static int label_tick;
-/* Reset to label_tick for each label. */
+/* Reset to label_tick for each extended basic block in scanning order. */
static int label_tick_ebb_start;
/* Subroutine of try_combine. Determine whether the combine replacement
patterns NEWPAT, NEWI2PAT and NEWOTHERPAT are cheaper according to
insn_rtx_cost that the original instruction sequence I1, I2, I3 and
- undobuf.other_insn. Note that I1 and/or NEWI2PAT may be NULL_RTX.
+ undobuf.other_insn. Note that I1 and/or NEWI2PAT may be NULL_RTX.
NEWOTHERPAT and undobuf.other_insn may also both be NULL_RTX. This
function returns false, if the costs of all instructions can be
estimated, and the replacements are more expensive than the original
register and establishing log links when def is encountered.
Note that we do not clear next_use array in order to save time,
so we have to test whether the use is in the same basic block as def.
-
+
There are a few cases below when we do not consider the definition or
usage -- these are taken from original flow.c did. Don't ask me why it is
done this way; I don't know and if it works, I don't want to know. */
if (INSN_P (insn))
free_INSN_LIST_list (&LOG_LINKS (insn));
}
-
-
-
\f
/* Main entry point for combiner. F is the first insn of the function.
NREGS is the first unused pseudo-reg number.
#endif
rtx links, nextlinks;
rtx first;
+ basic_block last_bb;
int new_direct_jump_p = 0;
problems when, for example, we have j <<= 1 in a loop. */
nonzero_sign_valid = 0;
+ label_tick = label_tick_ebb_start = 1;
/* Scan all SETs and see if we can deduce anything about what
bits are known to be zero for some registers and how many copies
for what bits are known to be set. */
setup_incoming_promotions (first);
+ /* Allow the entry block and the first block to fall into the same EBB.
+ Conceptually the incoming promotions are assigned to the entry block. */
+ last_bb = ENTRY_BLOCK_PTR;
create_log_links ();
- label_tick_ebb_start = ENTRY_BLOCK_PTR->index;
FOR_EACH_BB (this_basic_block)
{
optimize_this_for_speed_p = optimize_bb_for_speed_p (this_basic_block);
last_call_luid = 0;
mem_last_set = -1;
- label_tick = this_basic_block->index;
+
+ label_tick++;
if (!single_pred_p (this_basic_block)
- || single_pred (this_basic_block)->index != label_tick - 1)
+ || single_pred (this_basic_block) != last_bb)
label_tick_ebb_start = label_tick;
+ last_bb = this_basic_block;
+
FOR_BB_INSNS (this_basic_block, insn)
if (INSN_P (insn) && BLOCK_FOR_INSN (insn))
{
nonzero_sign_valid = 1;
/* Now scan all the insns in forward order. */
-
- label_tick_ebb_start = ENTRY_BLOCK_PTR->index;
+ label_tick = label_tick_ebb_start = 1;
init_reg_last ();
setup_incoming_promotions (first);
+ last_bb = ENTRY_BLOCK_PTR;
FOR_EACH_BB (this_basic_block)
{
optimize_this_for_speed_p = optimize_bb_for_speed_p (this_basic_block);
last_call_luid = 0;
mem_last_set = -1;
- label_tick = this_basic_block->index;
+
+ label_tick++;
if (!single_pred_p (this_basic_block)
- || single_pred (this_basic_block)->index != label_tick - 1)
+ || single_pred (this_basic_block) != last_bb)
label_tick_ebb_start = label_tick;
+ last_bb = this_basic_block;
+
rtl_profile_for_bb (this_basic_block);
for (insn = BB_HEAD (this_basic_block);
insn != NEXT_INSN (BB_END (this_basic_block));
for (arg = DECL_ARGUMENTS (current_function_decl); arg;
arg = TREE_CHAIN (arg))
{
- rtx reg = DECL_INCOMING_RTL (arg);
+ rtx x, reg = DECL_INCOMING_RTL (arg);
int uns1, uns3;
enum machine_mode mode1, mode2, mode3, mode4;
mode2 = TYPE_MODE (DECL_ARG_TYPE (arg));
uns3 = TYPE_UNSIGNED (DECL_ARG_TYPE (arg));
- /* The mode and signedness of the argument as it is actually passed,
+ /* The mode and signedness of the argument as it is actually passed,
after any TARGET_PROMOTE_FUNCTION_ARGS-driven ABI promotions. */
mode3 = promote_function_mode (DECL_ARG_TYPE (arg), mode2, &uns3,
TREE_TYPE (cfun->decl), 0);
/* The mode of the register in which the argument is being passed. */
mode4 = GET_MODE (reg);
- /* Eliminate sign extensions in the callee when possible. Only
- do this when:
- (a) a mode promotion has occurred;
- (b) the mode of the register is the same as the mode of
- the argument as it is passed; and
- (c) the signedness does not change across any of the promotions; and
- (d) when no language-level promotions (which we cannot guarantee
- will have been done by an external caller) are necessary,
- unless we know that this function is only ever called from
- the current compilation unit -- all of whose call sites will
- do the mode1 --> mode2 promotion. */
- if (mode1 != mode3
- && mode3 == mode4
- && uns1 == uns3
- && (mode1 == mode2 || strictly_local))
- {
- /* Record that the value was promoted from mode1 to mode3,
- so that any sign extension at the head of the current
- function may be eliminated. */
- rtx x;
- x = gen_rtx_CLOBBER (mode1, const0_rtx);
- x = gen_rtx_fmt_e ((uns3 ? ZERO_EXTEND : SIGN_EXTEND), mode3, x);
- record_value_for_reg (reg, first, x);
- }
+ /* Eliminate sign extensions in the callee when:
+ (a) A mode promotion has occurred; */
+ if (mode1 == mode3)
+ continue;
+ /* (b) The mode of the register is the same as the mode of
+ the argument as it is passed; */
+ if (mode3 != mode4)
+ continue;
+ /* (c) There's no language level extension; */
+ if (mode1 == mode2)
+ ;
+ /* (c.1) All callers are from the current compilation unit. If that's
+ the case we don't have to rely on an ABI, we only have to know
+ what we're generating right now, and we know that we will do the
+ mode1 to mode2 promotion with the given sign. */
+ else if (!strictly_local)
+ continue;
+ /* (c.2) The combination of the two promotions is useful. This is
+ true when the signs match, or if the first promotion is unsigned.
+ In the later case, (sign_extend (zero_extend x)) is the same as
+ (zero_extend (zero_extend x)), so make sure to force UNS3 true. */
+ else if (uns1)
+ uns3 = true;
+ else if (uns3)
+ continue;
+
+ /* Record that the value was promoted from mode1 to mode3,
+ so that any sign extension at the head of the current
+ function may be eliminated. */
+ x = gen_rtx_CLOBBER (mode1, const0_rtx);
+ x = gen_rtx_fmt_e ((uns3 ? ZERO_EXTEND : SIGN_EXTEND), mode3, x);
+ record_value_for_reg (reg, first, x);
}
}
return x;
}
-#endif
/* Auxiliary data structure for propagate_for_debug_stmt. */
struct rtx_subst_pair
{
- rtx from, to;
- bool changed;
-#ifdef AUTO_INC_DEC
+ rtx to;
bool adjusted;
bool after;
-#endif
};
-/* Clean up any auto-updates in PAIR->to the first time it is called
- for a PAIR. PAIR->adjusted is used to tell whether we've cleaned
- up before. */
+/* DATA points to an rtx_subst_pair. Return the value that should be
+ substituted. */
-static void
-auto_adjust_pair (struct rtx_subst_pair *pair ATTRIBUTE_UNUSED)
+static rtx
+propagate_for_debug_subst (rtx from ATTRIBUTE_UNUSED, void *data)
{
-#ifdef AUTO_INC_DEC
+ struct rtx_subst_pair *pair = (struct rtx_subst_pair *)data;
+
if (!pair->adjusted)
{
pair->adjusted = true;
pair->to = cleanup_auto_inc_dec (pair->to, pair->after, VOIDmode);
+ return pair->to;
}
-#endif
-}
-
-/* If *LOC is the same as FROM in the struct rtx_subst_pair passed as
- DATA, replace it with a copy of TO. Handle SUBREGs of *LOC as
- well. */
-
-static int
-propagate_for_debug_subst (rtx *loc, void *data)
-{
- struct rtx_subst_pair *pair = (struct rtx_subst_pair *)data;
- rtx from = pair->from, to = pair->to;
- rtx x = *loc, s = x;
-
- if (rtx_equal_p (x, from)
- || (GET_CODE (x) == SUBREG && rtx_equal_p ((s = SUBREG_REG (x)), from)))
- {
- auto_adjust_pair (pair);
- if (pair->to != to)
- to = pair->to;
- else
- to = copy_rtx (to);
- if (s != x)
- {
- gcc_assert (GET_CODE (x) == SUBREG && SUBREG_REG (x) == s);
- to = simplify_gen_subreg (GET_MODE (x), to,
- GET_MODE (from), SUBREG_BYTE (x));
- }
- *loc = wrap_constant (GET_MODE (x), to);
- pair->changed = true;
- return -1;
- }
-
- return 0;
+ return copy_rtx (pair->to);
}
+#endif
/* Replace occurrences of DEST with SRC in DEBUG_INSNs between INSN
and LAST. If MOVE holds, debug insns must also be moved past
static void
propagate_for_debug (rtx insn, rtx last, rtx dest, rtx src, bool move)
{
- struct rtx_subst_pair p;
- rtx next, move_pos = move ? last : NULL_RTX;
-
- p.from = dest;
- p.to = src;
- p.changed = false;
+ rtx next, move_pos = move ? last : NULL_RTX, loc;
#ifdef AUTO_INC_DEC
+ struct rtx_subst_pair p;
+ p.to = src;
p.adjusted = false;
p.after = move;
#endif
next = NEXT_INSN (insn);
if (DEBUG_INSN_P (insn))
{
- for_each_rtx (&INSN_VAR_LOCATION_LOC (insn),
- propagate_for_debug_subst, &p);
- if (!p.changed)
+#ifdef AUTO_INC_DEC
+ loc = simplify_replace_fn_rtx (INSN_VAR_LOCATION_LOC (insn),
+ dest, propagate_for_debug_subst, &p);
+#else
+ loc = simplify_replace_rtx (INSN_VAR_LOCATION_LOC (insn), dest, src);
+#endif
+ if (loc == INSN_VAR_LOCATION_LOC (insn))
continue;
- p.changed = false;
+ INSN_VAR_LOCATION_LOC (insn) = loc;
if (move_pos)
{
remove_insn (insn);
if (newi2pat && new_i2_notes)
distribute_notes (new_i2_notes, i2, i2, NULL_RTX, NULL_RTX, NULL_RTX);
-
+
if (new_i3_notes)
distribute_notes (new_i3_notes, i3, i3, NULL_RTX, NULL_RTX, NULL_RTX);
}
df_insn_rescan (i3);
}
-
+
/* Set new_direct_jump_p if a new return or simple jump instruction
has been created. Adjust the CFG accordingly. */
*new_direct_jump_p = 1;
update_cfg_for_uncondjump (i3);
}
-
+
combine_successes++;
undo_commit ();
if (GET_CODE (XEXP (x, 0)) == CONST
|| GET_CODE (XEXP (x, 0)) == SYMBOL_REF)
{
+ enum machine_mode address_mode
+ = targetm.addr_space.address_mode (MEM_ADDR_SPACE (x));
+
SUBST (XEXP (x, 0),
- gen_rtx_LO_SUM (Pmode,
- gen_rtx_HIGH (Pmode, XEXP (x, 0)),
+ gen_rtx_LO_SUM (address_mode,
+ gen_rtx_HIGH (address_mode, XEXP (x, 0)),
XEXP (x, 0)));
return &XEXP (XEXP (x, 0), 0);
}
it will not remain in the result. */
if (GET_CODE (XEXP (x, 0)) == PLUS
&& CONST_INT_P (XEXP (XEXP (x, 0), 1))
- && ! memory_address_p (GET_MODE (x), XEXP (x, 0)))
+ && ! memory_address_addr_space_p (GET_MODE (x), XEXP (x, 0),
+ MEM_ADDR_SPACE (x)))
{
rtx reg = regno_reg_rtx[FIRST_PSEUDO_REGISTER];
rtx seq = combine_split_insns (gen_rtx_SET (VOIDmode, reg,
&& NONJUMP_INSN_P (NEXT_INSN (seq))
&& GET_CODE (PATTERN (NEXT_INSN (seq))) == SET
&& SET_DEST (PATTERN (NEXT_INSN (seq))) == reg
- && memory_address_p (GET_MODE (x),
- SET_SRC (PATTERN (NEXT_INSN (seq)))))
+ && memory_address_addr_space_p
+ (GET_MODE (x), SET_SRC (PATTERN (NEXT_INSN (seq))),
+ MEM_ADDR_SPACE (x)))
{
rtx src1 = SET_SRC (PATTERN (seq));
rtx src2 = SET_SRC (PATTERN (NEXT_INSN (seq)));
/* If we have a PLUS whose first operand is complex, try computing it
separately by making a split there. */
if (GET_CODE (XEXP (x, 0)) == PLUS
- && ! memory_address_p (GET_MODE (x), XEXP (x, 0))
+ && ! memory_address_addr_space_p (GET_MODE (x), XEXP (x, 0),
+ MEM_ADDR_SPACE (x))
&& ! OBJECT_P (XEXP (XEXP (x, 0), 0))
&& ! (GET_CODE (XEXP (XEXP (x, 0), 0)) == SUBREG
&& OBJECT_P (SUBREG_REG (XEXP (XEXP (x, 0), 0)))))
force_to_mode (XEXP (x, 0), GET_MODE (XEXP (x, 0)),
GET_MODE_MASK (mode), 0));
+ /* We can truncate a constant value and return it. */
+ if (CONST_INT_P (XEXP (x, 0)))
+ return gen_int_mode (INTVAL (XEXP (x, 0)), mode);
+
/* Similarly to what we do in simplify-rtx.c, a truncate of a register
whose value is a comparison can be replaced with a subreg if
STORE_FLAG_VALUE permits. */
}
/* Try simplify a*(b/c) as (a*b)/c. */
- if (FLOAT_MODE_P (mode) && flag_associative_math
+ if (FLOAT_MODE_P (mode) && flag_associative_math
&& GET_CODE (XEXP (x, 0)) == DIV)
{
rtx tem = simplify_binary_operation (MULT, mode,
tem = make_compound_operation (SUBREG_REG (x), in_code);
{
- rtx simplified;
- simplified = simplify_subreg (GET_MODE (x), tem, GET_MODE (tem),
- SUBREG_BYTE (x));
+ rtx simplified = simplify_subreg (mode, tem, GET_MODE (SUBREG_REG (x)),
+ SUBREG_BYTE (x));
if (simplified)
tem = simplified;
if (GET_CODE (tem) != GET_CODE (SUBREG_REG (x))
- && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (tem))
+ && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
&& subreg_lowpart_p (x))
{
rtx newer = force_to_mode (tem, mode, ~(HOST_WIDE_INT) 0,
enum rtx_code outer_code, inner_code;
rtx decomposed, distributed, inner_op0, inner_op1, new_op0, new_op1, tmp;
+ /* Distributivity is not true for floating point as it can change the
+ value. So we don't do it unless -funsafe-math-optimizations. */
+ if (FLOAT_MODE_P (GET_MODE (x))
+ && ! flag_unsafe_math_optimizations)
+ return NULL_RTX;
+
decomposed = XEXP (x, n);
if (!ARITHMETIC_P (decomposed))
return NULL_RTX;
if (REG_P (XEXP (XVECEXP (newpat, 0, i), 0))
&& ! reg_dead_at_p (XEXP (XVECEXP (newpat, 0, i), 0), insn))
return -1;
- if (GET_CODE (XEXP (XVECEXP (newpat, 0, i), 0)) != SCRATCH)
+ if (GET_CODE (XEXP (XVECEXP (newpat, 0, i), 0)) != SCRATCH)
{
gcc_assert (REG_P (XEXP (XVECEXP (newpat, 0, i), 0)));
notes = alloc_reg_note (REG_UNUSED,
{
int zero_extended;
+ /* If this is a test for negative, we can make an explicit
+ test of the sign bit. Test this first so we can use
+ a paradoxical subreg to extend OP0. */
+
+ if (op1 == const0_rtx && (code == LT || code == GE)
+ && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
+ {
+ op0 = simplify_gen_binary (AND, tmode,
+ gen_lowpart (tmode, op0),
+ GEN_INT ((HOST_WIDE_INT) 1
+ << (GET_MODE_BITSIZE (mode)
+ - 1)));
+ code = (code == LT) ? NE : EQ;
+ break;
+ }
+
/* If the only nonzero bits in OP0 and OP1 are those in the
narrower mode and this is an equality or unsigned comparison,
we can use the wider mode. Similarly for sign-extended
XEXP (op0, 0)),
gen_lowpart (tmode,
XEXP (op0, 1)));
-
- op0 = gen_lowpart (tmode, op0);
- if (zero_extended && CONST_INT_P (op1))
- op1 = GEN_INT (INTVAL (op1) & GET_MODE_MASK (mode));
- op1 = gen_lowpart (tmode, op1);
- break;
- }
-
- /* If this is a test for negative, we can make an explicit
- test of the sign bit. */
-
- if (op1 == const0_rtx && (code == LT || code == GE)
- && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
- {
- op0 = simplify_gen_binary (AND, tmode,
- gen_lowpart (tmode, op0),
- GEN_INT ((HOST_WIDE_INT) 1
- << (GET_MODE_BITSIZE (mode)
- - 1)));
- code = (code == LT) ? NE : EQ;
- break;
+ else
+ {
+ if (zero_extended)
+ {
+ op0 = simplify_gen_unary (ZERO_EXTEND, tmode, op0, mode);
+ op1 = simplify_gen_unary (ZERO_EXTEND, tmode, op1, mode);
+ }
+ else
+ {
+ op0 = simplify_gen_unary (SIGN_EXTEND, tmode, op0, mode);
+ op1 = simplify_gen_unary (SIGN_EXTEND, tmode, op1, mode);
+ }
+ break;
+ }
}
}
case, we must replace it with (clobber (const_int 0)) to prevent
infinite loops. */
rsp = VEC_index (reg_stat_type, reg_stat, regno);
- if (value && ! get_last_value_validate (&value, insn,
- rsp->last_set_label, 0))
+ if (value && !get_last_value_validate (&value, insn, label_tick, 0))
{
value = copy_rtx (value);
- if (! get_last_value_validate (&value, insn,
- rsp->last_set_label, 1))
+ if (!get_last_value_validate (&value, insn, label_tick, 1))
value = 0;
}
}
}
\f
-/* Utility routine for the following function. Verify that all the registers
- mentioned in *LOC are valid when *LOC was part of a value set when
- label_tick == TICK. Return 0 if some are not.
-
- If REPLACE is nonzero, replace the invalid reference with
- (clobber (const_int 0)) and return 1. This replacement is useful because
- we often can get useful information about the form of a value (e.g., if
- it was produced by a shift that always produces -1 or 0) even though
- we don't know exactly what registers it was produced from. */
+/* Verify that all the registers and memory references mentioned in *LOC are
+ still valid. *LOC was part of a value set in INSN when label_tick was
+ equal to TICK. Return 0 if some are not. If REPLACE is nonzero, replace
+ the invalid references with (clobber (const_int 0)) and return 1. This
+ replacement is useful because we often can get useful information about
+ the form of a value (e.g., if it was produced by a shift that always
+ produces -1 or 0) even though we don't know exactly what registers it
+ was produced from. */
static int
get_last_value_validate (rtx *loc, rtx insn, int tick, int replace)
return 1;
}
- /* If this is a memory reference, make sure that there were
- no stores after it that might have clobbered the value. We don't
- have alias info, so we assume any store invalidates it. */
+ /* If this is a memory reference, make sure that there were no stores after
+ it that might have clobbered the value. We don't have alias info, so we
+ assume any store invalidates it. Moreover, we only have local UIDs, so
+ we also assume that there were stores in the intervening basic blocks. */
else if (MEM_P (x) && !MEM_READONLY_P (x)
- && DF_INSN_LUID (insn) <= mem_last_set)
+ && (tick != label_tick || DF_INSN_LUID (insn) <= mem_last_set))
{
if (replace)
*loc = gen_rtx_CLOBBER (GET_MODE (x), const0_rtx);
return 0;
/* If the value has all its registers valid, return it. */
- if (get_last_value_validate (&value, rsp->last_set,
- rsp->last_set_label, 0))
+ if (get_last_value_validate (&value, rsp->last_set, rsp->last_set_label, 0))
return value;
/* Otherwise, make a copy and replace any invalid register with
(clobber (const_int 0)). If that fails for some reason, return 0. */
value = copy_rtx (value);
- if (get_last_value_validate (&value, rsp->last_set,
- rsp->last_set_label, 1))
+ if (get_last_value_validate (&value, rsp->last_set, rsp->last_set_label, 1))
return value;
return 0;
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