};
/* A table of cse_reg_info indexed by register numbers. */
-struct cse_reg_info *cse_reg_info_table;
+static struct cse_reg_info *cse_reg_info_table;
/* The size of the above table. */
static unsigned int cse_reg_info_table_size;
}
/* Reallocate the table with NEW_SIZE entries. */
- cse_reg_info_table = xrealloc (cse_reg_info_table,
- (sizeof (struct cse_reg_info)
- * new_size));
+ if (cse_reg_info_table)
+ free (cse_reg_info_table);
+ cse_reg_info_table = xmalloc (sizeof (struct cse_reg_info)
+ * new_size);
cse_reg_info_table_size = new_size;
+ cse_reg_info_table_first_uninitialized = 0;
}
/* Do we have all of the first NREGS entries initialized? */
if (REG_P (classp->exp)
&& GET_MODE (classp->exp) == GET_MODE (x))
{
- make_regs_eqv (regno, REGNO (classp->exp));
+ unsigned c_regno = REGNO (classp->exp);
+
+ gcc_assert (REGNO_QTY_VALID_P (c_regno));
+
+ /* Suppose that 5 is hard reg and 100 and 101 are
+ pseudos. Consider
+
+ (set (reg:si 100) (reg:si 5))
+ (set (reg:si 5) (reg:si 100))
+ (set (reg:di 101) (reg:di 5))
+
+ We would now set REG_QTY (101) = REG_QTY (5), but the
+ entry for 5 is in SImode. When we use this later in
+ copy propagation, we get the register in wrong mode. */
+ if (qty_table[REG_QTY (c_regno)].mode != GET_MODE (x))
+ continue;
+
+ make_regs_eqv (regno, c_regno);
return 1;
}
be valid and produce better code. */
if (!REG_P (addr))
{
- rtx folded = fold_rtx (addr, NULL_RTX);
+ rtx folded = canon_for_address (fold_rtx (addr, NULL_RTX));
+
if (folded != addr)
{
int addr_folded_cost = address_cost (folded, mode);
int new_cost;
/* Get the canonical version of the address so we can accept
- more. */
+ more. */
new = canon_for_address (new);
new_cost = address_cost (new, mode);
return code;
}
\f
+/* Fold SUBREG. */
+
+static rtx
+fold_rtx_subreg (rtx x, rtx insn)
+{
+ enum machine_mode mode = GET_MODE (x);
+ rtx folded_arg0;
+ rtx const_arg0;
+ rtx new;
+
+ /* See if we previously assigned a constant value to this SUBREG. */
+ if ((new = lookup_as_function (x, CONST_INT)) != 0
+ || (new = lookup_as_function (x, CONST_DOUBLE)) != 0)
+ return new;
+
+ /* If this is a paradoxical SUBREG, we have no idea what value the
+ extra bits would have. However, if the operand is equivalent to
+ a SUBREG whose operand is the same as our mode, and all the modes
+ are within a word, we can just use the inner operand because
+ these SUBREGs just say how to treat the register.
+
+ Similarly if we find an integer constant. */
+
+ if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
+ {
+ enum machine_mode imode = GET_MODE (SUBREG_REG (x));
+ struct table_elt *elt;
+
+ if (GET_MODE_SIZE (mode) <= UNITS_PER_WORD
+ && GET_MODE_SIZE (imode) <= UNITS_PER_WORD
+ && (elt = lookup (SUBREG_REG (x), HASH (SUBREG_REG (x), imode),
+ imode)) != 0)
+ for (elt = elt->first_same_value; elt; elt = elt->next_same_value)
+ {
+ if (CONSTANT_P (elt->exp)
+ && GET_MODE (elt->exp) == VOIDmode)
+ return elt->exp;
+
+ if (GET_CODE (elt->exp) == SUBREG
+ && GET_MODE (SUBREG_REG (elt->exp)) == mode
+ && exp_equiv_p (elt->exp, elt->exp, 1, false))
+ return copy_rtx (SUBREG_REG (elt->exp));
+ }
+
+ return x;
+ }
+
+ /* Fold SUBREG_REG. If it changed, see if we can simplify the
+ SUBREG. We might be able to if the SUBREG is extracting a single
+ word in an integral mode or extracting the low part. */
+
+ folded_arg0 = fold_rtx (SUBREG_REG (x), insn);
+ const_arg0 = equiv_constant (folded_arg0);
+ if (const_arg0)
+ folded_arg0 = const_arg0;
+
+ if (folded_arg0 != SUBREG_REG (x))
+ {
+ new = simplify_subreg (mode, folded_arg0,
+ GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
+ if (new)
+ return new;
+ }
+
+ if (REG_P (folded_arg0)
+ && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (folded_arg0)))
+ {
+ struct table_elt *elt;
+
+ elt = lookup (folded_arg0,
+ HASH (folded_arg0, GET_MODE (folded_arg0)),
+ GET_MODE (folded_arg0));
+
+ if (elt)
+ elt = elt->first_same_value;
+
+ if (subreg_lowpart_p (x))
+ /* If this is a narrowing SUBREG and our operand is a REG, see
+ if we can find an equivalence for REG that is an arithmetic
+ operation in a wider mode where both operands are
+ paradoxical SUBREGs from objects of our result mode. In
+ that case, we couldn-t report an equivalent value for that
+ operation, since we don't know what the extra bits will be.
+ But we can find an equivalence for this SUBREG by folding
+ that operation in the narrow mode. This allows us to fold
+ arithmetic in narrow modes when the machine only supports
+ word-sized arithmetic.
+
+ Also look for a case where we have a SUBREG whose operand
+ is the same as our result. If both modes are smaller than
+ a word, we are simply interpreting a register in different
+ modes and we can use the inner value. */
+
+ for (; elt; elt = elt->next_same_value)
+ {
+ enum rtx_code eltcode = GET_CODE (elt->exp);
+
+ /* Just check for unary and binary operations. */
+ if (UNARY_P (elt->exp)
+ && eltcode != SIGN_EXTEND
+ && eltcode != ZERO_EXTEND
+ && GET_CODE (XEXP (elt->exp, 0)) == SUBREG
+ && GET_MODE (SUBREG_REG (XEXP (elt->exp, 0))) == mode
+ && (GET_MODE_CLASS (mode)
+ == GET_MODE_CLASS (GET_MODE (XEXP (elt->exp, 0)))))
+ {
+ rtx op0 = SUBREG_REG (XEXP (elt->exp, 0));
+
+ if (!REG_P (op0) && ! CONSTANT_P (op0))
+ op0 = fold_rtx (op0, NULL_RTX);
+
+ op0 = equiv_constant (op0);
+ if (op0)
+ new = simplify_unary_operation (GET_CODE (elt->exp), mode,
+ op0, mode);
+ }
+ else if (ARITHMETIC_P (elt->exp)
+ && eltcode != DIV && eltcode != MOD
+ && eltcode != UDIV && eltcode != UMOD
+ && eltcode != ASHIFTRT && eltcode != LSHIFTRT
+ && eltcode != ROTATE && eltcode != ROTATERT
+ && ((GET_CODE (XEXP (elt->exp, 0)) == SUBREG
+ && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 0)))
+ == mode))
+ || CONSTANT_P (XEXP (elt->exp, 0)))
+ && ((GET_CODE (XEXP (elt->exp, 1)) == SUBREG
+ && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 1)))
+ == mode))
+ || CONSTANT_P (XEXP (elt->exp, 1))))
+ {
+ rtx op0 = gen_lowpart_common (mode, XEXP (elt->exp, 0));
+ rtx op1 = gen_lowpart_common (mode, XEXP (elt->exp, 1));
+
+ if (op0 && !REG_P (op0) && ! CONSTANT_P (op0))
+ op0 = fold_rtx (op0, NULL_RTX);
+
+ if (op0)
+ op0 = equiv_constant (op0);
+
+ if (op1 && !REG_P (op1) && ! CONSTANT_P (op1))
+ op1 = fold_rtx (op1, NULL_RTX);
+
+ if (op1)
+ op1 = equiv_constant (op1);
+
+ /* If we are looking for the low SImode part of
+ (ashift:DI c (const_int 32)), it doesn't work to
+ compute that in SImode, because a 32-bit shift in
+ SImode is unpredictable. We know the value is
+ 0. */
+ if (op0 && op1
+ && GET_CODE (elt->exp) == ASHIFT
+ && GET_CODE (op1) == CONST_INT
+ && INTVAL (op1) >= GET_MODE_BITSIZE (mode))
+ {
+ if (INTVAL (op1)
+ < GET_MODE_BITSIZE (GET_MODE (elt->exp)))
+ /* If the count fits in the inner mode's width,
+ but exceeds the outer mode's width, the value
+ will get truncated to 0 by the subreg. */
+ new = CONST0_RTX (mode);
+ else
+ /* If the count exceeds even the inner mode's width,
+ don't fold this expression. */
+ new = 0;
+ }
+ else if (op0 && op1)
+ new = simplify_binary_operation (GET_CODE (elt->exp),
+ mode, op0, op1);
+ }
+
+ else if (GET_CODE (elt->exp) == SUBREG
+ && GET_MODE (SUBREG_REG (elt->exp)) == mode
+ && (GET_MODE_SIZE (GET_MODE (folded_arg0))
+ <= UNITS_PER_WORD)
+ && exp_equiv_p (elt->exp, elt->exp, 1, false))
+ new = copy_rtx (SUBREG_REG (elt->exp));
+
+ if (new)
+ return new;
+ }
+ else
+ /* A SUBREG resulting from a zero extension may fold to zero
+ if it extracts higher bits than the ZERO_EXTEND's source
+ bits. FIXME: if combine tried to, er, combine these
+ instructions, this transformation may be moved to
+ simplify_subreg. */
+ for (; elt; elt = elt->next_same_value)
+ {
+ if (GET_CODE (elt->exp) == ZERO_EXTEND
+ && subreg_lsb (x)
+ >= GET_MODE_BITSIZE (GET_MODE (XEXP (elt->exp, 0))))
+ return CONST0_RTX (mode);
+ }
+ }
+
+ return x;
+}
+
+/* Fold MEM. */
+
+static rtx
+fold_rtx_mem (rtx x, rtx insn)
+{
+ enum machine_mode mode = GET_MODE (x);
+ rtx new;
+
+ /* If we are not actually processing an insn, don't try to find the
+ best address. Not only don't we care, but we could modify the
+ MEM in an invalid way since we have no insn to validate
+ against. */
+ if (insn != 0)
+ find_best_addr (insn, &XEXP (x, 0), mode);
+
+ {
+ /* Even if we don't fold in the insn itself, we can safely do so
+ here, in hopes of getting a constant. */
+ rtx addr = fold_rtx (XEXP (x, 0), NULL_RTX);
+ rtx base = 0;
+ HOST_WIDE_INT offset = 0;
+
+ if (REG_P (addr)
+ && REGNO_QTY_VALID_P (REGNO (addr)))
+ {
+ int addr_q = REG_QTY (REGNO (addr));
+ struct qty_table_elem *addr_ent = &qty_table[addr_q];
+
+ if (GET_MODE (addr) == addr_ent->mode
+ && addr_ent->const_rtx != NULL_RTX)
+ addr = addr_ent->const_rtx;
+ }
+
+ /* If address is constant, split it into a base and integer
+ offset. */
+ if (GET_CODE (addr) == SYMBOL_REF || GET_CODE (addr) == LABEL_REF)
+ base = addr;
+ else if (GET_CODE (addr) == CONST && GET_CODE (XEXP (addr, 0)) == PLUS
+ && GET_CODE (XEXP (XEXP (addr, 0), 1)) == CONST_INT)
+ {
+ base = XEXP (XEXP (addr, 0), 0);
+ offset = INTVAL (XEXP (XEXP (addr, 0), 1));
+ }
+ else if (GET_CODE (addr) == LO_SUM
+ && GET_CODE (XEXP (addr, 1)) == SYMBOL_REF)
+ base = XEXP (addr, 1);
+
+ /* If this is a constant pool reference, we can fold it into its
+ constant to allow better value tracking. */
+ if (base && GET_CODE (base) == SYMBOL_REF
+ && CONSTANT_POOL_ADDRESS_P (base))
+ {
+ rtx constant = get_pool_constant (base);
+ enum machine_mode const_mode = get_pool_mode (base);
+ rtx new;
+
+ if (CONSTANT_P (constant) && GET_CODE (constant) != CONST_INT)
+ {
+ constant_pool_entries_cost = COST (constant);
+ constant_pool_entries_regcost = approx_reg_cost (constant);
+ }
+
+ /* If we are loading the full constant, we have an
+ equivalence. */
+ if (offset == 0 && mode == const_mode)
+ return constant;
+
+ /* If this actually isn't a constant (weird!), we can't do
+ anything. Otherwise, handle the two most common cases:
+ extracting a word from a multi-word constant, and
+ extracting the low-order bits. Other cases don't seem
+ common enough to worry about. */
+ if (! CONSTANT_P (constant))
+ return x;
+
+ if (GET_MODE_CLASS (mode) == MODE_INT
+ && GET_MODE_SIZE (mode) == UNITS_PER_WORD
+ && offset % UNITS_PER_WORD == 0
+ && (new = operand_subword (constant,
+ offset / UNITS_PER_WORD,
+ 0, const_mode)) != 0)
+ return new;
+
+ if (((BYTES_BIG_ENDIAN
+ && offset == GET_MODE_SIZE (GET_MODE (constant)) - 1)
+ || (! BYTES_BIG_ENDIAN && offset == 0))
+ && (new = gen_lowpart (mode, constant)) != 0)
+ return new;
+ }
+
+ /* If this is a reference to a label at a known position in a jump
+ table, we also know its value. */
+ if (base && GET_CODE (base) == LABEL_REF)
+ {
+ rtx label = XEXP (base, 0);
+ rtx table_insn = NEXT_INSN (label);
+
+ if (table_insn && JUMP_P (table_insn)
+ && GET_CODE (PATTERN (table_insn)) == ADDR_VEC)
+ {
+ rtx table = PATTERN (table_insn);
+
+ if (offset >= 0
+ && (offset / GET_MODE_SIZE (GET_MODE (table))
+ < XVECLEN (table, 0)))
+ {
+ rtx label = XVECEXP
+ (table, 0, offset / GET_MODE_SIZE (GET_MODE (table)));
+ rtx set;
+
+ /* If we have an insn that loads the label from the
+ jumptable into a reg, we don't want to set the reg
+ to the label, because this may cause a reference to
+ the label to remain after the label is removed in
+ some very obscure cases (PR middle-end/18628). */
+ if (!insn)
+ return label;
+
+ set = single_set (insn);
+
+ if (! set || SET_SRC (set) != x)
+ return x;
+
+ /* If it's a jump, it's safe to reference the label. */
+ if (SET_DEST (set) == pc_rtx)
+ return label;
+
+ return x;
+ }
+ }
+ if (table_insn && JUMP_P (table_insn)
+ && GET_CODE (PATTERN (table_insn)) == ADDR_DIFF_VEC)
+ {
+ rtx table = PATTERN (table_insn);
+
+ if (offset >= 0
+ && (offset / GET_MODE_SIZE (GET_MODE (table))
+ < XVECLEN (table, 1)))
+ {
+ offset /= GET_MODE_SIZE (GET_MODE (table));
+ new = gen_rtx_MINUS (Pmode, XVECEXP (table, 1, offset),
+ XEXP (table, 0));
+
+ if (GET_MODE (table) != Pmode)
+ new = gen_rtx_TRUNCATE (GET_MODE (table), new);
+
+ /* Indicate this is a constant. This isn't a valid
+ form of CONST, but it will only be used to fold the
+ next insns and then discarded, so it should be
+ safe.
+
+ Note this expression must be explicitly discarded,
+ by cse_insn, else it may end up in a REG_EQUAL note
+ and "escape" to cause problems elsewhere. */
+ return gen_rtx_CONST (GET_MODE (new), new);
+ }
+ }
+ }
+
+ return x;
+ }
+}
+
/* If X is a nontrivial arithmetic operation on an argument
for which a constant value can be determined, return
the result of operating on that value, as a constant.
#endif
case SUBREG:
- /* See if we previously assigned a constant value to this SUBREG. */
- if ((new = lookup_as_function (x, CONST_INT)) != 0
- || (new = lookup_as_function (x, CONST_DOUBLE)) != 0)
- return new;
-
- /* If this is a paradoxical SUBREG, we have no idea what value the
- extra bits would have. However, if the operand is equivalent
- to a SUBREG whose operand is the same as our mode, and all the
- modes are within a word, we can just use the inner operand
- because these SUBREGs just say how to treat the register.
-
- Similarly if we find an integer constant. */
-
- if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
- {
- enum machine_mode imode = GET_MODE (SUBREG_REG (x));
- struct table_elt *elt;
-
- if (GET_MODE_SIZE (mode) <= UNITS_PER_WORD
- && GET_MODE_SIZE (imode) <= UNITS_PER_WORD
- && (elt = lookup (SUBREG_REG (x), HASH (SUBREG_REG (x), imode),
- imode)) != 0)
- for (elt = elt->first_same_value; elt; elt = elt->next_same_value)
- {
- if (CONSTANT_P (elt->exp)
- && GET_MODE (elt->exp) == VOIDmode)
- return elt->exp;
-
- if (GET_CODE (elt->exp) == SUBREG
- && GET_MODE (SUBREG_REG (elt->exp)) == mode
- && exp_equiv_p (elt->exp, elt->exp, 1, false))
- return copy_rtx (SUBREG_REG (elt->exp));
- }
-
- return x;
- }
-
- /* Fold SUBREG_REG. If it changed, see if we can simplify the SUBREG.
- We might be able to if the SUBREG is extracting a single word in an
- integral mode or extracting the low part. */
-
- folded_arg0 = fold_rtx (SUBREG_REG (x), insn);
- const_arg0 = equiv_constant (folded_arg0);
- if (const_arg0)
- folded_arg0 = const_arg0;
-
- if (folded_arg0 != SUBREG_REG (x))
- {
- new = simplify_subreg (mode, folded_arg0,
- GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
- if (new)
- return new;
- }
-
- if (REG_P (folded_arg0)
- && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (folded_arg0)))
- {
- struct table_elt *elt;
-
- elt = lookup (folded_arg0,
- HASH (folded_arg0, GET_MODE (folded_arg0)),
- GET_MODE (folded_arg0));
-
- if (elt)
- elt = elt->first_same_value;
-
- if (subreg_lowpart_p (x))
- /* If this is a narrowing SUBREG and our operand is a REG, see
- if we can find an equivalence for REG that is an arithmetic
- operation in a wider mode where both operands are paradoxical
- SUBREGs from objects of our result mode. In that case, we
- couldn-t report an equivalent value for that operation, since we
- don't know what the extra bits will be. But we can find an
- equivalence for this SUBREG by folding that operation in the
- narrow mode. This allows us to fold arithmetic in narrow modes
- when the machine only supports word-sized arithmetic.
-
- Also look for a case where we have a SUBREG whose operand
- is the same as our result. If both modes are smaller
- than a word, we are simply interpreting a register in
- different modes and we can use the inner value. */
-
- for (; elt; elt = elt->next_same_value)
- {
- enum rtx_code eltcode = GET_CODE (elt->exp);
-
- /* Just check for unary and binary operations. */
- if (UNARY_P (elt->exp)
- && eltcode != SIGN_EXTEND
- && eltcode != ZERO_EXTEND
- && GET_CODE (XEXP (elt->exp, 0)) == SUBREG
- && GET_MODE (SUBREG_REG (XEXP (elt->exp, 0))) == mode
- && (GET_MODE_CLASS (mode)
- == GET_MODE_CLASS (GET_MODE (XEXP (elt->exp, 0)))))
- {
- rtx op0 = SUBREG_REG (XEXP (elt->exp, 0));
-
- if (!REG_P (op0) && ! CONSTANT_P (op0))
- op0 = fold_rtx (op0, NULL_RTX);
-
- op0 = equiv_constant (op0);
- if (op0)
- new = simplify_unary_operation (GET_CODE (elt->exp), mode,
- op0, mode);
- }
- else if (ARITHMETIC_P (elt->exp)
- && eltcode != DIV && eltcode != MOD
- && eltcode != UDIV && eltcode != UMOD
- && eltcode != ASHIFTRT && eltcode != LSHIFTRT
- && eltcode != ROTATE && eltcode != ROTATERT
- && ((GET_CODE (XEXP (elt->exp, 0)) == SUBREG
- && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 0)))
- == mode))
- || CONSTANT_P (XEXP (elt->exp, 0)))
- && ((GET_CODE (XEXP (elt->exp, 1)) == SUBREG
- && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 1)))
- == mode))
- || CONSTANT_P (XEXP (elt->exp, 1))))
- {
- rtx op0 = gen_lowpart_common (mode, XEXP (elt->exp, 0));
- rtx op1 = gen_lowpart_common (mode, XEXP (elt->exp, 1));
-
- if (op0 && !REG_P (op0) && ! CONSTANT_P (op0))
- op0 = fold_rtx (op0, NULL_RTX);
-
- if (op0)
- op0 = equiv_constant (op0);
-
- if (op1 && !REG_P (op1) && ! CONSTANT_P (op1))
- op1 = fold_rtx (op1, NULL_RTX);
-
- if (op1)
- op1 = equiv_constant (op1);
-
- /* If we are looking for the low SImode part of
- (ashift:DI c (const_int 32)), it doesn't work
- to compute that in SImode, because a 32-bit shift
- in SImode is unpredictable. We know the value is 0. */
- if (op0 && op1
- && GET_CODE (elt->exp) == ASHIFT
- && GET_CODE (op1) == CONST_INT
- && INTVAL (op1) >= GET_MODE_BITSIZE (mode))
- {
- if (INTVAL (op1)
- < GET_MODE_BITSIZE (GET_MODE (elt->exp)))
- /* If the count fits in the inner mode's width,
- but exceeds the outer mode's width,
- the value will get truncated to 0
- by the subreg. */
- new = CONST0_RTX (mode);
- else
- /* If the count exceeds even the inner mode's width,
- don't fold this expression. */
- new = 0;
- }
- else if (op0 && op1)
- new = simplify_binary_operation (GET_CODE (elt->exp), mode, op0, op1);
- }
-
- else if (GET_CODE (elt->exp) == SUBREG
- && GET_MODE (SUBREG_REG (elt->exp)) == mode
- && (GET_MODE_SIZE (GET_MODE (folded_arg0))
- <= UNITS_PER_WORD)
- && exp_equiv_p (elt->exp, elt->exp, 1, false))
- new = copy_rtx (SUBREG_REG (elt->exp));
-
- if (new)
- return new;
- }
- else
- /* A SUBREG resulting from a zero extension may fold to zero if
- it extracts higher bits than the ZERO_EXTEND's source bits.
- FIXME: if combine tried to, er, combine these instructions,
- this transformation may be moved to simplify_subreg. */
- for (; elt; elt = elt->next_same_value)
- {
- if (GET_CODE (elt->exp) == ZERO_EXTEND
- && subreg_lsb (x)
- >= GET_MODE_BITSIZE (GET_MODE (XEXP (elt->exp, 0))))
- return CONST0_RTX (mode);
- }
- }
-
- return x;
+ return fold_rtx_subreg (x, insn);
case NOT:
case NEG:
break;
case MEM:
- /* If we are not actually processing an insn, don't try to find the
- best address. Not only don't we care, but we could modify the
- MEM in an invalid way since we have no insn to validate against. */
- if (insn != 0)
- find_best_addr (insn, &XEXP (x, 0), GET_MODE (x));
-
- {
- /* Even if we don't fold in the insn itself,
- we can safely do so here, in hopes of getting a constant. */
- rtx addr = fold_rtx (XEXP (x, 0), NULL_RTX);
- rtx base = 0;
- HOST_WIDE_INT offset = 0;
-
- if (REG_P (addr)
- && REGNO_QTY_VALID_P (REGNO (addr)))
- {
- int addr_q = REG_QTY (REGNO (addr));
- struct qty_table_elem *addr_ent = &qty_table[addr_q];
-
- if (GET_MODE (addr) == addr_ent->mode
- && addr_ent->const_rtx != NULL_RTX)
- addr = addr_ent->const_rtx;
- }
-
- /* If address is constant, split it into a base and integer offset. */
- if (GET_CODE (addr) == SYMBOL_REF || GET_CODE (addr) == LABEL_REF)
- base = addr;
- else if (GET_CODE (addr) == CONST && GET_CODE (XEXP (addr, 0)) == PLUS
- && GET_CODE (XEXP (XEXP (addr, 0), 1)) == CONST_INT)
- {
- base = XEXP (XEXP (addr, 0), 0);
- offset = INTVAL (XEXP (XEXP (addr, 0), 1));
- }
- else if (GET_CODE (addr) == LO_SUM
- && GET_CODE (XEXP (addr, 1)) == SYMBOL_REF)
- base = XEXP (addr, 1);
-
- /* If this is a constant pool reference, we can fold it into its
- constant to allow better value tracking. */
- if (base && GET_CODE (base) == SYMBOL_REF
- && CONSTANT_POOL_ADDRESS_P (base))
- {
- rtx constant = get_pool_constant (base);
- enum machine_mode const_mode = get_pool_mode (base);
- rtx new;
-
- if (CONSTANT_P (constant) && GET_CODE (constant) != CONST_INT)
- {
- constant_pool_entries_cost = COST (constant);
- constant_pool_entries_regcost = approx_reg_cost (constant);
- }
-
- /* If we are loading the full constant, we have an equivalence. */
- if (offset == 0 && mode == const_mode)
- return constant;
-
- /* If this actually isn't a constant (weird!), we can't do
- anything. Otherwise, handle the two most common cases:
- extracting a word from a multi-word constant, and extracting
- the low-order bits. Other cases don't seem common enough to
- worry about. */
- if (! CONSTANT_P (constant))
- return x;
-
- if (GET_MODE_CLASS (mode) == MODE_INT
- && GET_MODE_SIZE (mode) == UNITS_PER_WORD
- && offset % UNITS_PER_WORD == 0
- && (new = operand_subword (constant,
- offset / UNITS_PER_WORD,
- 0, const_mode)) != 0)
- return new;
-
- if (((BYTES_BIG_ENDIAN
- && offset == GET_MODE_SIZE (GET_MODE (constant)) - 1)
- || (! BYTES_BIG_ENDIAN && offset == 0))
- && (new = gen_lowpart (mode, constant)) != 0)
- return new;
- }
-
- /* If this is a reference to a label at a known position in a jump
- table, we also know its value. */
- if (base && GET_CODE (base) == LABEL_REF)
- {
- rtx label = XEXP (base, 0);
- rtx table_insn = NEXT_INSN (label);
-
- if (table_insn && JUMP_P (table_insn)
- && GET_CODE (PATTERN (table_insn)) == ADDR_VEC)
- {
- rtx table = PATTERN (table_insn);
-
- if (offset >= 0
- && (offset / GET_MODE_SIZE (GET_MODE (table))
- < XVECLEN (table, 0)))
- return XVECEXP (table, 0,
- offset / GET_MODE_SIZE (GET_MODE (table)));
- }
- if (table_insn && JUMP_P (table_insn)
- && GET_CODE (PATTERN (table_insn)) == ADDR_DIFF_VEC)
- {
- rtx table = PATTERN (table_insn);
-
- if (offset >= 0
- && (offset / GET_MODE_SIZE (GET_MODE (table))
- < XVECLEN (table, 1)))
- {
- offset /= GET_MODE_SIZE (GET_MODE (table));
- new = gen_rtx_MINUS (Pmode, XVECEXP (table, 1, offset),
- XEXP (table, 0));
-
- if (GET_MODE (table) != Pmode)
- new = gen_rtx_TRUNCATE (GET_MODE (table), new);
-
- /* Indicate this is a constant. This isn't a
- valid form of CONST, but it will only be used
- to fold the next insns and then discarded, so
- it should be safe.
-
- Note this expression must be explicitly discarded,
- by cse_insn, else it may end up in a REG_EQUAL note
- and "escape" to cause problems elsewhere. */
- return gen_rtx_CONST (GET_MODE (new), new);
- }
- }
- }
-
- return x;
- }
+ return fold_rtx_mem (x, insn);
#ifdef NO_FUNCTION_CSE
case CALL:
/* It's not safe to substitute the operand of a conversion
operator with a constant, as the conversion's identity
- depends upon the mode of it's operand. This optimization
+ depends upon the mode of its operand. This optimization
is handled by the call to simplify_unary_operation. */
if (GET_RTX_CLASS (code) == RTX_UNARY
&& GET_MODE (replacements[j]) != mode_arg0
return 0;
}
\f
-/* Assuming that X is an rtx (e.g., MEM, REG or SUBREG) for a fixed-point
- number, return an rtx (MEM, SUBREG, or CONST_INT) that refers to the
- least-significant part of X.
- MODE specifies how big a part of X to return.
-
- If the requested operation cannot be done, 0 is returned.
-
- This is similar to gen_lowpart_general in emit-rtl.c. */
-
-rtx
-gen_lowpart_if_possible (enum machine_mode mode, rtx x)
-{
- rtx result = gen_lowpart_common (mode, x);
-
- if (result)
- return result;
- else if (MEM_P (x))
- {
- /* This is the only other case we handle. */
- int offset = 0;
- rtx new;
-
- if (WORDS_BIG_ENDIAN)
- offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD)
- - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD));
- if (BYTES_BIG_ENDIAN)
- /* Adjust the address so that the address-after-the-data is
- unchanged. */
- offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode))
- - MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x))));
-
- new = adjust_address_nv (x, mode, offset);
- if (! memory_address_p (mode, XEXP (new, 0)))
- return 0;
-
- return new;
- }
- else
- return 0;
-}
-\f
/* Given INSN, a jump insn, PATH_TAKEN indicates if we are following the "taken"
branch. It will be zero if not.
else if (constant_pool_entries_cost
&& CONSTANT_P (trial)
- /* Reject cases that will abort in decode_rtx_const.
- On the alpha when simplifying a switch, we get
- (const (truncate (minus (label_ref) (label_ref)))). */
+ /* Reject cases that will cause decode_rtx_const to
+ die. On the alpha when simplifying a switch, we
+ get (const (truncate (minus (label_ref)
+ (label_ref)))). */
&& ! (GET_CODE (trial) == CONST
&& GET_CODE (XEXP (trial, 0)) == TRUNCATE)
/* Likewise on IA-64, except without the truncate. */
timevar_push (TV_DELETE_TRIVIALLY_DEAD);
/* First count the number of times each register is used. */
counts = xcalloc (nreg, sizeof (int));
- for (insn = next_real_insn (insns); insn; insn = next_real_insn (insn))
- count_reg_usage (insn, counts, 1);
+ for (insn = insns; insn; insn = NEXT_INSN (insn))
+ if (INSN_P (insn))
+ count_reg_usage (insn, counts, 1);
/* Go from the last insn to the first and delete insns that only set unused
registers or copy a register to itself. As we delete an insn, remove
The first jump optimization pass may leave a real insn as the last
insn in the function. We must not skip that insn or we may end
up deleting code that is not really dead. */
- insn = get_last_insn ();
- if (! INSN_P (insn))
- insn = prev_real_insn (insn);
-
- for (; insn; insn = prev)
+ for (insn = get_last_insn (); insn; insn = prev)
{
int live_insn = 0;
- prev = prev_real_insn (insn);
+ prev = PREV_INSN (insn);
+ if (!INSN_P (insn))
+ continue;
/* Don't delete any insns that are part of a libcall block unless
we can delete the whole libcall block.
ndead++;
}
- if (find_reg_note (insn, REG_LIBCALL, NULL_RTX))
+ if (in_libcall && find_reg_note (insn, REG_LIBCALL, NULL_RTX))
{
in_libcall = 0;
dead_libcall = 0;
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