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-rw-r--r--gcc/ChangeLog16
-rw-r--r--gcc/combine-stack-adj.c136
-rw-r--r--gcc/postreload.c19
3 files changed, 154 insertions, 17 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6186c07..b1c0759 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,19 @@
+2020-05-05 Jakub Jelinek <jakub@redhat.com>
+
+ PR rtl-optimization/94516
+ * postreload.c (reload_cse_simplify): When replacing sp = sp + const
+ with sp = reg, add REG_EQUAL note with sp + const.
+ * combine-stack-adj.c (try_apply_stack_adjustment): Change return
+ type from int to bool. Add LIVE and OTHER_INSN arguments. Undo
+ postreload sp = sp + const to sp = reg optimization if needed and
+ possible.
+ (combine_stack_adjustments_for_block): Add LIVE argument. Handle
+ reg = sp insn with sp + const REG_EQUAL note. Adjust
+ try_apply_stack_adjustment caller, call
+ df_simulate_initialize_forwards and df_simulate_one_insn_forwards.
+ (combine_stack_adjustments): Allocate and free LIVE bitmap,
+ adjust combine_stack_adjustments_for_block caller.
+
2020-05-05 Martin Liska <mliska@suse.cz>
PR gcov-profile/93623
diff --git a/gcc/combine-stack-adj.c b/gcc/combine-stack-adj.c
index 073b7f0..281166b 100644
--- a/gcc/combine-stack-adj.c
+++ b/gcc/combine-stack-adj.c
@@ -70,9 +70,10 @@ static rtx single_set_for_csa (rtx_insn *);
static void free_csa_reflist (struct csa_reflist *);
static struct csa_reflist *record_one_stack_ref (rtx_insn *, rtx *,
struct csa_reflist *);
-static int try_apply_stack_adjustment (rtx_insn *, struct csa_reflist *,
- HOST_WIDE_INT, HOST_WIDE_INT);
-static void combine_stack_adjustments_for_block (basic_block);
+static bool try_apply_stack_adjustment (rtx_insn *, struct csa_reflist *,
+ HOST_WIDE_INT, HOST_WIDE_INT,
+ bitmap, rtx_insn *);
+static void combine_stack_adjustments_for_block (basic_block, bitmap);
/* Main entry point for stack adjustment combination. */
@@ -81,9 +82,12 @@ static void
combine_stack_adjustments (void)
{
basic_block bb;
+ bitmap live = BITMAP_ALLOC (&reg_obstack);
FOR_EACH_BB_FN (bb, cfun)
- combine_stack_adjustments_for_block (bb);
+ combine_stack_adjustments_for_block (bb, live);
+
+ BITMAP_FREE (live);
}
/* Recognize a MEM of the form (sp) or (plus sp const). */
@@ -219,18 +223,60 @@ no_unhandled_cfa (rtx_insn *insn)
as each of the memories and stack references in REFLIST. Return true
on success. */
-static int
+static bool
try_apply_stack_adjustment (rtx_insn *insn, struct csa_reflist *reflist,
- HOST_WIDE_INT new_adjust, HOST_WIDE_INT delta)
+ HOST_WIDE_INT new_adjust, HOST_WIDE_INT delta,
+ bitmap live, rtx_insn *other_insn)
{
struct csa_reflist *ml;
rtx set;
+ bool remove_equal = false;
set = single_set_for_csa (insn);
if (MEM_P (SET_DEST (set)))
validate_change (insn, &SET_DEST (set),
replace_equiv_address (SET_DEST (set), stack_pointer_rtx),
1);
+ else if (REG_P (SET_SRC (set)))
+ {
+ if (other_insn == NULL_RTX || live == NULL)
+ return false;
+ rtx other_set = single_set_for_csa (other_insn);
+ if (SET_DEST (other_set) != stack_pointer_rtx
+ || GET_CODE (SET_SRC (other_set)) != PLUS
+ || XEXP (SET_SRC (other_set), 0) != stack_pointer_rtx
+ || !CONST_INT_P (XEXP (SET_SRC (other_set), 1)))
+ return false;
+ if (PATTERN (other_insn) != other_set)
+ {
+ if (GET_CODE (PATTERN (other_insn)) != PARALLEL)
+ return false;
+ int i;
+ rtx p = PATTERN (other_insn);
+ for (i = 0; i < XVECLEN (p, 0); ++i)
+ {
+ rtx this_rtx = XVECEXP (p, 0, i);
+ if (this_rtx == other_set)
+ continue;
+ if (GET_CODE (this_rtx) != CLOBBER)
+ return false;
+ if (!REG_P (XEXP (this_rtx, 0))
+ || !HARD_REGISTER_P (XEXP (this_rtx, 0)))
+ return false;
+ unsigned int end_regno = END_REGNO (XEXP (this_rtx, 0));
+ for (unsigned int regno = REGNO (XEXP (this_rtx, 0));
+ regno < end_regno; ++regno)
+ if (bitmap_bit_p (live, regno))
+ return false;
+ }
+ }
+ validate_change (insn, &PATTERN (insn), copy_rtx (PATTERN (other_insn)),
+ 1);
+ set = single_set_for_csa (insn);
+ validate_change (insn, &XEXP (SET_SRC (set), 1), GEN_INT (new_adjust),
+ 1);
+ remove_equal = true;
+ }
else
validate_change (insn, &XEXP (SET_SRC (set), 1), GEN_INT (new_adjust), 1);
@@ -256,10 +302,12 @@ try_apply_stack_adjustment (rtx_insn *insn, struct csa_reflist *reflist,
for (ml = reflist; ml ; ml = ml->next)
ml->sp_offset -= delta;
- return 1;
+ if (remove_equal)
+ remove_reg_equal_equiv_notes (insn);
+ return true;
}
else
- return 0;
+ return false;
}
/* For non-debug insns, record all stack memory references in INSN
@@ -489,16 +537,21 @@ force_move_args_size_note (basic_block bb, rtx_insn *prev, rtx_insn *insn)
/* Subroutine of combine_stack_adjustments, called for each basic block. */
static void
-combine_stack_adjustments_for_block (basic_block bb)
+combine_stack_adjustments_for_block (basic_block bb, bitmap live)
{
HOST_WIDE_INT last_sp_adjust = 0;
rtx_insn *last_sp_set = NULL;
rtx_insn *last2_sp_set = NULL;
+ bitmap last_sp_live = NULL;
struct csa_reflist *reflist = NULL;
+ bitmap copy = NULL;
rtx_insn *insn, *next;
rtx set;
bool end_of_block = false;
+ bitmap_copy (live, DF_LR_IN (bb));
+ df_simulate_initialize_forwards (bb, live);
+
for (insn = BB_HEAD (bb); !end_of_block ; insn = next)
{
end_of_block = insn == BB_END (bb);
@@ -514,21 +567,43 @@ combine_stack_adjustments_for_block (basic_block bb)
{
rtx dest = SET_DEST (set);
rtx src = SET_SRC (set);
+ HOST_WIDE_INT this_adjust = 0;
/* Find constant additions to the stack pointer. */
if (dest == stack_pointer_rtx
&& GET_CODE (src) == PLUS
&& XEXP (src, 0) == stack_pointer_rtx
&& CONST_INT_P (XEXP (src, 1)))
+ this_adjust = INTVAL (XEXP (src, 1));
+ /* Or such additions turned by postreload into a store of
+ equivalent register. */
+ else if (dest == stack_pointer_rtx
+ && REG_P (src)
+ && REGNO (src) != STACK_POINTER_REGNUM)
+ if (rtx equal = find_reg_note (insn, REG_EQUAL, NULL_RTX))
+ if (GET_CODE (XEXP (equal, 0)) == PLUS
+ && XEXP (XEXP (equal, 0), 0) == stack_pointer_rtx
+ && CONST_INT_P (XEXP (XEXP (equal, 0), 1)))
+ this_adjust = INTVAL (XEXP (XEXP (equal, 0), 1));
+
+ if (this_adjust)
{
- HOST_WIDE_INT this_adjust = INTVAL (XEXP (src, 1));
-
/* If we've not seen an adjustment previously, record
it now and continue. */
if (! last_sp_set)
{
last_sp_set = insn;
last_sp_adjust = this_adjust;
+ if (REG_P (src))
+ {
+ if (copy == NULL)
+ copy = BITMAP_ALLOC (&reg_obstack);
+ last_sp_live = copy;
+ bitmap_copy (last_sp_live, live);
+ }
+ else
+ last_sp_live = NULL;
+ df_simulate_one_insn_forwards (bb, insn, live);
continue;
}
@@ -560,13 +635,16 @@ combine_stack_adjustments_for_block (basic_block bb)
&& try_apply_stack_adjustment (last_sp_set, reflist,
last_sp_adjust
+ this_adjust,
- this_adjust))
+ this_adjust,
+ last_sp_live,
+ insn))
{
/* It worked! */
maybe_move_args_size_note (last_sp_set, insn, false);
maybe_merge_cfa_adjust (last_sp_set, insn, false);
delete_insn (insn);
last_sp_adjust += this_adjust;
+ last_sp_live = NULL;
continue;
}
}
@@ -577,10 +655,12 @@ combine_stack_adjustments_for_block (basic_block bb)
? last_sp_adjust >= 0 : last_sp_adjust <= 0)
{
if (no_unhandled_cfa (last_sp_set)
+ && !REG_P (src)
&& try_apply_stack_adjustment (insn, reflist,
last_sp_adjust
+ this_adjust,
- -last_sp_adjust))
+ -last_sp_adjust,
+ NULL, NULL))
{
/* It worked! */
maybe_move_args_size_note (insn, last_sp_set, true);
@@ -588,8 +668,10 @@ combine_stack_adjustments_for_block (basic_block bb)
delete_insn (last_sp_set);
last_sp_set = insn;
last_sp_adjust += this_adjust;
+ last_sp_live = NULL;
free_csa_reflist (reflist);
reflist = NULL;
+ df_simulate_one_insn_forwards (bb, insn, live);
continue;
}
}
@@ -612,6 +694,16 @@ combine_stack_adjustments_for_block (basic_block bb)
reflist = NULL;
last_sp_set = insn;
last_sp_adjust = this_adjust;
+ if (REG_P (src))
+ {
+ if (copy == NULL)
+ copy = BITMAP_ALLOC (&reg_obstack);
+ last_sp_live = copy;
+ bitmap_copy (last_sp_live, live);
+ }
+ else
+ last_sp_live = NULL;
+ df_simulate_one_insn_forwards (bb, insn, live);
continue;
}
@@ -641,7 +733,8 @@ combine_stack_adjustments_for_block (basic_block bb)
&& !reg_mentioned_p (stack_pointer_rtx, src)
&& memory_address_p (GET_MODE (dest), stack_pointer_rtx)
&& try_apply_stack_adjustment (insn, reflist, 0,
- -last_sp_adjust))
+ -last_sp_adjust,
+ NULL, NULL))
{
if (last2_sp_set)
maybe_move_args_size_note (last2_sp_set, last_sp_set, false);
@@ -652,13 +745,17 @@ combine_stack_adjustments_for_block (basic_block bb)
reflist = NULL;
last_sp_set = NULL;
last_sp_adjust = 0;
+ last_sp_live = NULL;
+ df_simulate_one_insn_forwards (bb, insn, live);
continue;
}
}
- if (!CALL_P (insn) && last_sp_set
- && record_stack_refs (insn, &reflist))
- continue;
+ if (!CALL_P (insn) && last_sp_set && record_stack_refs (insn, &reflist))
+ {
+ df_simulate_one_insn_forwards (bb, insn, live);
+ continue;
+ }
/* Otherwise, we were not able to process the instruction.
Do not continue collecting data across such a one. */
@@ -676,7 +773,10 @@ combine_stack_adjustments_for_block (basic_block bb)
last2_sp_set = NULL;
last_sp_set = NULL;
last_sp_adjust = 0;
+ last_sp_live = NULL;
}
+
+ df_simulate_one_insn_forwards (bb, insn, live);
}
if (last_sp_set && last_sp_adjust == 0)
@@ -687,6 +787,8 @@ combine_stack_adjustments_for_block (basic_block bb)
if (reflist)
free_csa_reflist (reflist);
+ if (copy)
+ BITMAP_FREE (copy);
}
static unsigned int
diff --git a/gcc/postreload.c b/gcc/postreload.c
index 8849679..677b824 100644
--- a/gcc/postreload.c
+++ b/gcc/postreload.c
@@ -97,6 +97,16 @@ reload_cse_simplify (rtx_insn *insn, rtx testreg)
if (NO_FUNCTION_CSE && CALL_P (insn))
return false;
+ /* Remember if this insn has been sp += const_int. */
+ rtx sp_set = set_for_reg_notes (insn);
+ rtx sp_addend = NULL_RTX;
+ if (sp_set
+ && SET_DEST (sp_set) == stack_pointer_rtx
+ && GET_CODE (SET_SRC (sp_set)) == PLUS
+ && XEXP (SET_SRC (sp_set), 0) == stack_pointer_rtx
+ && CONST_INT_P (XEXP (SET_SRC (sp_set), 1)))
+ sp_addend = XEXP (SET_SRC (sp_set), 1);
+
if (GET_CODE (body) == SET)
{
int count = 0;
@@ -180,6 +190,15 @@ reload_cse_simplify (rtx_insn *insn, rtx testreg)
reload_cse_simplify_operands (insn, testreg);
}
+ /* If sp += const_int insn is changed into sp = reg;, add REG_EQUAL
+ note so that the stack_adjustments pass can undo it if beneficial. */
+ if (sp_addend
+ && SET_DEST (sp_set) == stack_pointer_rtx
+ && REG_P (SET_SRC (sp_set)))
+ set_dst_reg_note (insn, REG_EQUAL,
+ gen_rtx_PLUS (Pmode, stack_pointer_rtx,
+ sp_addend), stack_pointer_rtx);
+
done:
return (EDGE_COUNT (insn_bb->succs) != insn_bb_succs);
}
generated by cgit v1.1 at 2025-05-22 12:16:28 +0000