/* Common subexpression elimination for GNU compiler.
Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
- 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
This file is part of GCC.
#include "system.h"
#include "coretypes.h"
#include "tm.h"
-
#include "rtl.h"
#include "tm_p.h"
-#include "regs.h"
#include "hard-reg-set.h"
+#include "regs.h"
#include "basic-block.h"
#include "flags.h"
#include "real.h"
/* The table of all qtys, indexed by qty number. */
static struct qty_table_elem *qty_table;
+/* Structure used to pass arguments via for_each_rtx to function
+ cse_change_cc_mode. */
+struct change_cc_mode_args
+{
+ rtx insn;
+ rtx newreg;
+};
+
#ifdef HAVE_cc0
/* For machines that have a CC0, we do not record its value in the hash
table since its use is guaranteed to be the insn immediately following
static int do_not_record;
-#ifdef LOAD_EXTEND_OP
-
-/* Scratch rtl used when looking for load-extended copy of a MEM. */
-static rtx memory_extend_rtx;
-#endif
-
/* canon_hash stores 1 in hash_arg_in_memory
if it notices a reference to memory within the expression being hashed. */
of 0. Next come pseudos with a cost of one and other hard registers with
a cost of 2. Aside from these special cases, call `rtx_cost'. */
-#define CHEAP_REGNO(N) \
- ((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \
- || (N) == STACK_POINTER_REGNUM || (N) == ARG_POINTER_REGNUM \
- || ((N) >= FIRST_VIRTUAL_REGISTER && (N) <= LAST_VIRTUAL_REGISTER) \
- || ((N) < FIRST_PSEUDO_REGISTER \
+#define CHEAP_REGNO(N) \
+ (REGNO_PTR_FRAME_P(N) \
+ || (HARD_REGISTER_NUM_P (N) \
&& FIXED_REGNO_P (N) && REGNO_REG_CLASS (N) != NO_REGS))
#define COST(X) (REG_P (X) ? 0 : notreg_cost (X, SET))
static bool set_live_p (rtx, rtx, int *);
static bool dead_libcall_p (rtx, int *);
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);
\f
return cost;
}
+/* Returns a canonical version of X for the address, from the point of view,
+ that all multiplications are represented as MULT instead of the multiply
+ by a power of 2 being represented as ASHIFT. */
+
+static rtx
+canon_for_address (rtx x)
+{
+ enum rtx_code code;
+ enum machine_mode mode;
+ rtx new = 0;
+ int i;
+ const char *fmt;
+
+ if (!x)
+ return x;
+
+ code = GET_CODE (x);
+ mode = GET_MODE (x);
+
+ switch (code)
+ {
+ case ASHIFT:
+ if (GET_CODE (XEXP (x, 1)) == CONST_INT
+ && INTVAL (XEXP (x, 1)) < GET_MODE_BITSIZE (mode)
+ && INTVAL (XEXP (x, 1)) >= 0)
+ {
+ new = canon_for_address (XEXP (x, 0));
+ new = gen_rtx_MULT (mode, new,
+ gen_int_mode ((HOST_WIDE_INT) 1
+ << INTVAL (XEXP (x, 1)),
+ mode));
+ }
+ break;
+ default:
+ break;
+
+ }
+ if (new)
+ return new;
+
+ /* Now recursively process each operand of this operation. */
+ fmt = GET_RTX_FORMAT (code);
+ for (i = 0; i < GET_RTX_LENGTH (code); i++)
+ if (fmt[i] == 'e')
+ {
+ new = canon_for_address (XEXP (x, i));
+ XEXP (x, i) = new;
+ }
+ return x;
+}
+
/* Return a negative value if an rtx A, whose costs are given by COST_A
and REGCOST_A, is more desirable than an rtx B.
Return a positive value if A is less desirable, or 0 if the two are
rtx new = simplify_gen_binary (GET_CODE (*loc), Pmode,
p->exp, op1);
int new_cost;
+
+ /* Get the canonical version of the address so we can accept
+ more. */
+ new = canon_for_address (new);
+
new_cost = address_cost (new, mode);
if (new_cost < best_addr_cost
constant, set CONST_ARG0 and CONST_ARG1 appropriately. We needn't
do anything if both operands are already known to be constant. */
+ /* ??? Vector mode comparisons are not supported yet. */
+ if (VECTOR_MODE_P (mode))
+ break;
+
if (const_arg0 == 0 || const_arg1 == 0)
{
struct table_elt *p0, *p1;
record_jump_cond (code, mode, op0, op1, reversed_nonequality);
}
+/* Yet another form of subreg creation. In this case, we want something in
+ MODE, and we should assume OP has MODE iff it is naturally modeless. */
+
+static rtx
+record_jump_cond_subreg (enum machine_mode mode, rtx op)
+{
+ enum machine_mode op_mode = GET_MODE (op);
+ if (op_mode == mode || op_mode == VOIDmode)
+ return op;
+ return lowpart_subreg (mode, op, op_mode);
+}
+
/* We know that comparison CODE applied to OP0 and OP1 in MODE is true.
REVERSED_NONEQUALITY is nonzero if CODE had to be swapped.
Make any useful entries we can with that information. Called from
> GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)))))
{
enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0));
- rtx tem = gen_lowpart (inner_mode, op1);
-
- record_jump_cond (code, mode, SUBREG_REG (op0),
- tem ? tem : gen_rtx_SUBREG (inner_mode, op1, 0),
- reversed_nonequality);
+ rtx tem = record_jump_cond_subreg (inner_mode, op1);
+ if (tem)
+ record_jump_cond (code, mode, SUBREG_REG (op0), tem,
+ reversed_nonequality);
}
if (code == EQ && GET_CODE (op1) == SUBREG
> GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1)))))
{
enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1));
- rtx tem = gen_lowpart (inner_mode, op0);
-
- record_jump_cond (code, mode, SUBREG_REG (op1),
- tem ? tem : gen_rtx_SUBREG (inner_mode, op0, 0),
- reversed_nonequality);
+ rtx tem = record_jump_cond_subreg (inner_mode, op0);
+ if (tem)
+ record_jump_cond (code, mode, SUBREG_REG (op1), tem,
+ reversed_nonequality);
}
/* Similarly, if this is an NE comparison, and either is a SUBREG
< GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)))))
{
enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0));
- rtx tem = gen_lowpart (inner_mode, op1);
-
- record_jump_cond (code, mode, SUBREG_REG (op0),
- tem ? tem : gen_rtx_SUBREG (inner_mode, op1, 0),
- reversed_nonequality);
+ rtx tem = record_jump_cond_subreg (inner_mode, op1);
+ if (tem)
+ record_jump_cond (code, mode, SUBREG_REG (op0), tem,
+ reversed_nonequality);
}
if (code == NE && GET_CODE (op1) == SUBREG
< GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1)))))
{
enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1));
- rtx tem = gen_lowpart (inner_mode, op0);
-
- record_jump_cond (code, mode, SUBREG_REG (op1),
- tem ? tem : gen_rtx_SUBREG (inner_mode, op0, 0),
- reversed_nonequality);
+ rtx tem = record_jump_cond_subreg (inner_mode, op0);
+ if (tem)
+ record_jump_cond (code, mode, SUBREG_REG (op1), tem,
+ reversed_nonequality);
}
/* Hash both operands. */
else
SET_SRC (sets[i].rtl) = new;
- if (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT)
+ if (GET_CODE (dest) == ZERO_EXTRACT)
{
validate_change (insn, &XEXP (dest, 1),
canon_reg (XEXP (dest, 1), insn), 1);
canon_reg (XEXP (dest, 2), insn), 1);
}
- while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
+ while (GET_CODE (dest) == SUBREG
|| GET_CODE (dest) == ZERO_EXTRACT
- || GET_CODE (dest) == SIGN_EXTRACT)
+ || GET_CODE (dest) == STRICT_LOW_PART)
dest = XEXP (dest, 0);
if (MEM_P (dest))
causes later instructions to be mis-optimized. */
/* If storing a constant in a bitfield, pre-truncate the constant
so we will be able to record it later. */
- if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT
- || GET_CODE (SET_DEST (sets[i].rtl)) == SIGN_EXTRACT)
+ if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT)
{
rtx width = XEXP (SET_DEST (sets[i].rtl), 1);
&& MEM_P (src) && ! do_not_record
&& LOAD_EXTEND_OP (mode) != UNKNOWN)
{
+ struct rtx_def memory_extend_buf;
+ rtx memory_extend_rtx = &memory_extend_buf;
enum machine_mode tmode;
/* Set what we are trying to extend and the operation it might
have been extended with. */
+ memset (memory_extend_rtx, 0, sizeof(*memory_extend_rtx));
PUT_CODE (memory_extend_rtx, LOAD_EXTEND_OP (mode));
XEXP (memory_extend_rtx, 0) = src;
/* Now deal with the destination. */
do_not_record = 0;
- /* Look within any SIGN_EXTRACT or ZERO_EXTRACT
- to the MEM or REG within it. */
- while (GET_CODE (dest) == SIGN_EXTRACT
+ /* Look within any ZERO_EXTRACT to the MEM or REG within it. */
+ while (GET_CODE (dest) == SUBREG
|| GET_CODE (dest) == ZERO_EXTRACT
- || GET_CODE (dest) == SUBREG
|| GET_CODE (dest) == STRICT_LOW_PART)
dest = XEXP (dest, 0);
because the value in it after the store
may not equal what was stored, due to truncation. */
- if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT
- || GET_CODE (SET_DEST (sets[i].rtl)) == SIGN_EXTRACT)
+ if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT)
{
rtx width = XEXP (SET_DEST (sets[i].rtl), 1);
if (REG_P (dest) || GET_CODE (dest) == SUBREG)
invalidate (dest, VOIDmode);
else if (MEM_P (dest))
- {
- /* Outgoing arguments for a libcall don't
- affect any recorded expressions. */
- if (! libcall_insn || insn == libcall_insn)
- invalidate (dest, VOIDmode);
- }
+ invalidate (dest, VOIDmode);
else if (GET_CODE (dest) == STRICT_LOW_PART
|| GET_CODE (dest) == ZERO_EXTRACT)
invalidate (XEXP (dest, 0), GET_MODE (dest));
if (REG_P (dest) || GET_CODE (dest) == SUBREG)
invalidate (dest, VOIDmode);
else if (MEM_P (dest))
- {
- /* Outgoing arguments for a libcall don't
- affect any recorded expressions. */
- if (! libcall_insn || insn == libcall_insn)
- invalidate (dest, VOIDmode);
- }
+ invalidate (dest, VOIDmode);
else if (GET_CODE (dest) == STRICT_LOW_PART
|| GET_CODE (dest) == ZERO_EXTRACT)
invalidate (XEXP (dest, 0), GET_MODE (dest));
reg_eqv_table = xmalloc (nregs * sizeof (struct reg_eqv_elem));
-#ifdef LOAD_EXTEND_OP
-
- /* Allocate scratch rtl here. cse_insn will fill in the memory reference
- and change the code and mode as appropriate. */
- memory_extend_rtx = gen_rtx_ZERO_EXTEND (VOIDmode, NULL_RTX);
-#endif
-
/* Reset the counter indicating how many elements have been made
thus far. */
n_elements_made = 0;
/* Process a single basic block. FROM and TO and the limits of the basic
block. NEXT_BRANCH points to the branch path when following jumps or
- a null path when not following jumps.
-
- AROUND_LOOP is nonzero if we are to try to cse around to the start of a
- loop. This is true when we are being called for the last time on a
- block and this CSE pass is before loop.c. */
+ a null path when not following jumps. */
static rtx
cse_basic_block (rtx from, rtx to, struct branch_path *next_branch)
static int
cse_change_cc_mode (rtx *loc, void *data)
{
- rtx newreg = (rtx) data;
+ struct change_cc_mode_args* args = (struct change_cc_mode_args*)data;
if (*loc
&& REG_P (*loc)
- && REGNO (*loc) == REGNO (newreg)
- && GET_MODE (*loc) != GET_MODE (newreg))
+ && REGNO (*loc) == REGNO (args->newreg)
+ && GET_MODE (*loc) != GET_MODE (args->newreg))
{
- *loc = newreg;
+ validate_change (args->insn, loc, args->newreg, 1);
+
return -1;
}
return 0;
}
/* Change the mode of any reference to the register REGNO (NEWREG) to
+ GET_MODE (NEWREG) in INSN. */
+
+static void
+cse_change_cc_mode_insn (rtx insn, rtx newreg)
+{
+ struct change_cc_mode_args args;
+ int success;
+
+ if (!INSN_P (insn))
+ return;
+
+ 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
+ replaced by any of the compatible modes - can still be recognized. */
+ success = apply_change_group ();
+ gcc_assert (success);
+}
+
+/* Change the mode of any reference to the register REGNO (NEWREG) to
GET_MODE (NEWREG), starting at START. Stop before END. Stop at
any instruction which modifies NEWREG. */
if (reg_set_p (newreg, insn))
return;
- for_each_rtx (&PATTERN (insn), cse_change_cc_mode, newreg);
- for_each_rtx (®_NOTES (insn), cse_change_cc_mode, newreg);
+ cse_change_cc_mode_insn (insn, newreg);
}
}
{
gcc_assert (can_change_mode);
mode = comp_mode;
+
+ /* The modified insn will be re-recognized later. */
PUT_MODE (cc_src, mode);
}
}
{
rtx newreg = gen_rtx_REG (mode, REGNO (cc_reg));
- /* Change the mode of CC_REG in CC_SRC_INSN to
- GET_MODE (NEWREG). */
- for_each_rtx (&PATTERN (cc_src_insn), cse_change_cc_mode,
- newreg);
- for_each_rtx (®_NOTES (cc_src_insn), cse_change_cc_mode,
- newreg);
+ cse_change_cc_mode_insn (cc_src_insn, newreg);
/* Do the same in the following insns that use the
current value of CC_REG within BB. */
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