/* RTL-based forward propagation pass for GNU compiler.
- Copyright (C) 2005-2019 Free Software Foundation, Inc.
+ Copyright (C) 2005-2020 Free Software Foundation, Inc.
Contributed by Paolo Bonzini and Steven Bosscher.
This file is part of GCC.
single_def_use_dom_walker::before_dom_children (basic_block bb)
{
int bb_index = bb->index;
- struct df_md_bb_info *md_bb_info = df_md_get_bb_info (bb_index);
- struct df_lr_bb_info *lr_bb_info = df_lr_get_bb_info (bb_index);
+ class df_md_bb_info *md_bb_info = df_md_get_bb_info (bb_index);
+ class df_lr_bb_info *lr_bb_info = df_lr_get_bb_info (bb_index);
rtx_insn *insn;
bitmap_copy (local_md, &md_bb_info->in);
df_maybe_reorganize_use_refs (DF_REF_ORDER_BY_INSN_WITH_NOTES);
use_def_ref.create (DF_USES_TABLE_SIZE ());
- use_def_ref.safe_grow_cleared (DF_USES_TABLE_SIZE ());
+ use_def_ref.safe_grow_cleared (DF_USES_TABLE_SIZE (), true);
reg_defs.create (max_reg_num ());
- reg_defs.safe_grow_cleared (max_reg_num ());
+ reg_defs.safe_grow_cleared (max_reg_num (), true);
reg_defs_stack.create (n_basic_blocks_for_fn (cfun) * 10);
local_md = BITMAP_ALLOC (NULL);
PR_OPTIMIZE_FOR_SPEED = 4
};
+/* Check that X has a single def. */
+
+static bool
+reg_single_def_p (rtx x)
+{
+ if (!REG_P (x))
+ return false;
+
+ int regno = REGNO (x);
+ return (DF_REG_DEF_COUNT (regno) == 1
+ && !bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)), regno));
+}
/* Replace all occurrences of OLD in *PX with NEW and try to simplify the
resulting expression. Replace *PX with a new RTL expression if an
tem = simplify_gen_subreg (mode, op0, GET_MODE (SUBREG_REG (x)),
SUBREG_BYTE (x));
}
+
+ else
+ {
+ rtvec vec;
+ rtvec newvec;
+ const char *fmt = GET_RTX_FORMAT (code);
+ rtx op;
+
+ for (int i = 0; fmt[i]; i++)
+ switch (fmt[i])
+ {
+ case 'E':
+ vec = XVEC (x, i);
+ newvec = vec;
+ for (int j = 0; j < GET_NUM_ELEM (vec); j++)
+ {
+ op = RTVEC_ELT (vec, j);
+ valid_ops &= propagate_rtx_1 (&op, old_rtx, new_rtx, flags);
+ if (op != RTVEC_ELT (vec, j))
+ {
+ if (newvec == vec)
+ {
+ newvec = shallow_copy_rtvec (vec);
+ if (!tem)
+ tem = shallow_copy_rtx (x);
+ XVEC (tem, i) = newvec;
+ }
+ RTVEC_ELT (newvec, j) = op;
+ }
+ }
+ break;
+
+ case 'e':
+ if (XEXP (x, i))
+ {
+ op = XEXP (x, i);
+ valid_ops &= propagate_rtx_1 (&op, old_rtx, new_rtx, flags);
+ if (op != XEXP (x, i))
+ {
+ if (!tem)
+ tem = shallow_copy_rtx (x);
+ XEXP (tem, i) = op;
+ }
+ }
+ break;
+ }
+ }
+
break;
case RTX_OBJ:
|| CONSTANT_P (new_rtx)
|| (GET_CODE (new_rtx) == SUBREG
&& REG_P (SUBREG_REG (new_rtx))
- && !paradoxical_subreg_p (mode, GET_MODE (SUBREG_REG (new_rtx)))))
+ && !paradoxical_subreg_p (new_rtx)))
flags |= PR_CAN_APPEAR;
if (!varying_mem_p (new_rtx))
flags |= PR_HANDLE_MEM;
/* Set up the use-def chain. */
if (DF_REF_ID (use) >= (int) use_def_ref.length ())
- use_def_ref.safe_grow_cleared (DF_REF_ID (use) + 1);
+ use_def_ref.safe_grow_cleared (DF_REF_ID (use) + 1, true);
if (flag_checking)
gcc_assert (sparseset_bit_p (active_defs_check, regno));
/* Given a use USE of an insn, if it has a single reaching
definition, try to forward propagate it into that insn.
- Return true if cfg cleanup will be needed. */
+ Return true if cfg cleanup will be needed.
+ REG_PROP_ONLY is true if we should only propagate register copies. */
static bool
-forward_propagate_into (df_ref use)
+forward_propagate_into (df_ref use, bool reg_prop_only = false)
{
df_ref def;
rtx_insn *def_insn, *use_insn;
if (DF_REF_IS_ARTIFICIAL (def))
return false;
- /* Do not propagate loop invariant definitions inside the loop. */
- if (DF_REF_BB (def)->loop_father != DF_REF_BB (use)->loop_father)
- return false;
-
/* Check if the use is still present in the insn! */
use_insn = DF_REF_INSN (use);
if (DF_REF_FLAGS (use) & DF_REF_IN_NOTE)
if (!def_set)
return false;
+ if (reg_prop_only
+ && (!reg_single_def_p (SET_SRC (def_set))
+ || !reg_single_def_p (SET_DEST (def_set))))
+ return false;
+
+ /* Allow propagations into a loop only for reg-to-reg copies, since
+ replacing one register by another shouldn't increase the cost. */
+
+ if (DF_REF_BB (def)->loop_father != DF_REF_BB (use)->loop_father
+ && (!reg_single_def_p (SET_SRC (def_set))
+ || !reg_single_def_p (SET_DEST (def_set))))
+ return false;
+
/* Only try one kind of propagation. If two are possible, we'll
do it on the following iterations. */
if (forward_propagate_and_simplify (use, def_insn, def_set)
}
static unsigned int
-fwprop (void)
+fwprop (bool fwprop_addr_p)
{
unsigned i;
df_ref use = DF_USES_GET (i);
if (use)
- if (DF_REF_TYPE (use) == DF_REF_REG_USE
- || DF_REF_BB (use)->loop_father == NULL
- /* The outer most loop is not really a loop. */
- || loop_outer (DF_REF_BB (use)->loop_father) == NULL)
- forward_propagate_into (use);
+ {
+ if (DF_REF_TYPE (use) == DF_REF_REG_USE
+ || DF_REF_BB (use)->loop_father == NULL
+ /* The outer most loop is not really a loop. */
+ || loop_outer (DF_REF_BB (use)->loop_father) == NULL)
+ forward_propagate_into (use, fwprop_addr_p);
+
+ else if (fwprop_addr_p)
+ forward_propagate_into (use, false);
+ }
}
fwprop_done ();
/* opt_pass methods: */
virtual bool gate (function *) { return gate_fwprop (); }
- virtual unsigned int execute (function *) { return fwprop (); }
+ virtual unsigned int execute (function *) { return fwprop (false); }
}; // class pass_rtl_fwprop
return new pass_rtl_fwprop (ctxt);
}
-static unsigned int
-fwprop_addr (void)
-{
- unsigned i;
-
- fwprop_init ();
-
- /* Go through all the uses. df_uses_create will create new ones at the
- end, and we'll go through them as well. */
- for (i = 0; i < DF_USES_TABLE_SIZE (); i++)
- {
- if (!propagations_left)
- break;
-
- df_ref use = DF_USES_GET (i);
- if (use)
- if (DF_REF_TYPE (use) != DF_REF_REG_USE
- && DF_REF_BB (use)->loop_father != NULL
- /* The outer most loop is not really a loop. */
- && loop_outer (DF_REF_BB (use)->loop_father) != NULL)
- forward_propagate_into (use);
- }
-
- fwprop_done ();
- return 0;
-}
-
namespace {
const pass_data pass_data_rtl_fwprop_addr =
/* opt_pass methods: */
virtual bool gate (function *) { return gate_fwprop (); }
- virtual unsigned int execute (function *) { return fwprop_addr (); }
+ virtual unsigned int execute (function *) { return fwprop (true); }
}; // class pass_rtl_fwprop_addr
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