/* Combine stack adjustments.
- Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
- 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
- Free Software Foundation, Inc.
+ Copyright (C) 1987-2019 Free Software Foundation, Inc.
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
+#include "backend.h"
#include "rtl.h"
-#include "tm_p.h"
+#include "df.h"
#include "insn-config.h"
+#include "memmodel.h"
+#include "emit-rtl.h"
#include "recog.h"
-#include "output.h"
-#include "regs.h"
-#include "hard-reg-set.h"
-#include "flags.h"
-#include "function.h"
-#include "expr.h"
-#include "basic-block.h"
-#include "df.h"
-#include "except.h"
-#include "toplev.h"
-#include "reload.h"
-#include "timevar.h"
+#include "cfgrtl.h"
#include "tree-pass.h"
+#include "rtl-iter.h"
\f
-/* Turn STACK_GROWS_DOWNWARD into a boolean. */
-#ifdef STACK_GROWS_DOWNWARD
-#undef STACK_GROWS_DOWNWARD
-#define STACK_GROWS_DOWNWARD 1
-#else
-#define STACK_GROWS_DOWNWARD 0
-#endif
-
-/* This structure records stack memory references between stack adjusting
- instructions. */
+/* This structure records two kinds of stack references between stack
+ adjusting instructions: stack references in memory addresses for
+ regular insns and all stack references for debug insns. */
-struct csa_memlist
+struct csa_reflist
{
HOST_WIDE_INT sp_offset;
- rtx insn, *mem;
- struct csa_memlist *next;
+ rtx_insn *insn;
+ rtx *ref;
+ struct csa_reflist *next;
};
static int stack_memref_p (rtx);
-static rtx single_set_for_csa (rtx);
-static void free_csa_memlist (struct csa_memlist *);
-static struct csa_memlist *record_one_stack_memref (rtx, rtx *,
- struct csa_memlist *);
-static int try_apply_stack_adjustment (rtx, struct csa_memlist *,
+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 int record_stack_memrefs (rtx *, void *);
/* Main entry point for stack adjustment combination. */
{
basic_block bb;
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
combine_stack_adjustments_for_block (bb);
}
return 1;
if (GET_CODE (x) == PLUS
&& XEXP (x, 0) == stack_pointer_rtx
- && GET_CODE (XEXP (x, 1)) == CONST_INT)
+ && CONST_INT_P (XEXP (x, 1)))
return 1;
return 0;
tying fp and sp adjustments. */
static rtx
-single_set_for_csa (rtx insn)
+single_set_for_csa (rtx_insn *insn)
{
int i;
rtx tmp = single_set (insn);
&& SET_SRC (this_rtx) == SET_DEST (this_rtx))
;
else if (GET_CODE (this_rtx) != CLOBBER
+ && GET_CODE (this_rtx) != CLOBBER_HIGH
&& GET_CODE (this_rtx) != USE)
return NULL_RTX;
}
return XVECEXP (tmp, 0, 0);
}
-/* Free the list of csa_memlist nodes. */
+/* Free the list of csa_reflist nodes. */
static void
-free_csa_memlist (struct csa_memlist *memlist)
+free_csa_reflist (struct csa_reflist *reflist)
{
- struct csa_memlist *next;
- for (; memlist ; memlist = next)
+ struct csa_reflist *next;
+ for (; reflist ; reflist = next)
{
- next = memlist->next;
- free (memlist);
+ next = reflist->next;
+ free (reflist);
}
}
-/* Create a new csa_memlist node from the given memory reference.
- It is already known that the memory is stack_memref_p. */
+/* Create a new csa_reflist node from the given stack reference.
+ It is already known that the reference is either a MEM satisfying the
+ predicate stack_memref_p or a REG representing the stack pointer. */
-static struct csa_memlist *
-record_one_stack_memref (rtx insn, rtx *mem, struct csa_memlist *next_memlist)
+static struct csa_reflist *
+record_one_stack_ref (rtx_insn *insn, rtx *ref, struct csa_reflist *next_reflist)
{
- struct csa_memlist *ml;
+ struct csa_reflist *ml;
- ml = XNEW (struct csa_memlist);
+ ml = XNEW (struct csa_reflist);
- if (XEXP (*mem, 0) == stack_pointer_rtx)
+ if (REG_P (*ref) || XEXP (*ref, 0) == stack_pointer_rtx)
ml->sp_offset = 0;
else
- ml->sp_offset = INTVAL (XEXP (XEXP (*mem, 0), 1));
+ ml->sp_offset = INTVAL (XEXP (XEXP (*ref, 0), 1));
ml->insn = insn;
- ml->mem = mem;
- ml->next = next_memlist;
+ ml->ref = ref;
+ ml->next = next_reflist;
return ml;
}
+/* We only know how to adjust the CFA; no other frame-related changes
+ may appear in any insn to be deleted. */
+
+static bool
+no_unhandled_cfa (rtx_insn *insn)
+{
+ if (!RTX_FRAME_RELATED_P (insn))
+ return true;
+
+ /* No CFA notes at all is a legacy interpretation like
+ FRAME_RELATED_EXPR, and is context sensitive within
+ the prologue state machine. We can't handle that here. */
+ bool has_cfa_adjust = false;
+
+ for (rtx link = REG_NOTES (insn); link; link = XEXP (link, 1))
+ switch (REG_NOTE_KIND (link))
+ {
+ default:
+ break;
+ case REG_CFA_ADJUST_CFA:
+ has_cfa_adjust = true;
+ break;
+
+ case REG_FRAME_RELATED_EXPR:
+ case REG_CFA_DEF_CFA:
+ case REG_CFA_OFFSET:
+ case REG_CFA_REGISTER:
+ case REG_CFA_EXPRESSION:
+ case REG_CFA_RESTORE:
+ case REG_CFA_SET_VDRAP:
+ case REG_CFA_WINDOW_SAVE:
+ case REG_CFA_FLUSH_QUEUE:
+ case REG_CFA_TOGGLE_RA_MANGLE:
+ return false;
+ }
+
+ return has_cfa_adjust;
+}
+
/* Attempt to apply ADJUST to the stack adjusting insn INSN, as well
- as each of the memories in MEMLIST. Return true on success. */
+ as each of the memories and stack references in REFLIST. Return true
+ on success. */
static int
-try_apply_stack_adjustment (rtx insn, struct csa_memlist *memlist, HOST_WIDE_INT new_adjust,
- HOST_WIDE_INT delta)
+try_apply_stack_adjustment (rtx_insn *insn, struct csa_reflist *reflist,
+ HOST_WIDE_INT new_adjust, HOST_WIDE_INT delta)
{
- struct csa_memlist *ml;
+ struct csa_reflist *ml;
rtx set;
set = single_set_for_csa (insn);
- validate_change (insn, &XEXP (SET_SRC (set), 1), GEN_INT (new_adjust), 1);
+ if (MEM_P (SET_DEST (set)))
+ validate_change (insn, &SET_DEST (set),
+ replace_equiv_address (SET_DEST (set), stack_pointer_rtx),
+ 1);
+ else
+ validate_change (insn, &XEXP (SET_SRC (set), 1), GEN_INT (new_adjust), 1);
- for (ml = memlist; ml ; ml = ml->next)
- validate_change
- (ml->insn, ml->mem,
- replace_equiv_address_nv (*ml->mem,
- plus_constant (stack_pointer_rtx,
- ml->sp_offset - delta)), 1);
+ for (ml = reflist; ml ; ml = ml->next)
+ {
+ rtx new_addr = plus_constant (Pmode, stack_pointer_rtx,
+ ml->sp_offset - delta);
+ rtx new_val;
+
+ if (MEM_P (*ml->ref))
+ new_val = replace_equiv_address_nv (*ml->ref, new_addr);
+ else if (GET_MODE (*ml->ref) == GET_MODE (stack_pointer_rtx))
+ new_val = new_addr;
+ else
+ new_val = lowpart_subreg (GET_MODE (*ml->ref), new_addr,
+ GET_MODE (new_addr));
+ validate_change (ml->insn, ml->ref, new_val, 1);
+ }
if (apply_change_group ())
{
- /* Succeeded. Update our knowledge of the memory references. */
- for (ml = memlist; ml ; ml = ml->next)
+ /* Succeeded. Update our knowledge of the stack references. */
+ for (ml = reflist; ml ; ml = ml->next)
ml->sp_offset -= delta;
return 1;
return 0;
}
-/* Called via for_each_rtx and used to record all stack memory references in
- the insn and discard all other stack pointer references. */
-struct record_stack_memrefs_data
-{
- rtx insn;
- struct csa_memlist *memlist;
-};
+/* For non-debug insns, record all stack memory references in INSN
+ and return true if there were no other (unrecorded) references to the
+ stack pointer. For debug insns, record all stack references regardless
+ of context and unconditionally return true. */
-static int
-record_stack_memrefs (rtx *xp, void *data)
+static bool
+record_stack_refs (rtx_insn *insn, struct csa_reflist **reflist)
{
- rtx x = *xp;
- struct record_stack_memrefs_data *d =
- (struct record_stack_memrefs_data *) data;
- if (!x)
- return 0;
- switch (GET_CODE (x))
+ subrtx_ptr_iterator::array_type array;
+ FOR_EACH_SUBRTX_PTR (iter, array, &PATTERN (insn), NONCONST)
{
- case MEM:
- if (!reg_mentioned_p (stack_pointer_rtx, x))
- return -1;
- /* We are not able to handle correctly all possible memrefs containing
- stack pointer, so this check is necessary. */
- if (stack_memref_p (x))
+ rtx *loc = *iter;
+ rtx x = *loc;
+ switch (GET_CODE (x))
{
- d->memlist = record_one_stack_memref (d->insn, xp, d->memlist);
- return -1;
+ case MEM:
+ if (!reg_mentioned_p (stack_pointer_rtx, x))
+ iter.skip_subrtxes ();
+ /* We are not able to handle correctly all possible memrefs
+ containing stack pointer, so this check is necessary. */
+ else if (stack_memref_p (x))
+ {
+ *reflist = record_one_stack_ref (insn, loc, *reflist);
+ iter.skip_subrtxes ();
+ }
+ /* Try harder for DEBUG_INSNs, handle e.g.
+ (mem (mem (sp + 16) + 4). */
+ else if (!DEBUG_INSN_P (insn))
+ return false;
+ break;
+
+ case REG:
+ /* ??? We want be able to handle non-memory stack pointer
+ references later. For now just discard all insns referring to
+ stack pointer outside mem expressions. We would probably
+ want to teach validate_replace to simplify expressions first.
+
+ We can't just compare with STACK_POINTER_RTX because the
+ reference to the stack pointer might be in some other mode.
+ In particular, an explicit clobber in an asm statement will
+ result in a QImode clobber.
+
+ In DEBUG_INSNs, we want to replace all occurrences, otherwise
+ they will cause -fcompare-debug failures. */
+ if (REGNO (x) == STACK_POINTER_REGNUM)
+ {
+ if (!DEBUG_INSN_P (insn))
+ return false;
+ *reflist = record_one_stack_ref (insn, loc, *reflist);
+ }
+ break;
+
+ default:
+ break;
}
- return 1;
- case REG:
- /* ??? We want be able to handle non-memory stack pointer
- references later. For now just discard all insns referring to
- stack pointer outside mem expressions. We would probably
- want to teach validate_replace to simplify expressions first.
-
- We can't just compare with STACK_POINTER_RTX because the
- reference to the stack pointer might be in some other mode.
- In particular, an explicit clobber in an asm statement will
- result in a QImode clobber. */
- if (REGNO (x) == STACK_POINTER_REGNUM)
- return 1;
- break;
- default:
- break;
}
- return 0;
+ return true;
}
-/* Adjust or create REG_FRAME_RELATED_EXPR note when merging a stack
- adjustment into a frame related insn. */
+/* If INSN has a REG_ARGS_SIZE note, move it to LAST.
+ AFTER is true iff LAST follows INSN in the instruction stream. */
static void
-adjust_frame_related_expr (rtx last_sp_set, rtx insn,
- HOST_WIDE_INT this_adjust)
+maybe_move_args_size_note (rtx_insn *last, rtx_insn *insn, bool after)
{
- rtx note = find_reg_note (last_sp_set, REG_FRAME_RELATED_EXPR, NULL_RTX);
- rtx new_expr = NULL_RTX;
+ rtx note, last_note;
- if (note == NULL_RTX && RTX_FRAME_RELATED_P (insn))
+ note = find_reg_note (insn, REG_ARGS_SIZE, NULL_RTX);
+ if (note == NULL)
return;
- if (note
- && GET_CODE (XEXP (note, 0)) == SEQUENCE
- && XVECLEN (XEXP (note, 0), 0) >= 2)
+ last_note = find_reg_note (last, REG_ARGS_SIZE, NULL_RTX);
+ if (last_note)
{
- rtx expr = XEXP (note, 0);
- rtx last = XVECEXP (expr, 0, XVECLEN (expr, 0) - 1);
- int i;
-
- if (GET_CODE (last) == SET
- && RTX_FRAME_RELATED_P (last) == RTX_FRAME_RELATED_P (insn)
- && SET_DEST (last) == stack_pointer_rtx
- && GET_CODE (SET_SRC (last)) == PLUS
- && XEXP (SET_SRC (last), 0) == stack_pointer_rtx
- && GET_CODE (XEXP (SET_SRC (last), 1)) == CONST_INT)
- {
- XEXP (SET_SRC (last), 1)
- = GEN_INT (INTVAL (XEXP (SET_SRC (last), 1)) + this_adjust);
- return;
- }
+ /* The ARGS_SIZE notes are *not* cumulative. They represent an
+ absolute value, and the "most recent" note wins. */
+ if (!after)
+ XEXP (last_note, 0) = XEXP (note, 0);
+ }
+ else
+ add_reg_note (last, REG_ARGS_SIZE, XEXP (note, 0));
+}
- new_expr = gen_rtx_SEQUENCE (VOIDmode,
- rtvec_alloc (XVECLEN (expr, 0) + 1));
- for (i = 0; i < XVECLEN (expr, 0); i++)
- XVECEXP (new_expr, 0, i) = XVECEXP (expr, 0, i);
+/* Merge any REG_CFA_ADJUST_CFA note from SRC into DST.
+ AFTER is true iff DST follows SRC in the instruction stream. */
+
+static void
+maybe_merge_cfa_adjust (rtx_insn *dst, rtx_insn *src, bool after)
+{
+ rtx snote = NULL, dnote = NULL;
+ rtx sexp, dexp;
+ rtx exp1, exp2;
+
+ if (RTX_FRAME_RELATED_P (src))
+ snote = find_reg_note (src, REG_CFA_ADJUST_CFA, NULL_RTX);
+ if (snote == NULL)
+ return;
+ sexp = XEXP (snote, 0);
+
+ if (RTX_FRAME_RELATED_P (dst))
+ dnote = find_reg_note (dst, REG_CFA_ADJUST_CFA, NULL_RTX);
+ if (dnote == NULL)
+ {
+ add_reg_note (dst, REG_CFA_ADJUST_CFA, sexp);
+ return;
}
+ dexp = XEXP (dnote, 0);
+
+ gcc_assert (GET_CODE (sexp) == SET);
+ gcc_assert (GET_CODE (dexp) == SET);
+
+ if (after)
+ exp1 = dexp, exp2 = sexp;
else
+ exp1 = sexp, exp2 = dexp;
+
+ SET_SRC (exp1) = simplify_replace_rtx (SET_SRC (exp1), SET_DEST (exp2),
+ SET_SRC (exp2));
+ XEXP (dnote, 0) = exp1;
+}
+
+/* Return the next (or previous) active insn within BB. */
+
+static rtx_insn *
+prev_active_insn_bb (basic_block bb, rtx_insn *insn)
+{
+ for (insn = PREV_INSN (insn);
+ insn != PREV_INSN (BB_HEAD (bb));
+ insn = PREV_INSN (insn))
+ if (active_insn_p (insn))
+ return insn;
+ return NULL;
+}
+
+static rtx_insn *
+next_active_insn_bb (basic_block bb, rtx_insn *insn)
+{
+ for (insn = NEXT_INSN (insn);
+ insn != NEXT_INSN (BB_END (bb));
+ insn = NEXT_INSN (insn))
+ if (active_insn_p (insn))
+ return insn;
+ return NULL;
+}
+
+/* If INSN has a REG_ARGS_SIZE note, if possible move it to PREV. Otherwise
+ search for a nearby candidate within BB where we can stick the note. */
+
+static void
+force_move_args_size_note (basic_block bb, rtx_insn *prev, rtx_insn *insn)
+{
+ rtx note;
+ rtx_insn *test, *next_candidate, *prev_candidate;
+
+ /* If PREV exists, tail-call to the logic in the other function. */
+ if (prev)
{
- new_expr = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (2));
- if (note)
- XVECEXP (new_expr, 0, 0) = XEXP (note, 0);
- else
- {
- rtx expr = copy_rtx (single_set_for_csa (last_sp_set));
+ maybe_move_args_size_note (prev, insn, false);
+ return;
+ }
+
+ /* First, make sure there's anything that needs doing. */
+ note = find_reg_note (insn, REG_ARGS_SIZE, NULL_RTX);
+ if (note == NULL)
+ return;
+
+ /* We need to find a spot between the previous and next exception points
+ where we can place the note and "properly" deallocate the arguments. */
+ next_candidate = prev_candidate = NULL;
- XEXP (SET_SRC (expr), 1)
- = GEN_INT (INTVAL (XEXP (SET_SRC (expr), 1)) - this_adjust);
- RTX_FRAME_RELATED_P (expr) = 1;
- XVECEXP (new_expr, 0, 0) = expr;
+ /* It is often the case that we have insns in the order:
+ call
+ add sp (previous deallocation)
+ sub sp (align for next arglist)
+ push arg
+ and the add/sub cancel. Therefore we begin by searching forward. */
+
+ test = insn;
+ while ((test = next_active_insn_bb (bb, test)) != NULL)
+ {
+ /* Found an existing note: nothing to do. */
+ if (find_reg_note (test, REG_ARGS_SIZE, NULL_RTX))
+ return;
+ /* Found something that affects unwinding. Stop searching. */
+ if (CALL_P (test) || !insn_nothrow_p (test))
+ break;
+ if (next_candidate == NULL)
+ next_candidate = test;
+ }
+
+ test = insn;
+ while ((test = prev_active_insn_bb (bb, test)) != NULL)
+ {
+ rtx tnote;
+ /* Found a place that seems logical to adjust the stack. */
+ tnote = find_reg_note (test, REG_ARGS_SIZE, NULL_RTX);
+ if (tnote)
+ {
+ XEXP (tnote, 0) = XEXP (note, 0);
+ return;
}
+ if (prev_candidate == NULL)
+ prev_candidate = test;
+ /* Found something that affects unwinding. Stop searching. */
+ if (CALL_P (test) || !insn_nothrow_p (test))
+ break;
}
- XVECEXP (new_expr, 0, XVECLEN (new_expr, 0) - 1)
- = copy_rtx (single_set_for_csa (insn));
- RTX_FRAME_RELATED_P (XVECEXP (new_expr, 0, XVECLEN (new_expr, 0) - 1))
- = RTX_FRAME_RELATED_P (insn);
- if (note)
- XEXP (note, 0) = new_expr;
+ if (prev_candidate)
+ test = prev_candidate;
+ else if (next_candidate)
+ test = next_candidate;
else
- REG_NOTES (last_sp_set)
- = gen_rtx_EXPR_LIST (REG_FRAME_RELATED_EXPR, new_expr,
- REG_NOTES (last_sp_set));
+ {
+ /* ??? We *must* have a place, lest we ICE on the lost adjustment.
+ Options are: dummy clobber insn, nop, or prevent the removal of
+ the sp += 0 insn. */
+ /* TODO: Find another way to indicate to the dwarf2 code that we
+ have not in fact lost an adjustment. */
+ test = emit_insn_before (gen_rtx_CLOBBER (VOIDmode, const0_rtx), insn);
+ }
+ add_reg_note (test, REG_ARGS_SIZE, XEXP (note, 0));
}
/* Subroutine of combine_stack_adjustments, called for each basic block. */
combine_stack_adjustments_for_block (basic_block bb)
{
HOST_WIDE_INT last_sp_adjust = 0;
- rtx last_sp_set = NULL_RTX;
- struct csa_memlist *memlist = NULL;
- rtx insn, next, set;
- struct record_stack_memrefs_data data;
+ rtx_insn *last_sp_set = NULL;
+ rtx_insn *last2_sp_set = NULL;
+ struct csa_reflist *reflist = NULL;
+ rtx_insn *insn, *next;
+ rtx set;
bool end_of_block = false;
for (insn = BB_HEAD (bb); !end_of_block ; insn = next)
continue;
set = single_set_for_csa (insn);
+ if (set && find_reg_note (insn, REG_STACK_CHECK, NULL_RTX))
+ set = NULL_RTX;
if (set)
{
rtx dest = SET_DEST (set);
if (dest == stack_pointer_rtx
&& GET_CODE (src) == PLUS
&& XEXP (src, 0) == stack_pointer_rtx
- && GET_CODE (XEXP (src, 1)) == CONST_INT)
+ && CONST_INT_P (XEXP (src, 1)))
{
HOST_WIDE_INT this_adjust = INTVAL (XEXP (src, 1));
continue;
}
- /* If not all recorded memrefs can be adjusted, or the
+ /* If not all recorded refs can be adjusted, or the
adjustment is now too large for a constant addition,
we cannot merge the two stack adjustments.
Also we need to be careful to not move stack pointer
such that we create stack accesses outside the allocated
area. We can combine an allocation into the first insn,
- or a deallocation into the second insn. We can not
+ or a deallocation into the second insn. We cannot
combine an allocation followed by a deallocation.
The only somewhat frequent occurrence of the later is when
/* Combine an allocation into the first instruction. */
if (STACK_GROWS_DOWNWARD ? this_adjust <= 0 : this_adjust >= 0)
{
- if (try_apply_stack_adjustment (last_sp_set, memlist,
- last_sp_adjust + this_adjust,
- this_adjust))
+ if (no_unhandled_cfa (insn)
+ && try_apply_stack_adjustment (last_sp_set, reflist,
+ last_sp_adjust
+ + this_adjust,
+ this_adjust))
{
- if (RTX_FRAME_RELATED_P (last_sp_set))
- adjust_frame_related_expr (last_sp_set, insn,
- this_adjust);
/* 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;
continue;
else if (STACK_GROWS_DOWNWARD
? last_sp_adjust >= 0 : last_sp_adjust <= 0)
{
- if (try_apply_stack_adjustment (insn, memlist,
- last_sp_adjust + this_adjust,
- -last_sp_adjust))
+ if (no_unhandled_cfa (last_sp_set)
+ && try_apply_stack_adjustment (insn, reflist,
+ last_sp_adjust
+ + this_adjust,
+ -last_sp_adjust))
{
/* It worked! */
+ maybe_move_args_size_note (insn, last_sp_set, true);
+ maybe_merge_cfa_adjust (insn, last_sp_set, true);
delete_insn (last_sp_set);
last_sp_set = insn;
last_sp_adjust += this_adjust;
- free_csa_memlist (memlist);
- memlist = NULL;
+ free_csa_reflist (reflist);
+ reflist = NULL;
continue;
}
}
/* Combination failed. Restart processing from here. If
deallocation+allocation conspired to cancel, we can
delete the old deallocation insn. */
- if (last_sp_set && last_sp_adjust == 0)
- delete_insn (last_sp_set);
- free_csa_memlist (memlist);
- memlist = NULL;
+ if (last_sp_set)
+ {
+ if (last_sp_adjust == 0 && no_unhandled_cfa (last_sp_set))
+ {
+ maybe_move_args_size_note (insn, last_sp_set, true);
+ maybe_merge_cfa_adjust (insn, last_sp_set, true);
+ delete_insn (last_sp_set);
+ }
+ else
+ last2_sp_set = last_sp_set;
+ }
+ free_csa_reflist (reflist);
+ reflist = NULL;
last_sp_set = insn;
last_sp_adjust = this_adjust;
continue;
}
- /* Find a predecrement of exactly the previous adjustment and
- turn it into a direct store. Obviously we can't do this if
- there were any intervening uses of the stack pointer. */
- if (memlist == NULL
- && MEM_P (dest)
- && ((GET_CODE (XEXP (dest, 0)) == PRE_DEC
- && (last_sp_adjust
- == (HOST_WIDE_INT) GET_MODE_SIZE (GET_MODE (dest))))
- || (GET_CODE (XEXP (dest, 0)) == PRE_MODIFY
+ /* Find a store with pre-(dec|inc)rement or pre-modify of exactly
+ the previous adjustment and turn it into a simple store. This
+ is equivalent to anticipating the stack adjustment so this must
+ be an allocation. */
+ if (MEM_P (dest)
+ && ((STACK_GROWS_DOWNWARD
+ ? (GET_CODE (XEXP (dest, 0)) == PRE_DEC
+ && known_eq (last_sp_adjust,
+ GET_MODE_SIZE (GET_MODE (dest))))
+ : (GET_CODE (XEXP (dest, 0)) == PRE_INC
+ && known_eq (-last_sp_adjust,
+ GET_MODE_SIZE (GET_MODE (dest)))))
+ || ((STACK_GROWS_DOWNWARD
+ ? last_sp_adjust >= 0 : last_sp_adjust <= 0)
+ && GET_CODE (XEXP (dest, 0)) == PRE_MODIFY
&& GET_CODE (XEXP (XEXP (dest, 0), 1)) == PLUS
- && XEXP (XEXP (XEXP (dest, 0), 1), 0) == stack_pointer_rtx
- && (GET_CODE (XEXP (XEXP (XEXP (dest, 0), 1), 1))
- == CONST_INT)
- && (INTVAL (XEXP (XEXP (XEXP (dest, 0), 1), 1))
- == -last_sp_adjust)))
+ && XEXP (XEXP (XEXP (dest, 0), 1), 0)
+ == stack_pointer_rtx
+ && GET_CODE (XEXP (XEXP (XEXP (dest, 0), 1), 1))
+ == CONST_INT
+ && INTVAL (XEXP (XEXP (XEXP (dest, 0), 1), 1))
+ == -last_sp_adjust))
&& XEXP (XEXP (dest, 0), 0) == stack_pointer_rtx
- && ! reg_mentioned_p (stack_pointer_rtx, src)
+ && !reg_mentioned_p (stack_pointer_rtx, src)
&& memory_address_p (GET_MODE (dest), stack_pointer_rtx)
- && validate_change (insn, &SET_DEST (set),
- replace_equiv_address (dest,
- stack_pointer_rtx),
- 0))
+ && try_apply_stack_adjustment (insn, reflist, 0,
+ -last_sp_adjust))
{
+ if (last2_sp_set)
+ maybe_move_args_size_note (last2_sp_set, last_sp_set, false);
+ else
+ maybe_move_args_size_note (insn, last_sp_set, true);
delete_insn (last_sp_set);
- free_csa_memlist (memlist);
- memlist = NULL;
- last_sp_set = NULL_RTX;
+ free_csa_reflist (reflist);
+ reflist = NULL;
+ last_sp_set = NULL;
last_sp_adjust = 0;
continue;
}
}
- data.insn = insn;
- data.memlist = memlist;
if (!CALL_P (insn) && last_sp_set
- && !for_each_rtx (&PATTERN (insn), record_stack_memrefs, &data))
- {
- memlist = data.memlist;
- continue;
- }
- memlist = data.memlist;
+ && record_stack_refs (insn, &reflist))
+ continue;
/* Otherwise, we were not able to process the instruction.
Do not continue collecting data across such a one. */
|| reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))))
{
if (last_sp_set && last_sp_adjust == 0)
- delete_insn (last_sp_set);
- free_csa_memlist (memlist);
- memlist = NULL;
- last_sp_set = NULL_RTX;
+ {
+ force_move_args_size_note (bb, last2_sp_set, last_sp_set);
+ delete_insn (last_sp_set);
+ }
+ free_csa_reflist (reflist);
+ reflist = NULL;
+ last2_sp_set = NULL;
+ last_sp_set = NULL;
last_sp_adjust = 0;
}
}
if (last_sp_set && last_sp_adjust == 0)
- delete_insn (last_sp_set);
+ {
+ force_move_args_size_note (bb, last2_sp_set, last_sp_set);
+ delete_insn (last_sp_set);
+ }
- if (memlist)
- free_csa_memlist (memlist);
+ if (reflist)
+ free_csa_reflist (reflist);
}
\f
-
-static bool
-gate_handle_stack_adjustments (void)
+static unsigned int
+rest_of_handle_stack_adjustments (void)
{
- return (optimize > 0);
+ df_note_add_problem ();
+ df_analyze ();
+ combine_stack_adjustments ();
+ return 0;
}
-static unsigned int
-rest_of_handle_stack_adjustments (void)
+namespace {
+
+const pass_data pass_data_stack_adjustments =
+{
+ RTL_PASS, /* type */
+ "csa", /* name */
+ OPTGROUP_NONE, /* optinfo_flags */
+ TV_COMBINE_STACK_ADJUST, /* tv_id */
+ 0, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_df_finish, /* todo_flags_finish */
+};
+
+class pass_stack_adjustments : public rtl_opt_pass
{
- cleanup_cfg (flag_crossjumping ? CLEANUP_CROSSJUMP : 0);
+public:
+ pass_stack_adjustments (gcc::context *ctxt)
+ : rtl_opt_pass (pass_data_stack_adjustments, ctxt)
+ {}
+
+ /* opt_pass methods: */
+ virtual bool gate (function *);
+ virtual unsigned int execute (function *)
+ {
+ return rest_of_handle_stack_adjustments ();
+ }
+}; // class pass_stack_adjustments
+
+bool
+pass_stack_adjustments::gate (function *)
+{
/* This is kind of a heuristic. We need to run combine_stack_adjustments
- even for machines with possibly nonzero RETURN_POPS_ARGS
+ even for machines with possibly nonzero TARGET_RETURN_POPS_ARGS
and ACCUMULATE_OUTGOING_ARGS. We expect that only ports having
push instructions will have popping returns. */
#ifndef PUSH_ROUNDING
- if (!ACCUMULATE_OUTGOING_ARGS)
+ if (ACCUMULATE_OUTGOING_ARGS)
+ return false;
#endif
- {
- df_note_add_problem ();
- df_analyze ();
- combine_stack_adjustments ();
- }
- return 0;
+ return flag_combine_stack_adjustments;
}
-struct rtl_opt_pass pass_stack_adjustments =
-{
- {
- RTL_PASS,
- "csa", /* name */
- gate_handle_stack_adjustments, /* gate */
- rest_of_handle_stack_adjustments, /* execute */
- NULL, /* sub */
- NULL, /* next */
- 0, /* static_pass_number */
- 0, /* tv_id */
- 0, /* properties_required */
- 0, /* properties_provided */
- 0, /* properties_destroyed */
- 0, /* todo_flags_start */
- TODO_df_finish | TODO_verify_rtl_sharing |
- TODO_dump_func |
- TODO_ggc_collect, /* todo_flags_finish */
- }
-};
+} // anon namespace
+rtl_opt_pass *
+make_pass_stack_adjustments (gcc::context *ctxt)
+{
+ return new pass_stack_adjustments (ctxt);
+}
projects / gcc.git / blobdiff