/* Common subexpression elimination for GNU compiler.
Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
- 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
This file is part of GCC.
<http://www.gnu.org/licenses/>. */
#include "config.h"
-/* stdio.h must precede rtl.h for FFS. */
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "regs.h"
#include "basic-block.h"
#include "flags.h"
-#include "real.h"
#include "insn-config.h"
#include "recog.h"
#include "function.h"
#define REGNO_QTY_VALID_P(N) (REG_QTY (N) >= 0)
+/* Compare table_elt X and Y and return true iff X is cheaper than Y. */
+
+#define CHEAPER(X, Y) \
+ (preferable ((X)->cost, (X)->regcost, (Y)->cost, (Y)->regcost) < 0)
+
static struct table_elt *table[HASH_SIZE];
/* Chain of `struct table_elt's made so far for this function
static int constant_pool_entries_cost;
static int constant_pool_entries_regcost;
+/* Trace a patch through the CFG. */
+
+struct branch_path
+{
+ /* The basic block for this path entry. */
+ basic_block bb;
+};
+
/* This data describes a block that will be processed by
cse_extended_basic_block. */
/* Size of current branch path, if any. */
int path_size;
/* Current path, indicating which basic_blocks will be processed. */
- struct branch_path
- {
- /* The basic block for this path entry. */
- basic_block bb;
- } *path;
+ struct branch_path *path;
};
static struct table_elt *lookup (rtx, unsigned, enum machine_mode);
static struct table_elt *lookup_for_remove (rtx, unsigned, enum machine_mode);
static rtx lookup_as_function (rtx, enum rtx_code);
+static struct table_elt *insert_with_costs (rtx, struct table_elt *, unsigned,
+ enum machine_mode, int, int);
static struct table_elt *insert (rtx, struct table_elt *, unsigned,
enum machine_mode);
static void merge_equiv_classes (struct table_elt *, struct table_elt *);
static int cse_change_cc_mode (rtx *, void *);
static void cse_change_cc_mode_insn (rtx, rtx);
static void cse_change_cc_mode_insns (rtx, rtx, rtx);
-static enum machine_mode cse_cc_succs (basic_block, rtx, rtx, bool);
+static enum machine_mode cse_cc_succs (basic_block, basic_block, rtx, rtx,
+ bool);
\f
#undef RTL_HOOKS_GEN_LOWPART
return false;
case PLUS:
- if (GET_CODE (XEXP (x, 1)) != CONST_INT)
+ if (!CONST_INT_P (XEXP (x, 1)))
return false;
return fixed_base_plus_p (XEXP (x, 0));
{
if (regno < FIRST_PSEUDO_REGISTER)
{
- if (SMALL_REGISTER_CLASSES)
+ if (targetm.small_register_classes_for_mode_p (GET_MODE (x)))
return 1;
*cost_p += 2;
}
return mention_regs (x);
}
\f
+
+/* Compute upper and lower anchors for CST. Also compute the offset of CST
+ from these anchors/bases such that *_BASE + *_OFFS = CST. Return false iff
+ CST is equal to an anchor. */
+
+static bool
+compute_const_anchors (rtx cst,
+ HOST_WIDE_INT *lower_base, HOST_WIDE_INT *lower_offs,
+ HOST_WIDE_INT *upper_base, HOST_WIDE_INT *upper_offs)
+{
+ HOST_WIDE_INT n = INTVAL (cst);
+
+ *lower_base = n & ~(targetm.const_anchor - 1);
+ if (*lower_base == n)
+ return false;
+
+ *upper_base =
+ (n + (targetm.const_anchor - 1)) & ~(targetm.const_anchor - 1);
+ *upper_offs = n - *upper_base;
+ *lower_offs = n - *lower_base;
+ return true;
+}
+
+/* Insert the equivalence between ANCHOR and (REG + OFF) in mode MODE. */
+
+static void
+insert_const_anchor (HOST_WIDE_INT anchor, rtx reg, HOST_WIDE_INT offs,
+ enum machine_mode mode)
+{
+ struct table_elt *elt;
+ unsigned hash;
+ rtx anchor_exp;
+ rtx exp;
+
+ anchor_exp = GEN_INT (anchor);
+ hash = HASH (anchor_exp, mode);
+ elt = lookup (anchor_exp, hash, mode);
+ if (!elt)
+ elt = insert (anchor_exp, NULL, hash, mode);
+
+ exp = plus_constant (reg, offs);
+ /* REG has just been inserted and the hash codes recomputed. */
+ mention_regs (exp);
+ hash = HASH (exp, mode);
+
+ /* Use the cost of the register rather than the whole expression. When
+ looking up constant anchors we will further offset the corresponding
+ expression therefore it does not make sense to prefer REGs over
+ reg-immediate additions. Prefer instead the oldest expression. Also
+ don't prefer pseudos over hard regs so that we derive constants in
+ argument registers from other argument registers rather than from the
+ original pseudo that was used to synthesize the constant. */
+ insert_with_costs (exp, elt, hash, mode, COST (reg), 1);
+}
+
+/* The constant CST is equivalent to the register REG. Create
+ equivalences between the two anchors of CST and the corresponding
+ register-offset expressions using REG. */
+
+static void
+insert_const_anchors (rtx reg, rtx cst, enum machine_mode mode)
+{
+ HOST_WIDE_INT lower_base, lower_offs, upper_base, upper_offs;
+
+ if (!compute_const_anchors (cst, &lower_base, &lower_offs,
+ &upper_base, &upper_offs))
+ return;
+
+ /* Ignore anchors of value 0. Constants accessible from zero are
+ simple. */
+ if (lower_base != 0)
+ insert_const_anchor (lower_base, reg, -lower_offs, mode);
+
+ if (upper_base != 0)
+ insert_const_anchor (upper_base, reg, -upper_offs, mode);
+}
+
+/* We need to express ANCHOR_ELT->exp + OFFS. Walk the equivalence list of
+ ANCHOR_ELT and see if offsetting any of the entries by OFFS would create a
+ valid expression. Return the cheapest and oldest of such expressions. In
+ *OLD, return how old the resulting expression is compared to the other
+ equivalent expressions. */
+
+static rtx
+find_reg_offset_for_const (struct table_elt *anchor_elt, HOST_WIDE_INT offs,
+ unsigned *old)
+{
+ struct table_elt *elt;
+ unsigned idx;
+ struct table_elt *match_elt;
+ rtx match;
+
+ /* Find the cheapest and *oldest* expression to maximize the chance of
+ reusing the same pseudo. */
+
+ match_elt = NULL;
+ match = NULL_RTX;
+ for (elt = anchor_elt->first_same_value, idx = 0;
+ elt;
+ elt = elt->next_same_value, idx++)
+ {
+ if (match_elt && CHEAPER (match_elt, elt))
+ return match;
+
+ if (REG_P (elt->exp)
+ || (GET_CODE (elt->exp) == PLUS
+ && REG_P (XEXP (elt->exp, 0))
+ && GET_CODE (XEXP (elt->exp, 1)) == CONST_INT))
+ {
+ rtx x;
+
+ /* Ignore expressions that are no longer valid. */
+ if (!REG_P (elt->exp) && !exp_equiv_p (elt->exp, elt->exp, 1, false))
+ continue;
+
+ x = plus_constant (elt->exp, offs);
+ if (REG_P (x)
+ || (GET_CODE (x) == PLUS
+ && IN_RANGE (INTVAL (XEXP (x, 1)),
+ -targetm.const_anchor,
+ targetm.const_anchor - 1)))
+ {
+ match = x;
+ match_elt = elt;
+ *old = idx;
+ }
+ }
+ }
+
+ return match;
+}
+
+/* Try to express the constant SRC_CONST using a register+offset expression
+ derived from a constant anchor. Return it if successful or NULL_RTX,
+ otherwise. */
+
+static rtx
+try_const_anchors (rtx src_const, enum machine_mode mode)
+{
+ struct table_elt *lower_elt, *upper_elt;
+ HOST_WIDE_INT lower_base, lower_offs, upper_base, upper_offs;
+ rtx lower_anchor_rtx, upper_anchor_rtx;
+ rtx lower_exp = NULL_RTX, upper_exp = NULL_RTX;
+ unsigned lower_old, upper_old;
+
+ if (!compute_const_anchors (src_const, &lower_base, &lower_offs,
+ &upper_base, &upper_offs))
+ return NULL_RTX;
+
+ lower_anchor_rtx = GEN_INT (lower_base);
+ upper_anchor_rtx = GEN_INT (upper_base);
+ lower_elt = lookup (lower_anchor_rtx, HASH (lower_anchor_rtx, mode), mode);
+ upper_elt = lookup (upper_anchor_rtx, HASH (upper_anchor_rtx, mode), mode);
+
+ if (lower_elt)
+ lower_exp = find_reg_offset_for_const (lower_elt, lower_offs, &lower_old);
+ if (upper_elt)
+ upper_exp = find_reg_offset_for_const (upper_elt, upper_offs, &upper_old);
+
+ if (!lower_exp)
+ return upper_exp;
+ if (!upper_exp)
+ return lower_exp;
+
+ /* Return the older expression. */
+ return (upper_old > lower_old ? upper_exp : lower_exp);
+}
+\f
/* Look in or update the hash table. */
/* Remove table element ELT from use in the table.
struct table_elt *p
= lookup (x, SAFE_HASH (x, VOIDmode), GET_MODE (x));
- /* If we are looking for a CONST_INT, the mode doesn't really matter, as
- long as we are narrowing. So if we looked in vain for a mode narrower
- than word_mode before, look for word_mode now. */
- if (p == 0 && code == CONST_INT
- && GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (word_mode))
- {
- x = copy_rtx (x);
- PUT_MODE (x, word_mode);
- p = lookup (x, SAFE_HASH (x, VOIDmode), word_mode);
- }
-
if (p == 0)
return 0;
return 0;
}
-/* Insert X in the hash table, assuming HASH is its hash code
- and CLASSP is an element of the class it should go in
- (or 0 if a new class should be made).
- It is inserted at the proper position to keep the class in
- the order cheapest first.
+/* Insert X in the hash table, assuming HASH is its hash code and
+ CLASSP is an element of the class it should go in (or 0 if a new
+ class should be made). COST is the code of X and reg_cost is the
+ cost of registers in X. It is inserted at the proper position to
+ keep the class in the order cheapest first.
MODE is the machine-mode of X, or if X is an integer constant
with VOIDmode then MODE is the mode with which X will be used.
If necessary, update table showing constant values of quantities. */
-#define CHEAPER(X, Y) \
- (preferable ((X)->cost, (X)->regcost, (Y)->cost, (Y)->regcost) < 0)
-
static struct table_elt *
-insert (rtx x, struct table_elt *classp, unsigned int hash, enum machine_mode mode)
+insert_with_costs (rtx x, struct table_elt *classp, unsigned int hash,
+ enum machine_mode mode, int cost, int reg_cost)
{
struct table_elt *elt;
elt->exp = x;
elt->canon_exp = NULL_RTX;
- elt->cost = COST (x);
- elt->regcost = approx_reg_cost (x);
+ elt->cost = cost;
+ elt->regcost = reg_cost;
elt->next_same_value = 0;
elt->prev_same_value = 0;
elt->next_same_hash = table[hash];
return elt;
}
+
+/* Wrap insert_with_costs by passing the default costs. */
+
+static struct table_elt *
+insert (rtx x, struct table_elt *classp, unsigned int hash,
+ enum machine_mode mode)
+{
+ return
+ insert_with_costs (x, classp, hash, mode, COST (x), approx_reg_cost (x));
+}
+
\f
/* Given two equivalence classes, CLASS1 and CLASS2, put all the entries from
CLASS2 into CLASS1. This is done when we have reached an insn which makes
{
struct check_dependence_data *d = (struct check_dependence_data *) data;
if (*x && MEM_P (*x))
- return canon_true_dependence (d->exp, d->mode, d->addr, *x,
+ return canon_true_dependence (d->exp, d->mode, d->addr, *x, NULL_RTX,
cse_rtx_varies_p);
else
return 0;
return hash;
}
-/* Same as hash_rtx, but call CB on each rtx if it is not NULL.
+/* Same as hash_rtx, but call CB on each rtx if it is not NULL.
When the callback returns true, we continue with the new rtx. */
unsigned
return hash;
/* Invoke the callback first. */
- if (cb != NULL
+ if (cb != NULL
&& ((*cb) (x, mode, &newx, &newmode)))
{
hash += hash_rtx_cb (newx, newmode, do_not_record_p,
record = true;
else if (GET_MODE_CLASS (GET_MODE (x)) == MODE_CC)
record = true;
- else if (SMALL_REGISTER_CLASSES)
+ else if (targetm.small_register_classes_for_mode_p (GET_MODE (x)))
record = false;
else if (CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (regno)))
record = false;
{
elt = CONST_VECTOR_ELT (x, i);
hash += hash_rtx_cb (elt, GET_MODE (elt),
- do_not_record_p, hash_arg_in_memory_p,
+ do_not_record_p, hash_arg_in_memory_p,
have_reg_qty, cb);
}
x = XEXP (x, i);
goto repeat;
}
-
- hash += hash_rtx_cb (XEXP (x, i), 0, do_not_record_p,
+
+ hash += hash_rtx_cb (XEXP (x, i), VOIDmode, do_not_record_p,
hash_arg_in_memory_p,
have_reg_qty, cb);
break;
case 'E':
for (j = 0; j < XVECLEN (x, i); j++)
- hash += hash_rtx_cb (XVECEXP (x, i, j), 0, do_not_record_p,
+ hash += hash_rtx_cb (XVECEXP (x, i, j), VOIDmode, do_not_record_p,
hash_arg_in_memory_p,
have_reg_qty, cb);
break;
if (GET_MODE (x) != GET_MODE (y))
return 0;
+ /* MEMs refering to different address space are not equivalent. */
+ if (code == MEM && MEM_ADDR_SPACE (x) != MEM_ADDR_SPACE (y))
+ return 0;
+
switch (code)
{
case PC:
They could e.g. be two different entities allocated into the
same space on the stack (see e.g. PR25130). In that case, the
MEM addresses can be the same, even though the two MEMs are
- absolutely not equivalent.
-
+ absolutely not equivalent.
+
But because really all MEM attributes should be the same for
equivalent MEMs, we just use the invariant that MEMs that have
the same attributes share the same mem_attrs data structure. */
}
if (GET_CODE (x) == PLUS
- && GET_CODE (XEXP (x, 1)) == CONST_INT
+ && CONST_INT_P (XEXP (x, 1))
&& REG_P (XEXP (x, 0))
&& REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))))
{
{
case RTX_UNARY:
{
- int is_const = 0;
-
/* We can't simplify extension ops unless we know the
original mode. */
if ((code == ZERO_EXTEND || code == SIGN_EXTEND)
&& mode_arg0 == VOIDmode)
break;
- /* If we had a CONST, strip it off and put it back later if we
- fold. */
- if (const_arg0 != 0 && GET_CODE (const_arg0) == CONST)
- is_const = 1, const_arg0 = XEXP (const_arg0, 0);
-
new_rtx = simplify_unary_operation (code, mode,
const_arg0 ? const_arg0 : folded_arg0,
mode_arg0);
- /* NEG of PLUS could be converted into MINUS, but that causes
- expressions of the form
- (CONST (MINUS (CONST_INT) (SYMBOL_REF)))
- which many ports mistakenly treat as LEGITIMATE_CONSTANT_P.
- FIXME: those ports should be fixed. */
- if (new_rtx != 0 && is_const
- && GET_CODE (new_rtx) == PLUS
- && (GET_CODE (XEXP (new_rtx, 0)) == SYMBOL_REF
- || GET_CODE (XEXP (new_rtx, 0)) == LABEL_REF)
- && GET_CODE (XEXP (new_rtx, 1)) == CONST_INT)
- new_rtx = gen_rtx_CONST (mode, new_rtx);
}
break;
constant through simplifications. */
p = lookup (folded_arg0, SAFE_HASH (folded_arg0, mode_arg0),
mode_arg0);
-
+
if (p != NULL)
{
cheapest_simplification = x;
if (y != 0
&& (inner_const = equiv_constant (XEXP (y, 1))) != 0
- && GET_CODE (inner_const) == CONST_INT
+ && CONST_INT_P (inner_const)
&& INTVAL (inner_const) != 0)
folded_arg0 = gen_rtx_IOR (mode_arg0, XEXP (y, 0), inner_const);
}
the smallest negative number this would overflow: depending
on the mode, this would either just be the same value (and
hence not save anything) or be incorrect. */
- if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT
+ if (const_arg1 != 0 && CONST_INT_P (const_arg1)
&& INTVAL (const_arg1) < 0
/* This used to test
case MINUS:
/* If we have (MINUS Y C), see if Y is known to be (PLUS Z C2).
If so, produce (PLUS Z C2-C). */
- if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT)
+ if (const_arg1 != 0 && CONST_INT_P (const_arg1))
{
rtx y = lookup_as_function (XEXP (x, 0), PLUS);
- if (y && GET_CODE (XEXP (y, 1)) == CONST_INT)
+ if (y && CONST_INT_P (XEXP (y, 1)))
return fold_rtx (plus_constant (copy_rtx (y),
-INTVAL (const_arg1)),
NULL_RTX);
if the intermediate operation's result has only one reference. */
if (REG_P (folded_arg0)
- && const_arg1 && GET_CODE (const_arg1) == CONST_INT)
+ && const_arg1 && CONST_INT_P (const_arg1))
{
int is_shift
= (code == ASHIFT || code == ASHIFTRT || code == LSHIFTRT);
rtx y, inner_const, new_const;
+ rtx canon_const_arg1 = const_arg1;
enum rtx_code associate_code;
if (is_shift
|| INTVAL (const_arg1) < 0))
{
if (SHIFT_COUNT_TRUNCATED)
- const_arg1 = GEN_INT (INTVAL (const_arg1)
- & (GET_MODE_BITSIZE (mode) - 1));
+ canon_const_arg1 = GEN_INT (INTVAL (const_arg1)
+ & (GET_MODE_BITSIZE (mode)
+ - 1));
else
break;
}
break;
inner_const = equiv_constant (fold_rtx (XEXP (y, 1), 0));
- if (!inner_const || GET_CODE (inner_const) != CONST_INT)
+ if (!inner_const || !CONST_INT_P (inner_const))
break;
/* Don't associate these operations if they are a PLUS with the
associate_code = (is_shift || code == MINUS ? PLUS : code);
new_const = simplify_binary_operation (associate_code, mode,
- const_arg1, inner_const);
+ canon_const_arg1,
+ inner_const);
if (new_const == 0)
break;
of shifts. */
if (is_shift
- && GET_CODE (new_const) == CONST_INT
+ && CONST_INT_P (new_const)
&& INTVAL (new_const) >= GET_MODE_BITSIZE (mode))
{
/* As an exception, we can turn an ASHIFTRT of this
if (GET_CODE (x) == SUBREG)
{
+ enum machine_mode mode = GET_MODE (x);
+ enum machine_mode imode = GET_MODE (SUBREG_REG (x));
rtx new_rtx;
/* See if we previously assigned a constant value to this SUBREG. */
|| (new_rtx = lookup_as_function (x, CONST_FIXED)) != 0)
return new_rtx;
+ /* If we didn't and if doing so makes sense, see if we previously
+ assigned a constant value to the enclosing word mode SUBREG. */
+ if (GET_MODE_SIZE (mode) < GET_MODE_SIZE (word_mode)
+ && GET_MODE_SIZE (word_mode) < GET_MODE_SIZE (imode))
+ {
+ int byte = SUBREG_BYTE (x) - subreg_lowpart_offset (mode, word_mode);
+ if (byte >= 0 && (byte % UNITS_PER_WORD) == 0)
+ {
+ rtx y = gen_rtx_SUBREG (word_mode, SUBREG_REG (x), byte);
+ new_rtx = lookup_as_function (y, CONST_INT);
+ if (new_rtx)
+ return gen_lowpart (mode, new_rtx);
+ }
+ }
+
+ /* Otherwise see if we already have a constant for the inner REG. */
if (REG_P (SUBREG_REG (x))
&& (new_rtx = equiv_constant (SUBREG_REG (x))) != 0)
- return simplify_subreg (GET_MODE (x), SUBREG_REG (x),
- GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
+ return simplify_subreg (mode, new_rtx, imode, SUBREG_BYTE (x));
return 0;
}
apply_change_group ();
fold_rtx (x, insn);
}
+ else if (DEBUG_INSN_P (insn))
+ canon_reg (PATTERN (insn), insn);
/* Store the equivalent value in SRC_EQV, if different, or if the DEST
is a STRICT_LOW_PART. The latter condition is necessary because SRC_EQV
for (i = 0; i < n_sets; i++)
{
+ bool repeat = false;
rtx src, dest;
rtx src_folded;
struct table_elt *elt = 0, *p;
rtx src_eqv_here;
rtx src_const = 0;
rtx src_related = 0;
+ bool src_related_is_const_anchor = false;
struct table_elt *src_const_elt = 0;
int src_cost = MAX_COST;
int src_eqv_cost = MAX_COST;
{
rtx width = XEXP (SET_DEST (sets[i].rtl), 1);
- if (GET_CODE (src) == CONST_INT
- && GET_CODE (width) == CONST_INT
+ if (CONST_INT_P (src)
+ && CONST_INT_P (width)
&& INTVAL (width) < HOST_BITS_PER_WIDE_INT
&& (INTVAL (src) & ((HOST_WIDE_INT) (-1) << INTVAL (width))))
src_folded
/* See if we have a CONST_INT that is already in a register in a
wider mode. */
- if (src_const && src_related == 0 && GET_CODE (src_const) == CONST_INT
+ if (src_const && src_related == 0 && CONST_INT_P (src_const)
&& GET_MODE_CLASS (mode) == MODE_INT
&& GET_MODE_BITSIZE (mode) < BITS_PER_WORD)
{
enum machine_mode wider_mode;
for (wider_mode = GET_MODE_WIDER_MODE (mode);
- GET_MODE_BITSIZE (wider_mode) <= BITS_PER_WORD
+ wider_mode != VOIDmode
+ && GET_MODE_BITSIZE (wider_mode) <= BITS_PER_WORD
&& src_related == 0;
wider_mode = GET_MODE_WIDER_MODE (wider_mode))
{
value. */
if (flag_expensive_optimizations && ! src_related
- && GET_CODE (src) == AND && GET_CODE (XEXP (src, 1)) == CONST_INT
+ && GET_CODE (src) == AND && CONST_INT_P (XEXP (src, 1))
&& GET_MODE_SIZE (mode) < UNITS_PER_WORD)
{
enum machine_mode tmode;
}
#endif /* LOAD_EXTEND_OP */
+ /* Try to express the constant using a register+offset expression
+ derived from a constant anchor. */
+
+ if (targetm.const_anchor
+ && !src_related
+ && src_const
+ && GET_CODE (src_const) == CONST_INT)
+ {
+ src_related = try_const_anchors (src_const, mode);
+ src_related_is_const_anchor = src_related != NULL_RTX;
+ }
+
+
if (src == src_folded)
src_folded = 0;
{
src_related_cost = COST (src_related);
src_related_regcost = approx_reg_cost (src_related);
+
+ /* If a const-anchor is used to synthesize a constant that
+ normally requires multiple instructions then slightly prefer
+ it over the original sequence. These instructions are likely
+ to become redundant now. We can't compare against the cost
+ of src_eqv_here because, on MIPS for example, multi-insn
+ constants have zero cost; they are assumed to be hoisted from
+ loops. */
+ if (src_related_is_const_anchor
+ && src_related_cost == src_cost
+ && src_eqv_here)
+ src_related_cost--;
}
}
break;
}
+ /* Try to optimize
+ (set (reg:M N) (const_int A))
+ (set (reg:M2 O) (const_int B))
+ (set (zero_extract:M2 (reg:M N) (const_int C) (const_int D))
+ (reg:M2 O)). */
+ if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT
+ && CONST_INT_P (trial)
+ && CONST_INT_P (XEXP (SET_DEST (sets[i].rtl), 1))
+ && CONST_INT_P (XEXP (SET_DEST (sets[i].rtl), 2))
+ && REG_P (XEXP (SET_DEST (sets[i].rtl), 0))
+ && (GET_MODE_BITSIZE (GET_MODE (SET_DEST (sets[i].rtl)))
+ >= INTVAL (XEXP (SET_DEST (sets[i].rtl), 1)))
+ && ((unsigned) INTVAL (XEXP (SET_DEST (sets[i].rtl), 1))
+ + (unsigned) INTVAL (XEXP (SET_DEST (sets[i].rtl), 2))
+ <= HOST_BITS_PER_WIDE_INT))
+ {
+ rtx dest_reg = XEXP (SET_DEST (sets[i].rtl), 0);
+ rtx width = XEXP (SET_DEST (sets[i].rtl), 1);
+ rtx pos = XEXP (SET_DEST (sets[i].rtl), 2);
+ unsigned int dest_hash = HASH (dest_reg, GET_MODE (dest_reg));
+ struct table_elt *dest_elt
+ = lookup (dest_reg, dest_hash, GET_MODE (dest_reg));
+ rtx dest_cst = NULL;
+
+ if (dest_elt)
+ for (p = dest_elt->first_same_value; p; p = p->next_same_value)
+ if (p->is_const && CONST_INT_P (p->exp))
+ {
+ dest_cst = p->exp;
+ break;
+ }
+ if (dest_cst)
+ {
+ HOST_WIDE_INT val = INTVAL (dest_cst);
+ HOST_WIDE_INT mask;
+ unsigned int shift;
+ if (BITS_BIG_ENDIAN)
+ shift = GET_MODE_BITSIZE (GET_MODE (dest_reg))
+ - INTVAL (pos) - INTVAL (width);
+ else
+ shift = INTVAL (pos);
+ if (INTVAL (width) == HOST_BITS_PER_WIDE_INT)
+ mask = ~(HOST_WIDE_INT) 0;
+ else
+ mask = ((HOST_WIDE_INT) 1 << INTVAL (width)) - 1;
+ val &= ~(mask << shift);
+ val |= (INTVAL (trial) & mask) << shift;
+ val = trunc_int_for_mode (val, GET_MODE (dest_reg));
+ validate_unshare_change (insn, &SET_DEST (sets[i].rtl),
+ dest_reg, 1);
+ validate_unshare_change (insn, &SET_SRC (sets[i].rtl),
+ GEN_INT (val), 1);
+ if (apply_change_group ())
+ {
+ rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
+ if (note)
+ {
+ remove_note (insn, note);
+ df_notes_rescan (insn);
+ }
+ src_eqv = NULL_RTX;
+ src_eqv_elt = NULL;
+ src_eqv_volatile = 0;
+ src_eqv_in_memory = 0;
+ src_eqv_hash = 0;
+ repeat = true;
+ break;
+ }
+ }
+ }
+
/* We don't normally have an insn matching (set (pc) (pc)), so
check for this separately here. We will delete such an
insn below.
}
}
+ /* If we changed the insn too much, handle this set from scratch. */
+ if (repeat)
+ {
+ i--;
+ continue;
+ }
+
src = SET_SRC (sets[i].rtl);
/* In general, it is good to have a SET with SET_SRC == SET_DEST.
{
rtx width = XEXP (SET_DEST (sets[i].rtl), 1);
- if (src_const != 0 && GET_CODE (src_const) == CONST_INT
- && GET_CODE (width) == CONST_INT
+ if (src_const != 0 && CONST_INT_P (src_const)
+ && CONST_INT_P (width)
&& INTVAL (width) < HOST_BITS_PER_WIDE_INT
&& ! (INTVAL (src_const)
& ((HOST_WIDE_INT) (-1) << INTVAL (width))))
elt = insert (dest, sets[i].src_elt,
sets[i].dest_hash, GET_MODE (dest));
+ /* If this is a constant, insert the constant anchors with the
+ equivalent register-offset expressions using register DEST. */
+ if (targetm.const_anchor
+ && REG_P (dest)
+ && SCALAR_INT_MODE_P (GET_MODE (dest))
+ && GET_CODE (sets[i].src_elt->exp) == CONST_INT)
+ insert_const_anchors (dest, sets[i].src_elt->exp, GET_MODE (dest));
+
elt->in_memory = (MEM_P (sets[i].inner_dest)
&& !MEM_READONLY_P (sets[i].inner_dest));
{
prev = PREV_INSN (prev);
}
- while (prev != bb_head && NOTE_P (prev));
+ while (prev != bb_head && (NOTE_P (prev) || DEBUG_INSN_P (prev)));
/* Do not swap the registers around if the previous instruction
attaches a REG_EQUIV note to REG1.
describe the path.
It is filled with a queue of basic blocks, starting with FIRST_BB
and following a trace through the CFG.
-
+
If all paths starting at FIRST_BB have been followed, or no new path
starting at FIRST_BB can be constructed, this function returns FALSE.
Otherwise, DATA->path is filled and the function returns TRUE indicating
basic_block bb;
edge e;
int path_size;
-
+
SET_BIT (cse_visited_basic_blocks, first_bb->index);
/* See if there is a previous path. */
int path_entry;
/* Scan to end of each basic block in the path. */
- for (path_entry = 0; path_entry < path_size; path_entry++)
+ for (path_entry = 0; path_entry < path_size; path_entry++)
{
basic_block bb;
rtx insn;
edge pointing to that bb. */
if (bb_has_eh_pred (bb))
{
- struct df_ref **def_rec;
+ df_ref *def_rec;
for (def_rec = df_get_artificial_defs (bb->index); *def_rec; def_rec++)
{
- struct df_ref *def = *def_rec;
+ df_ref def = *def_rec;
if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
invalidate (DF_REF_REG (def), GET_MODE (DF_REF_REG (def)));
}
FIXME: This is a real kludge and needs to be done some other
way. */
- if (INSN_P (insn)
+ if (NONDEBUG_INSN_P (insn)
&& num_insns++ > PARAM_VALUE (PARAM_MAX_CSE_INSNS))
{
flush_hash_table ();
incr);
return;
+ case DEBUG_INSN:
+ return;
+
case CALL_INSN:
case INSN:
case JUMP_INSN:
- /* We expect dest to be NULL_RTX here. If the insn may trap, mark
- this fact by setting DEST to pc_rtx. */
- if (flag_non_call_exceptions && may_trap_p (PATTERN (x)))
+ /* We expect dest to be NULL_RTX here. If the insn may trap, mark
+ this fact by setting DEST to pc_rtx. */
+ if (insn_could_throw_p (x))
dest = pc_rtx;
if (code == CALL_INSN)
count_reg_usage (CALL_INSN_FUNCTION_USAGE (x), counts, dest, incr);
}
}
\f
+/* Return true if a register is dead. Can be used in for_each_rtx. */
+
+static int
+is_dead_reg (rtx *loc, void *data)
+{
+ rtx x = *loc;
+ int *counts = (int *)data;
+
+ return (REG_P (x)
+ && REGNO (x) >= FIRST_PSEUDO_REGISTER
+ && counts[REGNO (x)] == 0);
+}
+
/* Return true if set is live. */
static bool
set_live_p (rtx set, rtx insn ATTRIBUTE_UNUSED, /* Only used with HAVE_cc0. */
|| !reg_referenced_p (cc0_rtx, PATTERN (tem))))
return false;
#endif
- else if (!REG_P (SET_DEST (set))
- || REGNO (SET_DEST (set)) < FIRST_PSEUDO_REGISTER
- || counts[REGNO (SET_DEST (set))] != 0
+ else if (!is_dead_reg (&SET_DEST (set), counts)
|| side_effects_p (SET_SRC (set)))
return true;
return false;
insn_live_p (rtx insn, int *counts)
{
int i;
- if (flag_non_call_exceptions && may_trap_p (PATTERN (insn)))
+ if (insn_could_throw_p (insn))
return true;
else if (GET_CODE (PATTERN (insn)) == SET)
return set_live_p (PATTERN (insn), insn, counts);
}
return false;
}
+ else if (DEBUG_INSN_P (insn))
+ {
+ rtx next;
+
+ for (next = NEXT_INSN (insn); next; next = NEXT_INSN (next))
+ if (NOTE_P (next))
+ continue;
+ else if (!DEBUG_INSN_P (next))
+ return true;
+ else if (INSN_VAR_LOCATION_DECL (insn) == INSN_VAR_LOCATION_DECL (next))
+ return false;
+
+ /* If this debug insn references a dead register, drop the
+ location expression for now. ??? We could try to find the
+ def and see if propagation is possible. */
+ if (for_each_rtx (&INSN_VAR_LOCATION_LOC (insn), is_dead_reg, counts))
+ {
+ INSN_VAR_LOCATION_LOC (insn) = gen_rtx_UNKNOWN_VAR_LOC ();
+ df_insn_rescan (insn);
+ }
+
+ return true;
+ }
else
return true;
}
&& GET_MODE (*loc) != GET_MODE (args->newreg))
{
validate_change (args->insn, loc, args->newreg, 1);
-
+
return -1;
}
return 0;
args.insn = insn;
args.newreg = newreg;
-
+
for_each_rtx (&PATTERN (insn), cse_change_cc_mode, &args);
for_each_rtx (®_NOTES (insn), cse_change_cc_mode, &args);
-
+
/* If the following assertion was triggered, there is most probably
something wrong with the cc_modes_compatible back end function.
CC modes only can be considered compatible if the insn - with the mode
permitted to change the mode of CC_SRC to a compatible mode. This
returns VOIDmode if no equivalent assignments were found.
Otherwise it returns the mode which CC_SRC should wind up with.
+ ORIG_BB should be the same as BB in the outermost cse_cc_succs call,
+ but is passed unmodified down to recursive calls in order to prevent
+ endless recursion.
The main complexity in this function is handling the mode issues.
We may have more than one duplicate which we can eliminate, and we
try to find a mode which will work for multiple duplicates. */
static enum machine_mode
-cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
+cse_cc_succs (basic_block bb, basic_block orig_bb, rtx cc_reg, rtx cc_src,
+ bool can_change_mode)
{
bool found_equiv;
enum machine_mode mode;
continue;
if (EDGE_COUNT (e->dest->preds) != 1
- || e->dest == EXIT_BLOCK_PTR)
+ || e->dest == EXIT_BLOCK_PTR
+ /* Avoid endless recursion on unreachable blocks. */
+ || e->dest == orig_bb)
continue;
end = NEXT_INSN (BB_END (e->dest));
XEXP (SET_SRC (set), 0))
&& rtx_equal_p (XEXP (cc_src, 1),
XEXP (SET_SRC (set), 1)))
-
+
{
comp_mode = targetm.cc_modes_compatible (mode, set_mode);
if (comp_mode != VOIDmode
{
enum machine_mode submode;
- submode = cse_cc_succs (e->dest, cc_reg, cc_src, false);
+ submode = cse_cc_succs (e->dest, orig_bb, cc_reg, cc_src, false);
if (submode != VOIDmode)
{
gcc_assert (submode == mode);
the basic block. */
orig_mode = GET_MODE (cc_src);
- mode = cse_cc_succs (bb, cc_reg, cc_src, true);
+ mode = cse_cc_succs (bb, bb, cc_reg, cc_src, true);
if (mode != VOIDmode)
{
gcc_assert (mode == GET_MODE (cc_src));
{
RTL_PASS,
"cse1", /* name */
- gate_handle_cse, /* gate */
- rest_of_handle_cse, /* execute */
+ gate_handle_cse, /* gate */
+ rest_of_handle_cse, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
{
RTL_PASS,
"cse2", /* name */
- gate_handle_cse2, /* gate */
- rest_of_handle_cse2, /* execute */
+ gate_handle_cse2, /* gate */
+ rest_of_handle_cse2, /* execute */
NULL, /* sub */
NULL, /* next */
0, /* static_pass_number */
}
};
+static bool
+gate_handle_cse_after_global_opts (void)
+{
+ return optimize > 0 && flag_rerun_cse_after_global_opts;
+}
+
+/* Run second CSE pass after loop optimizations. */
+static unsigned int
+rest_of_handle_cse_after_global_opts (void)
+{
+ int save_cfj;
+ int tem;
+
+ /* We only want to do local CSE, so don't follow jumps. */
+ save_cfj = flag_cse_follow_jumps;
+ flag_cse_follow_jumps = 0;
+
+ rebuild_jump_labels (get_insns ());
+ tem = cse_main (get_insns (), max_reg_num ());
+ purge_all_dead_edges ();
+ delete_trivially_dead_insns (get_insns (), max_reg_num ());
+
+ cse_not_expected = !flag_rerun_cse_after_loop;
+
+ /* If cse altered any jumps, rerun jump opts to clean things up. */
+ if (tem == 2)
+ {
+ timevar_push (TV_JUMP);
+ rebuild_jump_labels (get_insns ());
+ cleanup_cfg (0);
+ timevar_pop (TV_JUMP);
+ }
+ else if (tem == 1)
+ cleanup_cfg (0);
+
+ flag_cse_follow_jumps = save_cfj;
+ return 0;
+}
+
+struct rtl_opt_pass pass_cse_after_global_opts =
+{
+ {
+ RTL_PASS,
+ "cse_local", /* name */
+ gate_handle_cse_after_global_opts, /* gate */
+ rest_of_handle_cse_after_global_opts, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_CSE, /* 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_verify_flow /* todo_flags_finish */
+ }
+};
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