/* Standard problems for dataflow support routines.
Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
- 2008, 2009, 2010 Free Software Foundation, Inc.
+ 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
Originally contributed by Michael P. Hayes
(m.hayes@elec.canterbury.ac.nz, mhayes@redhat.com)
Major rewrite contributed by Danny Berlin (dberlin@dberlin.org)
#include "recog.h"
#include "function.h"
#include "regs.h"
-#include "output.h"
#include "alloc-pool.h"
#include "flags.h"
#include "hard-reg-set.h"
blocks within infinite loops. */
if (!reload_completed)
{
+ unsigned int pic_offset_table_regnum = PIC_OFFSET_TABLE_REGNUM;
/* Any reference to any pseudo before reload is a potential
reference of the frame pointer. */
bitmap_set_bit (&df->hardware_regs_used, FRAME_POINTER_REGNUM);
/* Any constant, or pseudo with constant equivalences, may
require reloading from memory using the pic register. */
- if ((unsigned) PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM
- && fixed_regs[PIC_OFFSET_TABLE_REGNUM])
- bitmap_set_bit (&df->hardware_regs_used, PIC_OFFSET_TABLE_REGNUM);
+ if (pic_offset_table_regnum != INVALID_REGNUM
+ && fixed_regs[pic_offset_table_regnum])
+ bitmap_set_bit (&df->hardware_regs_used, pic_offset_table_regnum);
}
EXECUTE_IF_SET_IN_BITMAP (df_lr->out_of_date_transfer_functions, 0, bb_index, bi)
/* Remove all of the REG_DEAD or REG_UNUSED notes from INSN and add
- them to OLD_DEAD_NOTES and OLD_UNUSED_NOTES. */
+ them to OLD_DEAD_NOTES and OLD_UNUSED_NOTES. Remove also
+ REG_EQUAL/REG_EQUIV notes referring to dead pseudos using LIVE
+ as the bitmap of currently live registers. */
static void
-df_kill_notes (rtx insn)
+df_kill_notes (rtx insn, bitmap live)
{
rtx *pprev = ®_NOTES (insn);
rtx link = *pprev;
}
break;
+ case REG_EQUAL:
+ case REG_EQUIV:
+ {
+ /* Remove the notes that refer to dead registers. As we have at most
+ one REG_EQUAL/EQUIV note, all of EQ_USES will refer to this note
+ so we need to purge the complete EQ_USES vector when removing
+ the note using df_notes_rescan. */
+ df_ref *use_rec;
+ bool deleted = false;
+
+ for (use_rec = DF_INSN_EQ_USES (insn); *use_rec; use_rec++)
+ {
+ df_ref use = *use_rec;
+ if (DF_REF_REGNO (use) > FIRST_PSEUDO_REGISTER
+ && DF_REF_LOC (use)
+ && (DF_REF_FLAGS (use) & DF_REF_IN_NOTE)
+ && ! bitmap_bit_p (live, DF_REF_REGNO (use))
+ && loc_mentioned_in_p (DF_REF_LOC (use), XEXP (link, 0)))
+ {
+ deleted = true;
+ break;
+ }
+ }
+ if (deleted)
+ {
+ rtx next;
+#ifdef REG_DEAD_DEBUGGING
+ df_print_note ("deleting: ", insn, link);
+#endif
+ next = XEXP (link, 1);
+ free_EXPR_LIST_node (link);
+ *pprev = link = next;
+ df_notes_rescan (insn);
+ }
+ else
+ {
+ pprev = &XEXP (link, 1);
+ link = *pprev;
+ }
+ break;
+ }
default:
pprev = &XEXP (link, 1);
link = *pprev;
}
-/* Node of a linked list of uses of dead REGs in debug insns. */
-struct dead_debug_use
-{
- df_ref use;
- struct dead_debug_use *next;
-};
-
-/* Linked list of the above, with a bitmap of the REGs in the
- list. */
-struct dead_debug
-{
- struct dead_debug_use *head;
- bitmap used;
- bitmap to_rescan;
-};
-
-static void dead_debug_reset (struct dead_debug *, unsigned int);
-
-
/* Set the REG_UNUSED notes for the multiword hardreg defs in INSN
based on the bits in LIVE. Do not generate notes for registers in
artificial uses. DO_NOT_GEN is updated so that REG_DEAD notes are
{
unsigned int regno = mws->start_regno;
df_set_note (REG_UNUSED, insn, mws->mw_reg);
- dead_debug_reset (debug, regno);
+ dead_debug_insert_temp (debug, regno, insn, DEBUG_TEMP_AFTER_WITH_REG);
#ifdef REG_DEAD_DEBUGGING
df_print_note ("adding 1: ", insn, REG_NOTES (insn));
&& !bitmap_bit_p (artificial_uses, r))
{
df_set_note (REG_UNUSED, insn, regno_reg_rtx[r]);
- dead_debug_reset (debug, r);
+ dead_debug_insert_temp (debug, r, insn, DEBUG_TEMP_AFTER_WITH_REG);
#ifdef REG_DEAD_DEBUGGING
df_print_note ("adding 2: ", insn, REG_NOTES (insn));
#endif
if (df_whole_mw_reg_dead_p (mws, live, artificial_uses, do_not_gen))
{
- /* Add a dead note for the entire multi word register. */
if (is_debug)
{
*added_notes_p = true;
return;
}
+ /* Add a dead note for the entire multi word register. */
df_set_note (REG_DEAD, insn, mws->mw_reg);
#ifdef REG_DEAD_DEBUGGING
df_print_note ("adding 1: ", insn, REG_NOTES (insn));
rtx reg = (DF_REF_LOC (def))
? *DF_REF_REAL_LOC (def): DF_REF_REG (def);
df_set_note (REG_UNUSED, insn, reg);
- dead_debug_reset (debug, dregno);
+ dead_debug_insert_temp (debug, dregno, insn, DEBUG_TEMP_AFTER_WITH_REG);
#ifdef REG_DEAD_DEBUGGING
df_print_note ("adding 3: ", insn, REG_NOTES (insn));
#endif
/* Initialize DEBUG to an empty list, and clear USED, if given. */
-static inline void
+void
dead_debug_init (struct dead_debug *debug, bitmap used)
{
debug->head = NULL;
bitmap_clear (used);
}
-/* Reset all debug insns with pending uses. Release the bitmap in it,
- unless it is USED. USED must be the same bitmap passed to
- dead_debug_init. */
-static inline void
-dead_debug_finish (struct dead_debug *debug, bitmap used)
+/* Reset all debug uses in HEAD, and clear DEBUG->to_rescan bits of
+ each reset insn. DEBUG is not otherwise modified. If HEAD is
+ DEBUG->head, DEBUG->head will be set to NULL at the end.
+ Otherwise, entries from DEBUG->head that pertain to reset insns
+ will be removed, and only then rescanned. */
+
+static void
+dead_debug_reset_uses (struct dead_debug *debug, struct dead_debug_use *head)
{
- struct dead_debug_use *head;
- rtx insn = NULL;
+ bool got_head = (debug->head == head);
+ bitmap rescan;
+ struct dead_debug_use **tailp = &debug->head;
+ struct dead_debug_use *cur;
+ bitmap_iterator bi;
+ unsigned int uid;
- if (debug->used != used)
- BITMAP_FREE (debug->used);
+ if (got_head)
+ rescan = NULL;
+ else
+ rescan = BITMAP_ALLOC (NULL);
- while ((head = debug->head))
+ while (head)
{
+ struct dead_debug_use *next = head->next;
+ rtx insn;
+
insn = DF_REF_INSN (head->use);
- if (!head->next || DF_REF_INSN (head->next->use) != insn)
+ if (!next || DF_REF_INSN (next->use) != insn)
{
INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC ();
- df_insn_rescan_debug_internal (insn);
+ if (got_head)
+ df_insn_rescan_debug_internal (insn);
+ else
+ bitmap_set_bit (rescan, INSN_UID (insn));
if (debug->to_rescan)
bitmap_clear_bit (debug->to_rescan, INSN_UID (insn));
}
- debug->head = head->next;
XDELETE (head);
+ head = next;
+ }
+
+ if (got_head)
+ {
+ debug->head = NULL;
+ return;
}
+ while ((cur = *tailp))
+ if (bitmap_bit_p (rescan, INSN_UID (DF_REF_INSN (cur->use))))
+ {
+ *tailp = cur->next;
+ XDELETE (cur);
+ }
+ else
+ tailp = &cur->next;
+
+ EXECUTE_IF_SET_IN_BITMAP (rescan, 0, uid, bi)
+ {
+ struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
+ if (insn_info)
+ df_insn_rescan_debug_internal (insn_info->insn);
+ }
+
+ BITMAP_FREE (rescan);
+}
+
+/* Reset all debug insns with pending uses. Release the bitmap in it,
+ unless it is USED. USED must be the same bitmap passed to
+ dead_debug_init. */
+void
+dead_debug_finish (struct dead_debug *debug, bitmap used)
+{
+ if (debug->used != used)
+ BITMAP_FREE (debug->used);
+
+ dead_debug_reset_uses (debug, debug->head);
+
if (debug->to_rescan)
{
bitmap_iterator bi;
}
}
-/* Reset DEBUG_INSNs with pending uses of DREGNO. */
-static void
-dead_debug_reset (struct dead_debug *debug, unsigned int dregno)
-{
- struct dead_debug_use **tailp = &debug->head;
- struct dead_debug_use *cur;
- rtx insn;
-
- if (!debug->used || !bitmap_clear_bit (debug->used, dregno))
- return;
-
- while ((cur = *tailp))
- {
- if (DF_REF_REGNO (cur->use) == dregno)
- {
- *tailp = cur->next;
- insn = DF_REF_INSN (cur->use);
- INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC ();
- if (debug->to_rescan == NULL)
- debug->to_rescan = BITMAP_ALLOC (NULL);
- bitmap_set_bit (debug->to_rescan, INSN_UID (insn));
- XDELETE (cur);
- }
- else
- tailp = &(*tailp)->next;
- }
-}
-
/* Add USE to DEBUG. It must be a dead reference to UREGNO in a debug
insn. Create a bitmap for DEBUG as needed. */
-static inline void
+void
dead_debug_add (struct dead_debug *debug, df_ref use, unsigned int uregno)
{
struct dead_debug_use *newddu = XNEW (struct dead_debug_use);
if (!debug->used)
debug->used = BITMAP_ALLOC (NULL);
+ /* ??? If we dealt with split multi-registers below, we should set
+ all registers for the used mode in case of hardware
+ registers. */
bitmap_set_bit (debug->used, uregno);
}
/* If UREGNO is referenced by any entry in DEBUG, emit a debug insn
- before INSN that binds the REG to a debug temp, and replace all
- uses of UREGNO in DEBUG with uses of the debug temp. INSN must be
- the insn where UREGNO dies. */
-static inline void
-dead_debug_insert_before (struct dead_debug *debug, unsigned int uregno,
- rtx insn)
+ before or after INSN (depending on WHERE), that binds a debug temp
+ to the widest-mode use of UREGNO, if WHERE is *_WITH_REG, or the
+ value stored in UREGNO by INSN otherwise, and replace all uses of
+ UREGNO in DEBUG with uses of the debug temp. INSN must be where
+ UREGNO dies, if WHERE is *_BEFORE_*, or where it is set otherwise.
+ Return the number of debug insns emitted. */
+int
+dead_debug_insert_temp (struct dead_debug *debug, unsigned int uregno,
+ rtx insn, enum debug_temp_where where)
{
struct dead_debug_use **tailp = &debug->head;
struct dead_debug_use *cur;
struct dead_debug_use *uses = NULL;
struct dead_debug_use **usesp = &uses;
rtx reg = NULL;
+ rtx breg;
rtx dval;
rtx bind;
if (!debug->used || !bitmap_clear_bit (debug->used, uregno))
- return;
+ return 0;
/* Move all uses of uregno from debug->head to uses, setting mode to
the widest referenced mode. */
tailp = &(*tailp)->next;
}
- gcc_assert (reg);
+ /* We may have dangling bits in debug->used for registers that were part
+ of a multi-register use, one component of which has been reset. */
+ if (reg == NULL)
+ {
+ gcc_checking_assert (!uses);
+ return 0;
+ }
+
+ gcc_checking_assert (uses);
+
+ breg = reg;
+ /* Recover the expression INSN stores in REG. */
+ if (where == DEBUG_TEMP_BEFORE_WITH_VALUE)
+ {
+ rtx set = single_set (insn);
+ rtx dest, src;
+
+ if (set)
+ {
+ dest = SET_DEST (set);
+ src = SET_SRC (set);
+ /* Lose if the REG-setting insn is a CALL. */
+ if (GET_CODE (src) == CALL)
+ {
+ while (uses)
+ {
+ cur = uses->next;
+ XDELETE (uses);
+ uses = cur;
+ }
+ return 0;
+ }
+ }
+
+ /* ??? Should we try to extract it from a PARALLEL? */
+ if (!set)
+ breg = NULL;
+ /* Cool, it's the same REG, we can use SRC. */
+ else if (dest == reg)
+ breg = copy_rtx (src);
+ else if (REG_P (dest))
+ {
+ /* Hmm... Something's fishy, we should be setting REG here. */
+ if (REGNO (dest) != REGNO (reg))
+ breg = NULL;
+ /* If we're not overwriting all the hardware registers that
+ setting REG in its mode would, we won't know what to bind
+ the debug temp to. ??? We could bind the debug_expr to a
+ CONCAT or PARALLEL with the split multi-registers, and
+ replace them as we found the corresponding sets. */
+ else if (REGNO (reg) < FIRST_PSEUDO_REGISTER
+ && (hard_regno_nregs[REGNO (reg)][GET_MODE (reg)]
+ != hard_regno_nregs[REGNO (reg)][GET_MODE (dest)]))
+ breg = NULL;
+ /* Ok, it's the same (hardware) REG, but with a different
+ mode, so SUBREG it. */
+ else
+ breg = lowpart_subreg (GET_MODE (reg), copy_rtx (src),
+ GET_MODE (dest));
+ }
+ else if (GET_CODE (dest) == SUBREG)
+ {
+ /* We should be setting REG here. Lose. */
+ if (REGNO (SUBREG_REG (dest)) != REGNO (reg))
+ breg = NULL;
+ /* Lose if we're setting something other than the lowpart of
+ REG. */
+ else if (!subreg_lowpart_p (dest))
+ breg = NULL;
+ /* If we're not overwriting all the hardware registers that
+ setting REG in its mode would, we won't know what to bind
+ the debug temp to. */
+ else if (REGNO (reg) < FIRST_PSEUDO_REGISTER
+ && (hard_regno_nregs[REGNO (reg)][GET_MODE (reg)]
+ != hard_regno_nregs[REGNO (reg)][GET_MODE (dest)]))
+ breg = NULL;
+ /* Yay, we can use SRC, just adjust its mode. */
+ else
+ breg = lowpart_subreg (GET_MODE (reg), copy_rtx (src),
+ GET_MODE (dest));
+ }
+ /* Oh well, we're out of luck. */
+ else
+ breg = NULL;
+
+ /* We couldn't figure out the value stored in REG, so reset all
+ of its pending debug uses. */
+ if (!breg)
+ {
+ dead_debug_reset_uses (debug, uses);
+ return 0;
+ }
+ }
+
+ /* If there's a single (debug) use of an otherwise unused REG, and
+ the debug use is not part of a larger expression, then it
+ probably doesn't make sense to introduce a new debug temp. */
+ if (where == DEBUG_TEMP_AFTER_WITH_REG && !uses->next)
+ {
+ rtx next = DF_REF_INSN (uses->use);
+
+ if (DEBUG_INSN_P (next) && reg == INSN_VAR_LOCATION_LOC (next))
+ {
+ XDELETE (uses);
+ return 0;
+ }
+ }
/* Create DEBUG_EXPR (and DEBUG_EXPR_DECL). */
dval = make_debug_expr_from_rtl (reg);
/* Emit a debug bind insn before the insn in which reg dies. */
bind = gen_rtx_VAR_LOCATION (GET_MODE (reg),
- DEBUG_EXPR_TREE_DECL (dval), reg,
+ DEBUG_EXPR_TREE_DECL (dval), breg,
VAR_INIT_STATUS_INITIALIZED);
- bind = emit_debug_insn_before (bind, insn);
+ if (where == DEBUG_TEMP_AFTER_WITH_REG)
+ bind = emit_debug_insn_after (bind, insn);
+ else
+ bind = emit_debug_insn_before (bind, insn);
df_insn_rescan (bind);
/* Adjust all uses. */
uses = cur->next;
XDELETE (cur);
}
+
+ return 1;
}
/* Recompute the REG_DEAD and REG_UNUSED notes and compute register
debug_insn = DEBUG_INSN_P (insn);
bitmap_clear (do_not_gen);
- df_kill_notes (insn);
+ df_kill_notes (insn, live);
/* Process the defs. */
if (CALL_P (insn))
while (*mws_rec)
{
struct df_mw_hardreg *mws = *mws_rec;
- if ((DF_MWS_REG_DEF_P (mws))
+ if (DF_MWS_REG_USE_P (mws)
&& !df_ignore_stack_reg (mws->start_regno))
{
bool really_add_notes = debug_insn != 0;
{
if (debug_insn > 0)
{
- dead_debug_add (&debug, use, uregno);
+ /* We won't add REG_UNUSED or REG_DEAD notes for
+ these, so we don't have to mess with them in
+ debug insns either. */
+ if (!bitmap_bit_p (artificial_uses, uregno)
+ && !df_ignore_stack_reg (uregno))
+ dead_debug_add (&debug, use, uregno);
continue;
}
break;
}
else
- dead_debug_insert_before (&debug, uregno, insn);
+ dead_debug_insert_temp (&debug, uregno, insn,
+ DEBUG_TEMP_BEFORE_WITH_REG);
if ( (!(DF_REF_FLAGS (use)
& (DF_REF_MW_HARDREG | DF_REF_READ_WRITE)))
{
rtx reg = XEXP (link, 0);
int regno = REGNO (reg);
- if (regno < FIRST_PSEUDO_REGISTER)
- {
- int n = hard_regno_nregs[regno][GET_MODE (reg)];
- while (--n >= 0)
- bitmap_clear_bit (live, regno + n);
- }
+ if (HARD_REGISTER_NUM_P (regno))
+ bitmap_clear_range (live, regno,
+ hard_regno_nregs[regno][GET_MODE (reg)]);
else
bitmap_clear_bit (live, regno);
}
if (bitmap_intersect_p (merge_set, test_use)
|| bitmap_intersect_p (merge_use, test_set))
break;
- max_to = insn;
+#ifdef HAVE_cc0
+ if (!sets_cc0_p (insn))
+#endif
+ max_to = insn;
}
next = NEXT_INSN (insn);
if (insn == to)
{
if (NONDEBUG_INSN_P (insn))
{
- if (!bitmap_intersect_p (test_set, local_merge_live))
+ if (!bitmap_intersect_p (test_set, local_merge_live)
+#ifdef HAVE_cc0
+ && !sets_cc0_p (insn)
+#endif
+ )
{
max_to = insn;
break;
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