/* Rtl-level induction variable analysis.
Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
-
+
This file is part of GCC.
-
+
GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
later version.
-
+
GCC is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
-
+
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
iv_analysis_done () to clean up the memory.
The available functions are:
-
+
iv_analyze (insn, reg, iv): Stores the description of the induction variable
corresponding to the use of register REG in INSN to IV. Returns true if
REG is an induction variable in INSN. false otherwise.
#include "expr.h"
#include "intl.h"
#include "output.h"
+#include "diagnostic-core.h"
#include "toplev.h"
#include "df.h"
#include "hashtab.h"
fprintf (file, " (first special)");
}
-/* Truncate EXPR (which has mode EXPR_MODE) to MODE. */
+/* Generates a subreg to get the least significant part of EXPR (in mode
+ INNER_MODE) to OUTER_MODE. */
-static rtx
-truncate_value (enum machine_mode mode, rtx expr, enum machine_mode expr_mode)
+rtx
+lowpart_subreg (enum machine_mode outer_mode, rtx expr,
+ enum machine_mode inner_mode)
{
- return simplify_gen_unary (TRUNCATE, mode, expr, expr_mode);
+ return simplify_gen_subreg (outer_mode, expr, inner_mode,
+ subreg_lowpart_offset (outer_mode, inner_mode));
}
-static void
+static void
check_iv_ref_table_size (void)
{
if (iv_ref_table_size < DF_DEFS_TABLE_SIZE())
{
unsigned int new_size = DF_DEFS_TABLE_SIZE () + (DF_DEFS_TABLE_SIZE () / 4);
iv_ref_table = XRESIZEVEC (struct rtx_iv *, iv_ref_table, new_size);
- memset (&iv_ref_table[iv_ref_table_size], 0,
+ memset (&iv_ref_table[iv_ref_table_size], 0,
(new_size - iv_ref_table_size) * sizeof (struct rtx_iv *));
iv_ref_table_size = new_size;
}
df_remove_problem (df_chain);
df_process_deferred_rescans ();
df_chain_add_problem (DF_UD_CHAIN);
+ df_note_add_problem ();
df_set_blocks (blocks);
df_analyze ();
if (dump_file)
for (adef = DF_REG_DEF_CHAIN (regno); adef; adef = DF_REF_NEXT_REG (adef))
{
if (!bitmap_bit_p (df->blocks_to_analyze, DF_REF_BBNO (adef))
- || !bitmap_bit_p (bb_info->out, DF_REF_ID (adef)))
+ || !bitmap_bit_p (&bb_info->out, DF_REF_ID (adef)))
continue;
/* More than one reaching definition. */
basic_block def_bb, use_bb;
rtx def_insn;
bool dom_p;
-
+
*def = NULL;
if (!simple_reg_p (reg))
return GRD_INVALID;
&& !iv->first_special)
{
rtx val = get_iv_value (iv, const0_rtx);
- val = truncate_value (mode, val, iv->extend_mode);
+ val = lowpart_subreg (mode, val, iv->extend_mode);
iv->base = val;
iv->extend = UNKNOWN;
print_rtl (dump_file, def);
fprintf (dump_file, " for bivness.\n");
}
-
+
if (!REG_P (def))
{
if (!CONSTANT_P (def))
return iv->base != NULL_RTX;
}
-/* Analyzes expression RHS used at INSN and stores the result to *IV.
+/* Analyzes expression RHS used at INSN and stores the result to *IV.
The mode of the induction variable is MODE. */
bool
{
if (!iv_analyze_op (insn, rhs, iv))
return false;
-
+
if (iv->mode == VOIDmode)
{
iv->mode = mode;
fprintf (dump_file, " in insn ");
print_rtl_single (dump_file, insn);
}
-
+
check_iv_ref_table_size ();
if (DF_REF_IV (def))
{
print_rtl_single (dump_file, insn);
}
- if (CONSTANT_P (op))
+ if (function_invariant_p (op))
res = GRD_INVARIANT;
else if (GET_CODE (op) == SUBREG)
{
if (iv->extend_mode == iv->mode)
return val;
- val = truncate_value (iv->mode, val, iv->extend_mode);
+ val = lowpart_subreg (iv->mode, val, iv->extend_mode);
if (iv->extend == UNKNOWN)
return val;
{
rtx op0, op1;
- if (CONSTANT_P (rhs)
+ if (function_invariant_p (rhs)
|| (REG_P (rhs) && !HARD_REGISTER_P (rhs)))
return true;
{
case PLUS:
case MINUS:
+ case AND:
op0 = XEXP (rhs, 0);
op1 = XEXP (rhs, 1);
- /* Allow reg + const and reg + reg. */
+ /* Allow reg OP const and reg OP reg. */
if (!(REG_P (op0) && !HARD_REGISTER_P (op0))
- && !CONSTANT_P (op0))
+ && !function_invariant_p (op0))
return false;
if (!(REG_P (op1) && !HARD_REGISTER_P (op1))
- && !CONSTANT_P (op1))
+ && !function_invariant_p (op1))
return false;
return true;
case ASHIFT:
+ case ASHIFTRT:
+ case LSHIFTRT:
+ case MULT:
op0 = XEXP (rhs, 0);
op1 = XEXP (rhs, 1);
- /* Allow reg << const. */
+ /* Allow reg OP const. */
if (!(REG_P (op0) && !HARD_REGISTER_P (op0)))
return false;
- if (!CONSTANT_P (op1))
+ if (!function_invariant_p (op1))
return false;
return true;
}
}
-/* Simplifies *EXPR using assignment in INSN. ALTERED is the set of registers
- altered so far. */
+/* If REG has a single definition, replace it with its known value in EXPR.
+ Callback for for_each_rtx. */
-static void
-simplify_using_assignment (rtx insn, rtx *expr, regset altered)
+static int
+replace_single_def_regs (rtx *reg, void *expr1)
{
- rtx set = single_set (insn);
- rtx lhs = NULL_RTX, rhs;
- bool ret = false;
+ unsigned regno;
+ df_ref adef;
+ rtx set, src;
+ rtx *expr = (rtx *)expr1;
- if (set)
- {
- lhs = SET_DEST (set);
- if (!REG_P (lhs)
- || altered_reg_used (&lhs, altered))
- ret = true;
- }
- else
- ret = true;
+ if (!REG_P (*reg))
+ return 0;
- note_stores (PATTERN (insn), mark_altered, altered);
- if (CALL_P (insn))
+ regno = REGNO (*reg);
+ for (;;)
{
- int i;
+ rtx note;
+ adef = DF_REG_DEF_CHAIN (regno);
+ if (adef == NULL || DF_REF_NEXT_REG (adef) != NULL
+ || DF_REF_IS_ARTIFICIAL (adef))
+ return -1;
- /* Kill all call clobbered registers. */
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
- SET_REGNO_REG_SET (altered, i);
+ set = single_set (DF_REF_INSN (adef));
+ if (set == NULL || !REG_P (SET_DEST (set))
+ || REGNO (SET_DEST (set)) != regno)
+ return -1;
+
+ note = find_reg_equal_equiv_note (DF_REF_INSN (adef));
+
+ if (note && function_invariant_p (XEXP (note, 0)))
+ {
+ src = XEXP (note, 0);
+ break;
+ }
+ src = SET_SRC (set);
+
+ if (REG_P (src))
+ {
+ regno = REGNO (src);
+ continue;
+ }
+ break;
}
+ if (!function_invariant_p (src))
+ return -1;
- if (ret)
- return;
+ *expr = simplify_replace_rtx (*expr, *reg, src);
+ return 1;
+}
+
+/* A subroutine of simplify_using_initial_values, this function examines INSN
+ to see if it contains a suitable set that we can use to make a replacement.
+ If it is suitable, return true and set DEST and SRC to the lhs and rhs of
+ the set; return false otherwise. */
+
+static bool
+suitable_set_for_replacement (rtx insn, rtx *dest, rtx *src)
+{
+ rtx set = single_set (insn);
+ rtx lhs = NULL_RTX, rhs;
+
+ if (!set)
+ return false;
+
+ lhs = SET_DEST (set);
+ if (!REG_P (lhs))
+ return false;
rhs = find_reg_equal_equiv_note (insn);
if (rhs)
rhs = SET_SRC (set);
if (!simple_rhs_p (rhs))
- return;
+ return false;
- if (for_each_rtx (&rhs, altered_reg_used, altered))
- return;
+ *dest = lhs;
+ *src = rhs;
+ return true;
+}
- *expr = simplify_replace_rtx (*expr, lhs, rhs);
+/* Using the data returned by suitable_set_for_replacement, replace DEST
+ with SRC in *EXPR and return the new expression. Also call
+ replace_single_def_regs if the replacement changed something. */
+static void
+replace_in_expr (rtx *expr, rtx dest, rtx src)
+{
+ rtx old = *expr;
+ *expr = simplify_replace_rtx (*expr, dest, src);
+ if (old == *expr)
+ return;
+ while (for_each_rtx (expr, replace_single_def_regs, expr) != 0)
+ continue;
}
/* Checks whether A implies B. */
/* A != N is equivalent to A - (N + 1) <u -1. */
if (GET_CODE (a) == NE
- && GET_CODE (op1) == CONST_INT
+ && CONST_INT_P (op1)
&& GET_CODE (b) == LTU
&& opb1 == constm1_rtx
&& GET_CODE (opb0) == PLUS
- && GET_CODE (XEXP (opb0, 1)) == CONST_INT
+ && CONST_INT_P (XEXP (opb0, 1))
/* Avoid overflows. */
&& ((unsigned HOST_WIDE_INT) INTVAL (XEXP (opb0, 1))
!= ((unsigned HOST_WIDE_INT)1
/* Likewise, A != N implies A - N > 0. */
if (GET_CODE (a) == NE
- && GET_CODE (op1) == CONST_INT)
+ && CONST_INT_P (op1))
{
if (GET_CODE (b) == GTU
&& GET_CODE (opb0) == PLUS
&& opb1 == const0_rtx
- && GET_CODE (XEXP (opb0, 1)) == CONST_INT
+ && CONST_INT_P (XEXP (opb0, 1))
/* Avoid overflows. */
&& ((unsigned HOST_WIDE_INT) INTVAL (XEXP (opb0, 1))
!= ((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)))
if (GET_CODE (b) == GEU
&& GET_CODE (opb0) == PLUS
&& opb1 == const1_rtx
- && GET_CODE (XEXP (opb0, 1)) == CONST_INT
+ && CONST_INT_P (XEXP (opb0, 1))
/* Avoid overflows. */
&& ((unsigned HOST_WIDE_INT) INTVAL (XEXP (opb0, 1))
!= ((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)))
/* A >s X, where X is positive, implies A <u Y, if Y is negative. */
if ((GET_CODE (a) == GT || GET_CODE (a) == GE)
- && GET_CODE (op1) == CONST_INT
+ && CONST_INT_P (op1)
&& ((GET_CODE (a) == GT && op1 == constm1_rtx)
|| INTVAL (op1) >= 0)
&& GET_CODE (b) == LTU
- && GET_CODE (opb1) == CONST_INT
+ && CONST_INT_P (opb1)
&& rtx_equal_p (op0, opb0))
return INTVAL (opb1) < 0;
mode = GET_MODE (op1);
gcc_assert (mode != VOIDmode);
- if (GET_CODE (op1) == CONST_INT
+ if (CONST_INT_P (op1)
&& GET_MODE_CLASS (mode) != MODE_CC
&& GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
{
{
rtx rev, reve, exp = *expr;
- if (!COMPARISON_P (exp))
- return;
-
/* If some register gets altered later, we do not really speak about its
value at the time of comparison. */
if (altered
&& for_each_rtx (&cond, altered_reg_used, altered))
return;
+ if (GET_CODE (cond) == EQ
+ && REG_P (XEXP (cond, 0)) && CONSTANT_P (XEXP (cond, 1)))
+ {
+ *expr = simplify_replace_rtx (*expr, XEXP (cond, 0), XEXP (cond, 1));
+ return;
+ }
+
+ if (!COMPARISON_P (exp))
+ return;
+
rev = reversed_condition (cond);
reve = reversed_condition (exp);
return;
}
-
if (rev && rtx_equal_p (exp, rev))
{
*expr = const0_rtx;
*expr = const_true_rtx;
return;
}
-
+
if (reve && implies_p (cond, reve))
{
*expr = const0_rtx;
static void
simplify_using_initial_values (struct loop *loop, enum rtx_code op, rtx *expr)
{
- rtx head, tail, insn;
+ bool expression_valid;
+ rtx head, tail, insn, cond_list, last_valid_expr;
rtx neutral, aggr;
- regset altered;
+ regset altered, this_altered;
edge e;
if (!*expr)
default:
gcc_unreachable ();
}
-
+
simplify_using_initial_values (loop, UNKNOWN, &head);
if (head == aggr)
{
*expr = tail;
return;
}
-
+
XEXP (*expr, 0) = head;
XEXP (*expr, 1) = tail;
return;
gcc_assert (op == UNKNOWN);
+ for (;;)
+ if (for_each_rtx (expr, replace_single_def_regs, expr) == 0)
+ break;
+ if (CONSTANT_P (*expr))
+ return;
+
e = loop_preheader_edge (loop);
if (e->src == ENTRY_BLOCK_PTR)
return;
altered = ALLOC_REG_SET (®_obstack);
+ this_altered = ALLOC_REG_SET (®_obstack);
+ expression_valid = true;
+ last_valid_expr = *expr;
+ cond_list = NULL_RTX;
while (1)
{
insn = BB_END (e->src);
if (any_condjump_p (insn))
{
rtx cond = get_condition (BB_END (e->src), NULL, false, true);
-
+
if (cond && (e->flags & EDGE_FALLTHRU))
cond = reversed_condition (cond);
if (cond)
{
+ rtx old = *expr;
simplify_using_condition (cond, expr, altered);
- if (CONSTANT_P (*expr))
+ if (old != *expr)
{
- FREE_REG_SET (altered);
- return;
+ rtx note;
+ if (CONSTANT_P (*expr))
+ goto out;
+ for (note = cond_list; note; note = XEXP (note, 1))
+ {
+ simplify_using_condition (XEXP (note, 0), expr, altered);
+ if (CONSTANT_P (*expr))
+ goto out;
+ }
}
+ cond_list = alloc_EXPR_LIST (0, cond, cond_list);
}
}
FOR_BB_INSNS_REVERSE (e->src, insn)
{
+ rtx src, dest;
+ rtx old = *expr;
+
if (!INSN_P (insn))
continue;
-
- simplify_using_assignment (insn, expr, altered);
- if (CONSTANT_P (*expr))
+
+ CLEAR_REG_SET (this_altered);
+ note_stores (PATTERN (insn), mark_altered, this_altered);
+ if (CALL_P (insn))
{
- FREE_REG_SET (altered);
- return;
+ int i;
+
+ /* Kill all call clobbered registers. */
+ for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
+ if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
+ SET_REGNO_REG_SET (this_altered, i);
}
- if (for_each_rtx (expr, altered_reg_used, altered))
+
+ if (suitable_set_for_replacement (insn, &dest, &src))
{
- FREE_REG_SET (altered);
- return;
+ rtx *pnote, *pnote_next;
+
+ replace_in_expr (expr, dest, src);
+ if (CONSTANT_P (*expr))
+ goto out;
+
+ for (pnote = &cond_list; *pnote; pnote = pnote_next)
+ {
+ rtx note = *pnote;
+ rtx old_cond = XEXP (note, 0);
+
+ pnote_next = &XEXP (note, 1);
+ replace_in_expr (&XEXP (note, 0), dest, src);
+
+ /* We can no longer use a condition that has been simplified
+ to a constant, and simplify_using_condition will abort if
+ we try. */
+ if (CONSTANT_P (XEXP (note, 0)))
+ {
+ *pnote = *pnote_next;
+ pnote_next = pnote;
+ free_EXPR_LIST_node (note);
+ }
+ /* Retry simplifications with this condition if either the
+ expression or the condition changed. */
+ else if (old_cond != XEXP (note, 0) || old != *expr)
+ simplify_using_condition (XEXP (note, 0), expr, altered);
+ }
}
+ else
+ /* If we did not use this insn to make a replacement, any overlap
+ between stores in this insn and our expression will cause the
+ expression to become invalid. */
+ if (for_each_rtx (expr, altered_reg_used, this_altered))
+ goto out;
+
+ if (CONSTANT_P (*expr))
+ goto out;
+
+ IOR_REG_SET (altered, this_altered);
+
+ /* If the expression now contains regs that have been altered, we
+ can't return it to the caller. However, it is still valid for
+ further simplification, so keep searching to see if we can
+ eventually turn it into a constant. */
+ if (for_each_rtx (expr, altered_reg_used, altered))
+ expression_valid = false;
+ if (expression_valid)
+ last_valid_expr = *expr;
}
if (!single_pred_p (e->src)
e = single_pred_edge (e->src);
}
+ out:
+ free_EXPR_LIST_list (&cond_list);
+ if (!CONSTANT_P (*expr))
+ *expr = last_valid_expr;
FREE_REG_SET (altered);
+ FREE_REG_SET (this_altered);
}
/* Transforms invariant IV into MODE. Adds assumptions based on the fact
and iv0 and iv1 are both ivs iterating in SI mode, but calculated
in different modes. This does not seem impossible to handle, but
it hardly ever occurs in practice.
-
+
The only exception is the case when one of operands is invariant.
For example pentium 3 generates comparisons like
(lt (subreg:HI (reg:SI)) 100). Here we assign HImode to 100, but we
return true;
}
-/* Tries to estimate the maximum number of iterations. */
+/* Tries to estimate the maximum number of iterations in LOOP, and store the
+ result in DESC. This function is called from iv_number_of_iterations with
+ a number of fields in DESC already filled in. OLD_NITER is the original
+ expression for the number of iterations, before we tried to simplify it. */
static unsigned HOST_WIDEST_INT
-determine_max_iter (struct loop *loop, struct niter_desc *desc)
+determine_max_iter (struct loop *loop, struct niter_desc *desc, rtx old_niter)
{
rtx niter = desc->niter_expr;
rtx mmin, mmax, cmp;
unsigned HOST_WIDEST_INT nmax, inc;
if (GET_CODE (niter) == AND
- && GET_CODE (XEXP (niter, 0)) == CONST_INT)
+ && CONST_INT_P (XEXP (niter, 0)))
{
nmax = INTVAL (XEXP (niter, 0));
if (!(nmax & (nmax + 1)))
if (GET_CODE (niter) == UDIV)
{
- if (GET_CODE (XEXP (niter, 1)) != CONST_INT)
+ if (!CONST_INT_P (XEXP (niter, 1)))
{
desc->niter_max = nmax;
return nmax;
/* We could use a binary search here, but for now improving the upper
bound by just one eliminates one important corner case. */
- cmp = gen_rtx_fmt_ee (desc->signed_p ? LT : LTU, VOIDmode, niter, mmax);
+ cmp = simplify_gen_relational (desc->signed_p ? LT : LTU, VOIDmode,
+ desc->mode, old_niter, mmax);
simplify_using_initial_values (loop, UNKNOWN, &cmp);
if (cmp == const_true_rtx)
{
goto fail;
if (iv0.extend_mode == VOIDmode)
iv0.mode = iv0.extend_mode = mode;
-
+
op1 = XEXP (condition, 1);
if (!iv_analyze (insn, op1, &iv1))
goto fail;
mode = iv0.mode;
size = GET_MODE_BITSIZE (mode);
get_mode_bounds (mode, (cond == LE || cond == LT), comp_mode, &mmin, &mmax);
- mode_mmin = truncate_value (mode, mmin, comp_mode);
- mode_mmax = truncate_value (mode, mmax, comp_mode);
+ mode_mmin = lowpart_subreg (mode, mmin, comp_mode);
+ mode_mmax = lowpart_subreg (mode, mmax, comp_mode);
- if (GET_CODE (iv0.step) != CONST_INT || GET_CODE (iv1.step) != CONST_INT)
+ if (!CONST_INT_P (iv0.step) || !CONST_INT_P (iv1.step))
goto fail;
/* We can take care of the case of two induction variables chasing each other
difficult due to possibly infinite loops. */
if (iv0.step == const0_rtx)
{
- tmp = truncate_value (mode, iv0.base, comp_mode);
+ tmp = lowpart_subreg (mode, iv0.base, comp_mode);
assumption = simplify_gen_relational (EQ, SImode, mode, tmp,
mode_mmax);
if (assumption == const_true_rtx)
}
else
{
- tmp = truncate_value (mode, iv1.base, comp_mode);
+ tmp = lowpart_subreg (mode, iv1.base, comp_mode);
assumption = simplify_gen_relational (EQ, SImode, mode, tmp,
mode_mmin);
if (assumption == const_true_rtx)
{
if (iv0.step == const0_rtx)
{
- tmp = truncate_value (mode, iv0.base, comp_mode);
+ tmp = lowpart_subreg (mode, iv0.base, comp_mode);
if (rtx_equal_p (tmp, mode_mmin))
{
desc->infinite =
}
else
{
- tmp = truncate_value (mode, iv1.base, comp_mode);
+ tmp = lowpart_subreg (mode, iv1.base, comp_mode);
if (rtx_equal_p (tmp, mode_mmax))
{
desc->infinite =
else
step = iv0.step;
delta = simplify_gen_binary (MINUS, comp_mode, iv1.base, iv0.base);
- delta = truncate_value (mode, delta, comp_mode);
+ delta = lowpart_subreg (mode, delta, comp_mode);
delta = simplify_gen_binary (UMOD, mode, delta, step);
may_xform = const0_rtx;
may_not_xform = const_true_rtx;
- if (GET_CODE (delta) == CONST_INT)
+ if (CONST_INT_P (delta))
{
if (was_sharp && INTVAL (delta) == INTVAL (step) - 1)
{
{
bound = simplify_gen_binary (PLUS, comp_mode, mmin, step);
bound = simplify_gen_binary (MINUS, comp_mode, bound, delta);
- bound = truncate_value (mode, bound, comp_mode);
- tmp = truncate_value (mode, iv0.base, comp_mode);
+ bound = lowpart_subreg (mode, bound, comp_mode);
+ tmp = lowpart_subreg (mode, iv0.base, comp_mode);
may_xform = simplify_gen_relational (cond, SImode, mode,
bound, tmp);
may_not_xform = simplify_gen_relational (reverse_condition (cond),
{
bound = simplify_gen_binary (MINUS, comp_mode, mmax, step);
bound = simplify_gen_binary (PLUS, comp_mode, bound, delta);
- bound = truncate_value (mode, bound, comp_mode);
- tmp = truncate_value (mode, iv1.base, comp_mode);
+ bound = lowpart_subreg (mode, bound, comp_mode);
+ tmp = lowpart_subreg (mode, iv1.base, comp_mode);
may_xform = simplify_gen_relational (cond, SImode, mode,
tmp, bound);
may_not_xform = simplify_gen_relational (reverse_condition (cond),
number of iterations in this step, so record the information
here. */
inc = INTVAL (iv0.step) - INTVAL (iv1.step);
- if (GET_CODE (iv1.base) == CONST_INT)
+ if (CONST_INT_P (iv1.base))
up = INTVAL (iv1.base);
else
up = INTVAL (mode_mmax) - inc;
- down = INTVAL (GET_CODE (iv0.base) == CONST_INT
+ down = INTVAL (CONST_INT_P (iv0.base)
? iv0.base
: mode_mmin);
desc->niter_max = (up - down) / inc + 1;
iv1.base = simplify_gen_binary (PLUS, comp_mode, iv1.base, step);
}
- tmp0 = truncate_value (mode, iv0.base, comp_mode);
- tmp1 = truncate_value (mode, iv1.base, comp_mode);
+ tmp0 = lowpart_subreg (mode, iv0.base, comp_mode);
+ tmp1 = lowpart_subreg (mode, iv1.base, comp_mode);
assumption = simplify_gen_relational (reverse_condition (cond),
SImode, mode, tmp0, tmp1);
if (assumption == const_true_rtx)
iv0.step = simplify_gen_unary (NEG, comp_mode, iv0.step, mode);
iv1.base = simplify_gen_unary (NEG, comp_mode, iv1.base, mode);
}
- iv0.step = truncate_value (mode, iv0.step, comp_mode);
+ iv0.step = lowpart_subreg (mode, iv0.step, comp_mode);
/* Let nsd (s, size of mode) = d. If d does not divide c, the loop
is infinite. Otherwise, the number of iterations is
}
bound = GEN_INT (((unsigned HOST_WIDEST_INT) 1 << (size - 1 ) << 1) - 1);
- tmp1 = truncate_value (mode, iv1.base, comp_mode);
+ tmp1 = lowpart_subreg (mode, iv1.base, comp_mode);
tmp = simplify_gen_binary (UMOD, mode, tmp1, GEN_INT (d));
assumption = simplify_gen_relational (NE, SImode, mode, tmp, const0_rtx);
desc->infinite = alloc_EXPR_LIST (0, assumption, desc->infinite);
but it was already taken into account during LE -> NE transform). */
{
step = iv0.step;
- tmp0 = truncate_value (mode, iv0.base, comp_mode);
- tmp1 = truncate_value (mode, iv1.base, comp_mode);
+ tmp0 = lowpart_subreg (mode, iv0.base, comp_mode);
+ tmp1 = lowpart_subreg (mode, iv1.base, comp_mode);
bound = simplify_gen_binary (MINUS, mode, mode_mmax,
- truncate_value (mode, step, comp_mode));
+ lowpart_subreg (mode, step,
+ comp_mode));
if (step_is_pow2)
{
rtx t0, t1;
}
tmp = simplify_gen_binary (PLUS, comp_mode, iv1.base, iv0.step);
- tmp = truncate_value (mode, tmp, comp_mode);
+ tmp = lowpart_subreg (mode, tmp, comp_mode);
assumption = simplify_gen_relational (reverse_condition (cond),
SImode, mode, tmp0, tmp);
We must know that a - s does not overflow and a - s <= b and then
we can again compute number of iterations as (b - (a - s)) / s. */
step = simplify_gen_unary (NEG, mode, iv1.step, mode);
- tmp0 = truncate_value (mode, iv0.base, comp_mode);
- tmp1 = truncate_value (mode, iv1.base, comp_mode);
+ tmp0 = lowpart_subreg (mode, iv0.base, comp_mode);
+ tmp1 = lowpart_subreg (mode, iv1.base, comp_mode);
bound = simplify_gen_binary (PLUS, mode, mode_mmin,
- truncate_value (mode, step, comp_mode));
+ lowpart_subreg (mode, step, comp_mode));
if (step_is_pow2)
{
rtx t0, t1;
}
tmp = simplify_gen_binary (PLUS, comp_mode, iv0.base, iv1.step);
- tmp = truncate_value (mode, tmp, comp_mode);
+ tmp = lowpart_subreg (mode, tmp, comp_mode);
assumption = simplify_gen_relational (reverse_condition (cond),
SImode, mode,
tmp, tmp1);
&& XEXP (desc->noloop_assumptions, 0) == const_true_rtx)
goto zero_iter;
- if (GET_CODE (desc->niter_expr) == CONST_INT)
+ if (CONST_INT_P (desc->niter_expr))
{
unsigned HOST_WIDEST_INT val = INTVAL (desc->niter_expr);
else
{
if (!desc->niter_max)
- desc->niter_max = determine_max_iter (loop, desc);
+ desc->niter_max = determine_max_iter (loop, desc, old_niter);
/* simplify_using_initial_values does a copy propagation on the registers
in the expression for the number of iterations. This prolongs life
{
if (flow_bb_inside_loop_p (loop, e->dest))
continue;
-
+
check_simple_exit (loop, e, &act);
if (!act.simple_p)
continue;
if (act.infinite && !desc->infinite)
continue;
}
-
+
*desc = act;
}
}
if (desc)
return desc;
- desc = XNEW (struct niter_desc);
+ /* At least desc->infinite is not always initialized by
+ find_simple_loop_exit. */
+ desc = XCNEW (struct niter_desc);
iv_analysis_loop_init (loop);
find_simple_exit (loop, desc);
loop->aux = desc;
if (desc->simple_p && (desc->assumptions || desc->infinite))
{
- const char *wording;
+ const char *wording;
- /* Assume that no overflow happens and that the loop is finite.
+ /* Assume that no overflow happens and that the loop is finite.
We already warned at the tree level if we ran optimizations there. */
if (!flag_tree_loop_optimize && warn_unsafe_loop_optimizations)
{
if (desc->infinite)
{
- wording =
+ wording =
flag_unsafe_loop_optimizations
? N_("assuming that the loop is not infinite")
: N_("cannot optimize possibly infinite loops");
}
if (desc->assumptions)
{
- wording =
+ wording =
flag_unsafe_loop_optimizations
? N_("assuming that the loop counter does not overflow")
: N_("cannot optimize loop, the loop counter may overflow");