->loc)];
- fprintf (dump_file, "Register %s (%d):", reg_names[r], nregs);
+ struct du_chain *this_du = head->first;
+ fprintf (dump_file, "Register %s (%d):",
+ reg_names[head->regno], head->nregs);
while (this_du)
{
fprintf (dump_file, " %d [%s]", INSN_UID (this_du->insn),
this_du = this_du->next_use;
}
fprintf (dump_file, "\n");
- chains = chains->next_chain;
+ head = head->next_chain;
}
}
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