/* Instruction scheduling pass. This file computes dependencies between
instructions.
Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
Contributed by Michael Tiemann (tiemann@cygnus.com) Enhanced by,
and currently maintained by, Jim Wilson (wilson@cygnus.com)
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
\f
#include "config.h"
#include "system.h"
static bitmap_head *true_dependency_cache;
static bitmap_head *anti_dependency_cache;
static bitmap_head *output_dependency_cache;
-int cache_size;
+static int cache_size;
/* To speed up checking consistency of formed forward insn
dependencies we use the following cache. Another possible solution
#endif
static int deps_may_trap_p (rtx);
-static void add_dependence_list (rtx, rtx, enum reg_note);
-static void add_dependence_list_and_free (rtx, rtx *, enum reg_note);
+static void add_dependence_list (rtx, rtx, int, enum reg_note);
+static void add_dependence_list_and_free (rtx, rtx *, int, enum reg_note);
static void delete_all_dependences (rtx);
static void fixup_sched_groups (rtx);
return 0;
src = SET_SRC (pc_set (insn));
-#if 0
- /* The previous code here was completely invalid and could never extract
- the condition from a jump. This code does the correct thing, but that
- triggers latent bugs later in the scheduler on ports with conditional
- execution. So this is disabled for now. */
+
if (XEXP (src, 2) == pc_rtx)
return XEXP (src, 0);
else if (XEXP (src, 1) == pc_rtx)
return gen_rtx_fmt_ee (revcode, GET_MODE (cond), XEXP (cond, 0),
XEXP (cond, 1));
}
-#endif
return 0;
}
+\f
/* Return nonzero if conditions COND1 and COND2 can never be both true. */
static int
return 1;
return 0;
}
+
+/* Return true if insn1 and insn2 can never depend on one another because
+ the conditions under which they are executed are mutually exclusive. */
+bool
+sched_insns_conditions_mutex_p (rtx insn1, rtx insn2)
+{
+ rtx cond1, cond2;
+
+ /* flow.c doesn't handle conditional lifetimes entirely correctly;
+ calls mess up the conditional lifetimes. */
+ if (!CALL_P (insn1) && !CALL_P (insn2))
+ {
+ cond1 = sched_get_condition (insn1);
+ cond2 = sched_get_condition (insn2);
+ if (cond1 && cond2
+ && conditions_mutex_p (cond1, cond2)
+ /* Make sure first instruction doesn't affect condition of second
+ instruction if switched. */
+ && !modified_in_p (cond1, insn2)
+ /* Make sure second instruction doesn't affect condition of first
+ instruction if switched. */
+ && !modified_in_p (cond2, insn1))
+ return true;
+ }
+ return false;
+}
\f
/* Add ELEM wrapped in an INSN_LIST with reg note kind DEP_TYPE to the
LOG_LINKS of INSN, if not already there. DEP_TYPE indicates the
{
rtx link;
int present_p;
- rtx cond1, cond2;
/* Don't depend an insn on itself. */
if (insn == elem)
if (NOTE_P (elem))
return 0;
- /* flow.c doesn't handle conditional lifetimes entirely correctly;
- calls mess up the conditional lifetimes. */
- /* ??? add_dependence is the wrong place to be eliding dependencies,
- as that forgets that the condition expressions themselves may
- be dependent. */
- if (!CALL_P (insn) && !CALL_P (elem))
- {
- cond1 = sched_get_condition (insn);
- cond2 = sched_get_condition (elem);
- if (cond1 && cond2
- && conditions_mutex_p (cond1, cond2)
- /* Make sure first instruction doesn't affect condition of second
- instruction if switched. */
- && !modified_in_p (cond1, elem)
- /* Make sure second instruction doesn't affect condition of first
- instruction if switched. */
- && !modified_in_p (cond2, insn))
- return 0;
- }
-
present_p = 1;
#ifdef INSN_SCHEDULING
/* ??? No good way to tell from here whether we're doing interblock
/* A convenience wrapper to operate on an entire list. */
static void
-add_dependence_list (rtx insn, rtx list, enum reg_note dep_type)
+add_dependence_list (rtx insn, rtx list, int uncond, enum reg_note dep_type)
{
for (; list; list = XEXP (list, 1))
- add_dependence (insn, XEXP (list, 0), dep_type);
+ {
+ if (uncond || ! sched_insns_conditions_mutex_p (insn, XEXP (list, 0)))
+ add_dependence (insn, XEXP (list, 0), dep_type);
+ }
}
/* Similar, but free *LISTP at the same time. */
static void
-add_dependence_list_and_free (rtx insn, rtx *listp, enum reg_note dep_type)
+add_dependence_list_and_free (rtx insn, rtx *listp, int uncond,
+ enum reg_note dep_type)
{
rtx list, next;
for (list = *listp, *listp = NULL; list ; list = next)
{
next = XEXP (list, 1);
- add_dependence (insn, XEXP (list, 0), dep_type);
+ if (uncond || ! sched_insns_conditions_mutex_p (insn, XEXP (list, 0)))
+ add_dependence (insn, XEXP (list, 0), dep_type);
free_INSN_LIST_node (list);
}
}
static void
fixup_sched_groups (rtx insn)
{
- rtx link;
+ rtx link, prev_nonnote;
for (link = LOG_LINKS (insn); link ; link = XEXP (link, 1))
{
if (XEXP (link, 0) == i)
goto next_link;
} while (SCHED_GROUP_P (i));
- add_dependence (i, XEXP (link, 0), REG_NOTE_KIND (link));
+ if (! sched_insns_conditions_mutex_p (i, XEXP (link, 0)))
+ add_dependence (i, XEXP (link, 0), REG_NOTE_KIND (link));
next_link:;
}
delete_all_dependences (insn);
- if (BLOCK_FOR_INSN (insn) == BLOCK_FOR_INSN (prev_nonnote_insn (insn)))
- add_dependence (insn, prev_nonnote_insn (insn), REG_DEP_ANTI);
+ prev_nonnote = prev_nonnote_insn (insn);
+ if (BLOCK_FOR_INSN (insn) == BLOCK_FOR_INSN (prev_nonnote)
+ && ! sched_insns_conditions_mutex_p (insn, prev_nonnote))
+ add_dependence (insn, prev_nonnote, REG_DEP_ANTI);
}
\f
/* Process an insn's memory dependencies. There are four kinds of
{
if (for_write)
{
- add_dependence_list_and_free (insn, &deps->pending_read_insns,
+ add_dependence_list_and_free (insn, &deps->pending_read_insns, 0,
REG_DEP_ANTI);
free_EXPR_LIST_list (&deps->pending_read_mems);
}
- add_dependence_list_and_free (insn, &deps->pending_write_insns,
+ add_dependence_list_and_free (insn, &deps->pending_write_insns, 0,
for_read ? REG_DEP_ANTI : REG_DEP_OUTPUT);
free_EXPR_LIST_list (&deps->pending_write_mems);
deps->pending_lists_length = 0;
- add_dependence_list_and_free (insn, &deps->last_pending_memory_flush,
+ add_dependence_list_and_free (insn, &deps->last_pending_memory_flush, 1,
for_read ? REG_DEP_ANTI : REG_DEP_OUTPUT);
deps->last_pending_memory_flush = alloc_INSN_LIST (insn, NULL_RTX);
deps->pending_flush_length = 1;
{
regno = REGNO (dest);
+#ifdef STACK_REGS
+ /* Treat all writes to a stack register as modifying the TOS. */
+ if (regno >= FIRST_STACK_REG && regno <= LAST_STACK_REG)
+ {
+ SET_REGNO_REG_SET (reg_pending_uses, FIRST_STACK_REG);
+ regno = FIRST_STACK_REG;
+ }
+#endif
+
/* A hard reg in a wide mode may really be multiple registers.
If so, mark all of them just like the first. */
if (regno < FIRST_PSEUDO_REGISTER)
/* Don't let it cross a call after scheduling if it doesn't
already cross one. */
if (REG_N_CALLS_CROSSED (regno) == 0)
- add_dependence_list (insn, deps->last_function_call, REG_DEP_ANTI);
+ add_dependence_list (insn, deps->last_function_call, 1,
+ REG_DEP_ANTI);
}
}
else if (MEM_P (dest))
pending_mem = deps->pending_read_mems;
while (pending)
{
- if (anti_dependence (XEXP (pending_mem, 0), t))
+ if (anti_dependence (XEXP (pending_mem, 0), t)
+ && ! sched_insns_conditions_mutex_p (insn, XEXP (pending, 0)))
add_dependence (insn, XEXP (pending, 0), REG_DEP_ANTI);
pending = XEXP (pending, 1);
pending_mem = deps->pending_write_mems;
while (pending)
{
- if (output_dependence (XEXP (pending_mem, 0), t))
+ if (output_dependence (XEXP (pending_mem, 0), t)
+ && ! sched_insns_conditions_mutex_p (insn, XEXP (pending, 0)))
add_dependence (insn, XEXP (pending, 0), REG_DEP_OUTPUT);
pending = XEXP (pending, 1);
pending_mem = XEXP (pending_mem, 1);
}
- add_dependence_list (insn, deps->last_pending_memory_flush,
+ add_dependence_list (insn, deps->last_pending_memory_flush, 1,
REG_DEP_ANTI);
add_insn_mem_dependence (deps, &deps->pending_write_insns,
case REG:
{
int regno = REGNO (x);
+
+#ifdef STACK_REGS
+ /* Treat all reads of a stack register as modifying the TOS. */
+ if (regno >= FIRST_STACK_REG && regno <= LAST_STACK_REG)
+ {
+ SET_REGNO_REG_SET (reg_pending_sets, FIRST_STACK_REG);
+ regno = FIRST_STACK_REG;
+ }
+#endif
+
if (regno < FIRST_PSEUDO_REGISTER)
{
int i = hard_regno_nregs[regno][GET_MODE (x)];
pending_mem = deps->pending_read_mems;
while (pending)
{
- if (read_dependence (XEXP (pending_mem, 0), t))
+ if (read_dependence (XEXP (pending_mem, 0), t)
+ && ! sched_insns_conditions_mutex_p (insn, XEXP (pending, 0)))
add_dependence (insn, XEXP (pending, 0), REG_DEP_ANTI);
pending = XEXP (pending, 1);
while (pending)
{
if (true_dependence (XEXP (pending_mem, 0), VOIDmode,
- t, rtx_varies_p))
- add_dependence (insn, XEXP (pending, 0), 0);
+ t, rtx_varies_p)
+ && ! sched_insns_conditions_mutex_p (insn, XEXP (pending, 0)))
+ add_dependence (insn, XEXP (pending, 0), REG_DEP_TRUE);
pending = XEXP (pending, 1);
pending_mem = XEXP (pending_mem, 1);
}
for (u = deps->last_pending_memory_flush; u; u = XEXP (u, 1))
- if (!JUMP_P (XEXP (u, 0))
- || deps_may_trap_p (x))
+ if (! JUMP_P (XEXP (u, 0)) || deps_may_trap_p (x))
add_dependence (insn, XEXP (u, 0), REG_DEP_ANTI);
/* Always add these dependencies to pending_reads, since
and others know that a value is dead. Depend on the last call
instruction so that reg-stack won't get confused. */
if (code == CLOBBER)
- add_dependence_list (insn, deps->last_function_call, REG_DEP_OUTPUT);
+ add_dependence_list (insn, deps->last_function_call, 1, REG_DEP_OUTPUT);
}
else if (code == PARALLEL)
{
EXECUTE_IF_SET_IN_REG_SET (&tmp_uses, 0, i, rsi)
{
struct deps_reg *reg_last = &deps->reg_last[i];
- add_dependence_list (insn, reg_last->sets, REG_DEP_ANTI);
- add_dependence_list (insn, reg_last->clobbers, REG_DEP_ANTI);
+ add_dependence_list (insn, reg_last->sets, 0, REG_DEP_ANTI);
+ add_dependence_list (insn, reg_last->clobbers, 0, REG_DEP_ANTI);
reg_last->uses_length++;
reg_last->uses = alloc_INSN_LIST (insn, reg_last->uses);
}
pending_mem = deps->pending_write_mems;
while (pending)
{
- add_dependence (insn, XEXP (pending, 0), REG_DEP_OUTPUT);
+ if (! sched_insns_conditions_mutex_p (insn, XEXP (pending, 0)))
+ add_dependence (insn, XEXP (pending, 0), REG_DEP_OUTPUT);
pending = XEXP (pending, 1);
pending_mem = XEXP (pending_mem, 1);
}
pending_mem = deps->pending_read_mems;
while (pending)
{
- if (MEM_VOLATILE_P (XEXP (pending_mem, 0)))
+ if (MEM_VOLATILE_P (XEXP (pending_mem, 0))
+ && ! sched_insns_conditions_mutex_p (insn, XEXP (pending, 0)))
add_dependence (insn, XEXP (pending, 0), REG_DEP_OUTPUT);
pending = XEXP (pending, 1);
pending_mem = XEXP (pending_mem, 1);
}
- add_dependence_list (insn, deps->last_pending_memory_flush,
+ add_dependence_list (insn, deps->last_pending_memory_flush, 1,
REG_DEP_ANTI);
}
}
{
/* In the case of barrier the most added dependencies are not
real, so we use anti-dependence here. */
- if (GET_CODE (PATTERN (insn)) == COND_EXEC)
+ if (sched_get_condition (insn))
{
EXECUTE_IF_SET_IN_REG_SET (&deps->reg_last_in_use, 0, i, rsi)
{
struct deps_reg *reg_last = &deps->reg_last[i];
- add_dependence_list (insn, reg_last->uses, REG_DEP_ANTI);
+ add_dependence_list (insn, reg_last->uses, 0, REG_DEP_ANTI);
add_dependence_list
- (insn, reg_last->sets,
- reg_pending_barrier == TRUE_BARRIER ? 0 : REG_DEP_ANTI);
+ (insn, reg_last->sets, 0,
+ reg_pending_barrier == TRUE_BARRIER ? REG_DEP_TRUE : REG_DEP_ANTI);
add_dependence_list
- (insn, reg_last->clobbers,
- reg_pending_barrier == TRUE_BARRIER ? 0 : REG_DEP_ANTI);
+ (insn, reg_last->clobbers, 0,
+ reg_pending_barrier == TRUE_BARRIER ? REG_DEP_TRUE : REG_DEP_ANTI);
}
}
else
EXECUTE_IF_SET_IN_REG_SET (&deps->reg_last_in_use, 0, i, rsi)
{
struct deps_reg *reg_last = &deps->reg_last[i];
- add_dependence_list_and_free (insn, ®_last->uses,
+ add_dependence_list_and_free (insn, ®_last->uses, 0,
REG_DEP_ANTI);
add_dependence_list_and_free
- (insn, ®_last->sets,
- reg_pending_barrier == TRUE_BARRIER ? 0 : REG_DEP_ANTI);
+ (insn, ®_last->sets, 0,
+ reg_pending_barrier == TRUE_BARRIER ? REG_DEP_TRUE : REG_DEP_ANTI);
add_dependence_list_and_free
- (insn, ®_last->clobbers,
- reg_pending_barrier == TRUE_BARRIER ? 0 : REG_DEP_ANTI);
+ (insn, ®_last->clobbers, 0,
+ reg_pending_barrier == TRUE_BARRIER ? REG_DEP_TRUE : REG_DEP_ANTI);
reg_last->uses_length = 0;
reg_last->clobbers_length = 0;
}
{
/* If the current insn is conditional, we can't free any
of the lists. */
- if (GET_CODE (PATTERN (insn)) == COND_EXEC)
+ if (sched_get_condition (insn))
{
EXECUTE_IF_SET_IN_REG_SET (reg_pending_uses, 0, i, rsi)
{
struct deps_reg *reg_last = &deps->reg_last[i];
- add_dependence_list (insn, reg_last->sets, 0);
- add_dependence_list (insn, reg_last->clobbers, 0);
+ add_dependence_list (insn, reg_last->sets, 0, REG_DEP_TRUE);
+ add_dependence_list (insn, reg_last->clobbers, 0, REG_DEP_TRUE);
reg_last->uses = alloc_INSN_LIST (insn, reg_last->uses);
reg_last->uses_length++;
}
EXECUTE_IF_SET_IN_REG_SET (reg_pending_clobbers, 0, i, rsi)
{
struct deps_reg *reg_last = &deps->reg_last[i];
- add_dependence_list (insn, reg_last->sets, REG_DEP_OUTPUT);
- add_dependence_list (insn, reg_last->uses, REG_DEP_ANTI);
+ add_dependence_list (insn, reg_last->sets, 0, REG_DEP_OUTPUT);
+ add_dependence_list (insn, reg_last->uses, 0, REG_DEP_ANTI);
reg_last->clobbers = alloc_INSN_LIST (insn, reg_last->clobbers);
reg_last->clobbers_length++;
}
EXECUTE_IF_SET_IN_REG_SET (reg_pending_sets, 0, i, rsi)
{
struct deps_reg *reg_last = &deps->reg_last[i];
- add_dependence_list (insn, reg_last->sets, REG_DEP_OUTPUT);
- add_dependence_list (insn, reg_last->clobbers, REG_DEP_OUTPUT);
- add_dependence_list (insn, reg_last->uses, REG_DEP_ANTI);
+ add_dependence_list (insn, reg_last->sets, 0, REG_DEP_OUTPUT);
+ add_dependence_list (insn, reg_last->clobbers, 0, REG_DEP_OUTPUT);
+ add_dependence_list (insn, reg_last->uses, 0, REG_DEP_ANTI);
reg_last->sets = alloc_INSN_LIST (insn, reg_last->sets);
SET_REGNO_REG_SET (&deps->reg_conditional_sets, i);
}
EXECUTE_IF_SET_IN_REG_SET (reg_pending_uses, 0, i, rsi)
{
struct deps_reg *reg_last = &deps->reg_last[i];
- add_dependence_list (insn, reg_last->sets, 0);
- add_dependence_list (insn, reg_last->clobbers, 0);
+ add_dependence_list (insn, reg_last->sets, 0, REG_DEP_TRUE);
+ add_dependence_list (insn, reg_last->clobbers, 0, REG_DEP_TRUE);
reg_last->uses_length++;
reg_last->uses = alloc_INSN_LIST (insn, reg_last->uses);
}
if (reg_last->uses_length > MAX_PENDING_LIST_LENGTH
|| reg_last->clobbers_length > MAX_PENDING_LIST_LENGTH)
{
- add_dependence_list_and_free (insn, ®_last->sets,
+ add_dependence_list_and_free (insn, ®_last->sets, 0,
REG_DEP_OUTPUT);
- add_dependence_list_and_free (insn, ®_last->uses,
+ add_dependence_list_and_free (insn, ®_last->uses, 0,
REG_DEP_ANTI);
- add_dependence_list_and_free (insn, ®_last->clobbers,
+ add_dependence_list_and_free (insn, ®_last->clobbers, 0,
REG_DEP_OUTPUT);
reg_last->sets = alloc_INSN_LIST (insn, reg_last->sets);
reg_last->clobbers_length = 0;
}
else
{
- add_dependence_list (insn, reg_last->sets, REG_DEP_OUTPUT);
- add_dependence_list (insn, reg_last->uses, REG_DEP_ANTI);
+ add_dependence_list (insn, reg_last->sets, 0, REG_DEP_OUTPUT);
+ add_dependence_list (insn, reg_last->uses, 0, REG_DEP_ANTI);
}
reg_last->clobbers_length++;
reg_last->clobbers = alloc_INSN_LIST (insn, reg_last->clobbers);
EXECUTE_IF_SET_IN_REG_SET (reg_pending_sets, 0, i, rsi)
{
struct deps_reg *reg_last = &deps->reg_last[i];
- add_dependence_list_and_free (insn, ®_last->sets,
+ add_dependence_list_and_free (insn, ®_last->sets, 0,
REG_DEP_OUTPUT);
- add_dependence_list_and_free (insn, ®_last->clobbers,
+ add_dependence_list_and_free (insn, ®_last->clobbers, 0,
REG_DEP_OUTPUT);
- add_dependence_list_and_free (insn, ®_last->uses,
+ add_dependence_list_and_free (insn, ®_last->uses, 0,
REG_DEP_ANTI);
reg_last->sets = alloc_INSN_LIST (insn, reg_last->sets);
reg_last->uses_length = 0;
/* For each insn which shouldn't cross a call, add a dependence
between that insn and this call insn. */
- add_dependence_list_and_free (insn, &deps->sched_before_next_call,
+ add_dependence_list_and_free (insn, &deps->sched_before_next_call, 1,
REG_DEP_ANTI);
sched_analyze_insn (deps, PATTERN (insn), insn, loop_notes);