/* Optimization of PHI nodes by converting them into straightline code.
|
/* Optimization of PHI nodes by converting them into straightline code.
|
Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation,
|
Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation,
|
Inc.
|
Inc.
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|
|
This file is part of GCC.
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This file is part of GCC.
|
|
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GCC is free software; you can redistribute it and/or modify it
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GCC is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 3, or (at your option) any
|
Free Software Foundation; either version 3, or (at your option) any
|
later version.
|
later version.
|
|
|
GCC is distributed in the hope that it will be useful, but WITHOUT
|
GCC is distributed in the hope that it will be useful, but WITHOUT
|
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
for more details.
|
for more details.
|
|
|
You should have received a copy of the GNU General Public License
|
You should have received a copy of the GNU General Public License
|
along with GCC; see the file COPYING3. If not see
|
along with GCC; see the file COPYING3. If not see
|
<http://www.gnu.org/licenses/>. */
|
<http://www.gnu.org/licenses/>. */
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|
|
#include "config.h"
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#include "config.h"
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#include "system.h"
|
#include "system.h"
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#include "coretypes.h"
|
#include "coretypes.h"
|
#include "tm.h"
|
#include "tm.h"
|
#include "ggc.h"
|
#include "ggc.h"
|
#include "tree.h"
|
#include "tree.h"
|
#include "rtl.h"
|
#include "rtl.h"
|
#include "flags.h"
|
#include "flags.h"
|
#include "tm_p.h"
|
#include "tm_p.h"
|
#include "basic-block.h"
|
#include "basic-block.h"
|
#include "timevar.h"
|
#include "timevar.h"
|
#include "diagnostic.h"
|
#include "diagnostic.h"
|
#include "tree-flow.h"
|
#include "tree-flow.h"
|
#include "tree-pass.h"
|
#include "tree-pass.h"
|
#include "tree-dump.h"
|
#include "tree-dump.h"
|
#include "langhooks.h"
|
#include "langhooks.h"
|
#include "pointer-set.h"
|
#include "pointer-set.h"
|
#include "domwalk.h"
|
#include "domwalk.h"
|
|
|
static unsigned int tree_ssa_phiopt (void);
|
static unsigned int tree_ssa_phiopt (void);
|
static unsigned int tree_ssa_phiopt_worker (bool);
|
static unsigned int tree_ssa_phiopt_worker (bool);
|
static bool conditional_replacement (basic_block, basic_block,
|
static bool conditional_replacement (basic_block, basic_block,
|
edge, edge, gimple, tree, tree);
|
edge, edge, gimple, tree, tree);
|
static bool value_replacement (basic_block, basic_block,
|
static bool value_replacement (basic_block, basic_block,
|
edge, edge, gimple, tree, tree);
|
edge, edge, gimple, tree, tree);
|
static bool minmax_replacement (basic_block, basic_block,
|
static bool minmax_replacement (basic_block, basic_block,
|
edge, edge, gimple, tree, tree);
|
edge, edge, gimple, tree, tree);
|
static bool abs_replacement (basic_block, basic_block,
|
static bool abs_replacement (basic_block, basic_block,
|
edge, edge, gimple, tree, tree);
|
edge, edge, gimple, tree, tree);
|
static bool cond_store_replacement (basic_block, basic_block, edge, edge,
|
static bool cond_store_replacement (basic_block, basic_block, edge, edge,
|
struct pointer_set_t *);
|
struct pointer_set_t *);
|
static struct pointer_set_t * get_non_trapping (void);
|
static struct pointer_set_t * get_non_trapping (void);
|
static void replace_phi_edge_with_variable (basic_block, edge, gimple, tree);
|
static void replace_phi_edge_with_variable (basic_block, edge, gimple, tree);
|
|
|
/* This pass tries to replaces an if-then-else block with an
|
/* This pass tries to replaces an if-then-else block with an
|
assignment. We have four kinds of transformations. Some of these
|
assignment. We have four kinds of transformations. Some of these
|
transformations are also performed by the ifcvt RTL optimizer.
|
transformations are also performed by the ifcvt RTL optimizer.
|
|
|
Conditional Replacement
|
Conditional Replacement
|
-----------------------
|
-----------------------
|
|
|
This transformation, implemented in conditional_replacement,
|
This transformation, implemented in conditional_replacement,
|
replaces
|
replaces
|
|
|
bb0:
|
bb0:
|
if (cond) goto bb2; else goto bb1;
|
if (cond) goto bb2; else goto bb1;
|
bb1:
|
bb1:
|
bb2:
|
bb2:
|
x = PHI <0 (bb1), 1 (bb0), ...>;
|
x = PHI <0 (bb1), 1 (bb0), ...>;
|
|
|
with
|
with
|
|
|
bb0:
|
bb0:
|
x' = cond;
|
x' = cond;
|
goto bb2;
|
goto bb2;
|
bb2:
|
bb2:
|
x = PHI <x' (bb0), ...>;
|
x = PHI <x' (bb0), ...>;
|
|
|
We remove bb1 as it becomes unreachable. This occurs often due to
|
We remove bb1 as it becomes unreachable. This occurs often due to
|
gimplification of conditionals.
|
gimplification of conditionals.
|
|
|
Value Replacement
|
Value Replacement
|
-----------------
|
-----------------
|
|
|
This transformation, implemented in value_replacement, replaces
|
This transformation, implemented in value_replacement, replaces
|
|
|
bb0:
|
bb0:
|
if (a != b) goto bb2; else goto bb1;
|
if (a != b) goto bb2; else goto bb1;
|
bb1:
|
bb1:
|
bb2:
|
bb2:
|
x = PHI <a (bb1), b (bb0), ...>;
|
x = PHI <a (bb1), b (bb0), ...>;
|
|
|
with
|
with
|
|
|
bb0:
|
bb0:
|
bb2:
|
bb2:
|
x = PHI <b (bb0), ...>;
|
x = PHI <b (bb0), ...>;
|
|
|
This opportunity can sometimes occur as a result of other
|
This opportunity can sometimes occur as a result of other
|
optimizations.
|
optimizations.
|
|
|
ABS Replacement
|
ABS Replacement
|
---------------
|
---------------
|
|
|
This transformation, implemented in abs_replacement, replaces
|
This transformation, implemented in abs_replacement, replaces
|
|
|
bb0:
|
bb0:
|
if (a >= 0) goto bb2; else goto bb1;
|
if (a >= 0) goto bb2; else goto bb1;
|
bb1:
|
bb1:
|
x = -a;
|
x = -a;
|
bb2:
|
bb2:
|
x = PHI <x (bb1), a (bb0), ...>;
|
x = PHI <x (bb1), a (bb0), ...>;
|
|
|
with
|
with
|
|
|
bb0:
|
bb0:
|
x' = ABS_EXPR< a >;
|
x' = ABS_EXPR< a >;
|
bb2:
|
bb2:
|
x = PHI <x' (bb0), ...>;
|
x = PHI <x' (bb0), ...>;
|
|
|
MIN/MAX Replacement
|
MIN/MAX Replacement
|
-------------------
|
-------------------
|
|
|
This transformation, minmax_replacement replaces
|
This transformation, minmax_replacement replaces
|
|
|
bb0:
|
bb0:
|
if (a <= b) goto bb2; else goto bb1;
|
if (a <= b) goto bb2; else goto bb1;
|
bb1:
|
bb1:
|
bb2:
|
bb2:
|
x = PHI <b (bb1), a (bb0), ...>;
|
x = PHI <b (bb1), a (bb0), ...>;
|
|
|
with
|
with
|
|
|
bb0:
|
bb0:
|
x' = MIN_EXPR (a, b)
|
x' = MIN_EXPR (a, b)
|
bb2:
|
bb2:
|
x = PHI <x' (bb0), ...>;
|
x = PHI <x' (bb0), ...>;
|
|
|
A similar transformation is done for MAX_EXPR. */
|
A similar transformation is done for MAX_EXPR. */
|
|
|
static unsigned int
|
static unsigned int
|
tree_ssa_phiopt (void)
|
tree_ssa_phiopt (void)
|
{
|
{
|
return tree_ssa_phiopt_worker (false);
|
return tree_ssa_phiopt_worker (false);
|
}
|
}
|
|
|
/* This pass tries to transform conditional stores into unconditional
|
/* This pass tries to transform conditional stores into unconditional
|
ones, enabling further simplifications with the simpler then and else
|
ones, enabling further simplifications with the simpler then and else
|
blocks. In particular it replaces this:
|
blocks. In particular it replaces this:
|
|
|
bb0:
|
bb0:
|
if (cond) goto bb2; else goto bb1;
|
if (cond) goto bb2; else goto bb1;
|
bb1:
|
bb1:
|
*p = RHS
|
*p = RHS
|
bb2:
|
bb2:
|
|
|
with
|
with
|
|
|
bb0:
|
bb0:
|
if (cond) goto bb1; else goto bb2;
|
if (cond) goto bb1; else goto bb2;
|
bb1:
|
bb1:
|
condtmp' = *p;
|
condtmp' = *p;
|
bb2:
|
bb2:
|
condtmp = PHI <RHS, condtmp'>
|
condtmp = PHI <RHS, condtmp'>
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*p = condtmp
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*p = condtmp
|
|
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This transformation can only be done under several constraints,
|
This transformation can only be done under several constraints,
|
documented below. */
|
documented below. */
|
|
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static unsigned int
|
static unsigned int
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tree_ssa_cs_elim (void)
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tree_ssa_cs_elim (void)
|
{
|
{
|
return tree_ssa_phiopt_worker (true);
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return tree_ssa_phiopt_worker (true);
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}
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}
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|
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/* For conditional store replacement we need a temporary to
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/* For conditional store replacement we need a temporary to
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put the old contents of the memory in. */
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put the old contents of the memory in. */
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static tree condstoretemp;
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static tree condstoretemp;
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|
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/* The core routine of conditional store replacement and normal
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/* The core routine of conditional store replacement and normal
|
phi optimizations. Both share much of the infrastructure in how
|
phi optimizations. Both share much of the infrastructure in how
|
to match applicable basic block patterns. DO_STORE_ELIM is true
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to match applicable basic block patterns. DO_STORE_ELIM is true
|
when we want to do conditional store replacement, false otherwise. */
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when we want to do conditional store replacement, false otherwise. */
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static unsigned int
|
static unsigned int
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tree_ssa_phiopt_worker (bool do_store_elim)
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tree_ssa_phiopt_worker (bool do_store_elim)
|
{
|
{
|
basic_block bb;
|
basic_block bb;
|
basic_block *bb_order;
|
basic_block *bb_order;
|
unsigned n, i;
|
unsigned n, i;
|
bool cfgchanged = false;
|
bool cfgchanged = false;
|
struct pointer_set_t *nontrap = 0;
|
struct pointer_set_t *nontrap = 0;
|
|
|
if (do_store_elim)
|
if (do_store_elim)
|
{
|
{
|
condstoretemp = NULL_TREE;
|
condstoretemp = NULL_TREE;
|
/* Calculate the set of non-trapping memory accesses. */
|
/* Calculate the set of non-trapping memory accesses. */
|
nontrap = get_non_trapping ();
|
nontrap = get_non_trapping ();
|
}
|
}
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|
|
/* Search every basic block for COND_EXPR we may be able to optimize.
|
/* Search every basic block for COND_EXPR we may be able to optimize.
|
|
|
We walk the blocks in order that guarantees that a block with
|
We walk the blocks in order that guarantees that a block with
|
a single predecessor is processed before the predecessor.
|
a single predecessor is processed before the predecessor.
|
This ensures that we collapse inner ifs before visiting the
|
This ensures that we collapse inner ifs before visiting the
|
outer ones, and also that we do not try to visit a removed
|
outer ones, and also that we do not try to visit a removed
|
block. */
|
block. */
|
bb_order = blocks_in_phiopt_order ();
|
bb_order = blocks_in_phiopt_order ();
|
n = n_basic_blocks - NUM_FIXED_BLOCKS;
|
n = n_basic_blocks - NUM_FIXED_BLOCKS;
|
|
|
for (i = 0; i < n; i++)
|
for (i = 0; i < n; i++)
|
{
|
{
|
gimple cond_stmt, phi;
|
gimple cond_stmt, phi;
|
basic_block bb1, bb2;
|
basic_block bb1, bb2;
|
edge e1, e2;
|
edge e1, e2;
|
tree arg0, arg1;
|
tree arg0, arg1;
|
|
|
bb = bb_order[i];
|
bb = bb_order[i];
|
|
|
cond_stmt = last_stmt (bb);
|
cond_stmt = last_stmt (bb);
|
/* Check to see if the last statement is a GIMPLE_COND. */
|
/* Check to see if the last statement is a GIMPLE_COND. */
|
if (!cond_stmt
|
if (!cond_stmt
|
|| gimple_code (cond_stmt) != GIMPLE_COND)
|
|| gimple_code (cond_stmt) != GIMPLE_COND)
|
continue;
|
continue;
|
|
|
e1 = EDGE_SUCC (bb, 0);
|
e1 = EDGE_SUCC (bb, 0);
|
bb1 = e1->dest;
|
bb1 = e1->dest;
|
e2 = EDGE_SUCC (bb, 1);
|
e2 = EDGE_SUCC (bb, 1);
|
bb2 = e2->dest;
|
bb2 = e2->dest;
|
|
|
/* We cannot do the optimization on abnormal edges. */
|
/* We cannot do the optimization on abnormal edges. */
|
if ((e1->flags & EDGE_ABNORMAL) != 0
|
if ((e1->flags & EDGE_ABNORMAL) != 0
|
|| (e2->flags & EDGE_ABNORMAL) != 0)
|
|| (e2->flags & EDGE_ABNORMAL) != 0)
|
continue;
|
continue;
|
|
|
/* If either bb1's succ or bb2 or bb2's succ is non NULL. */
|
/* If either bb1's succ or bb2 or bb2's succ is non NULL. */
|
if (EDGE_COUNT (bb1->succs) == 0
|
if (EDGE_COUNT (bb1->succs) == 0
|
|| bb2 == NULL
|
|| bb2 == NULL
|
|| EDGE_COUNT (bb2->succs) == 0)
|
|| EDGE_COUNT (bb2->succs) == 0)
|
continue;
|
continue;
|
|
|
/* Find the bb which is the fall through to the other. */
|
/* Find the bb which is the fall through to the other. */
|
if (EDGE_SUCC (bb1, 0)->dest == bb2)
|
if (EDGE_SUCC (bb1, 0)->dest == bb2)
|
;
|
;
|
else if (EDGE_SUCC (bb2, 0)->dest == bb1)
|
else if (EDGE_SUCC (bb2, 0)->dest == bb1)
|
{
|
{
|
basic_block bb_tmp = bb1;
|
basic_block bb_tmp = bb1;
|
edge e_tmp = e1;
|
edge e_tmp = e1;
|
bb1 = bb2;
|
bb1 = bb2;
|
bb2 = bb_tmp;
|
bb2 = bb_tmp;
|
e1 = e2;
|
e1 = e2;
|
e2 = e_tmp;
|
e2 = e_tmp;
|
}
|
}
|
else
|
else
|
continue;
|
continue;
|
|
|
e1 = EDGE_SUCC (bb1, 0);
|
e1 = EDGE_SUCC (bb1, 0);
|
|
|
/* Make sure that bb1 is just a fall through. */
|
/* Make sure that bb1 is just a fall through. */
|
if (!single_succ_p (bb1)
|
if (!single_succ_p (bb1)
|
|| (e1->flags & EDGE_FALLTHRU) == 0)
|
|| (e1->flags & EDGE_FALLTHRU) == 0)
|
continue;
|
continue;
|
|
|
/* Also make sure that bb1 only have one predecessor and that it
|
/* Also make sure that bb1 only have one predecessor and that it
|
is bb. */
|
is bb. */
|
if (!single_pred_p (bb1)
|
if (!single_pred_p (bb1)
|
|| single_pred (bb1) != bb)
|
|| single_pred (bb1) != bb)
|
continue;
|
continue;
|
|
|
if (do_store_elim)
|
if (do_store_elim)
|
{
|
{
|
/* bb1 is the middle block, bb2 the join block, bb the split block,
|
/* bb1 is the middle block, bb2 the join block, bb the split block,
|
e1 the fallthrough edge from bb1 to bb2. We can't do the
|
e1 the fallthrough edge from bb1 to bb2. We can't do the
|
optimization if the join block has more than two predecessors. */
|
optimization if the join block has more than two predecessors. */
|
if (EDGE_COUNT (bb2->preds) > 2)
|
if (EDGE_COUNT (bb2->preds) > 2)
|
continue;
|
continue;
|
if (cond_store_replacement (bb1, bb2, e1, e2, nontrap))
|
if (cond_store_replacement (bb1, bb2, e1, e2, nontrap))
|
cfgchanged = true;
|
cfgchanged = true;
|
}
|
}
|
else
|
else
|
{
|
{
|
gimple_seq phis = phi_nodes (bb2);
|
gimple_seq phis = phi_nodes (bb2);
|
|
|
/* Check to make sure that there is only one PHI node.
|
/* Check to make sure that there is only one PHI node.
|
TODO: we could do it with more than one iff the other PHI nodes
|
TODO: we could do it with more than one iff the other PHI nodes
|
have the same elements for these two edges. */
|
have the same elements for these two edges. */
|
if (! gimple_seq_singleton_p (phis))
|
if (! gimple_seq_singleton_p (phis))
|
continue;
|
continue;
|
|
|
phi = gsi_stmt (gsi_start (phis));
|
phi = gsi_stmt (gsi_start (phis));
|
arg0 = gimple_phi_arg_def (phi, e1->dest_idx);
|
arg0 = gimple_phi_arg_def (phi, e1->dest_idx);
|
arg1 = gimple_phi_arg_def (phi, e2->dest_idx);
|
arg1 = gimple_phi_arg_def (phi, e2->dest_idx);
|
|
|
/* Something is wrong if we cannot find the arguments in the PHI
|
/* Something is wrong if we cannot find the arguments in the PHI
|
node. */
|
node. */
|
gcc_assert (arg0 != NULL && arg1 != NULL);
|
gcc_assert (arg0 != NULL && arg1 != NULL);
|
|
|
/* Do the replacement of conditional if it can be done. */
|
/* Do the replacement of conditional if it can be done. */
|
if (conditional_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
|
if (conditional_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
|
cfgchanged = true;
|
cfgchanged = true;
|
else if (value_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
|
else if (value_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
|
cfgchanged = true;
|
cfgchanged = true;
|
else if (abs_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
|
else if (abs_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
|
cfgchanged = true;
|
cfgchanged = true;
|
else if (minmax_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
|
else if (minmax_replacement (bb, bb1, e1, e2, phi, arg0, arg1))
|
cfgchanged = true;
|
cfgchanged = true;
|
}
|
}
|
}
|
}
|
|
|
free (bb_order);
|
free (bb_order);
|
|
|
if (do_store_elim)
|
if (do_store_elim)
|
pointer_set_destroy (nontrap);
|
pointer_set_destroy (nontrap);
|
/* If the CFG has changed, we should cleanup the CFG. */
|
/* If the CFG has changed, we should cleanup the CFG. */
|
if (cfgchanged && do_store_elim)
|
if (cfgchanged && do_store_elim)
|
{
|
{
|
/* In cond-store replacement we have added some loads on edges
|
/* In cond-store replacement we have added some loads on edges
|
and new VOPS (as we moved the store, and created a load). */
|
and new VOPS (as we moved the store, and created a load). */
|
gsi_commit_edge_inserts ();
|
gsi_commit_edge_inserts ();
|
return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals;
|
return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals;
|
}
|
}
|
else if (cfgchanged)
|
else if (cfgchanged)
|
return TODO_cleanup_cfg;
|
return TODO_cleanup_cfg;
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* Returns the list of basic blocks in the function in an order that guarantees
|
/* Returns the list of basic blocks in the function in an order that guarantees
|
that if a block X has just a single predecessor Y, then Y is after X in the
|
that if a block X has just a single predecessor Y, then Y is after X in the
|
ordering. */
|
ordering. */
|
|
|
basic_block *
|
basic_block *
|
blocks_in_phiopt_order (void)
|
blocks_in_phiopt_order (void)
|
{
|
{
|
basic_block x, y;
|
basic_block x, y;
|
basic_block *order = XNEWVEC (basic_block, n_basic_blocks);
|
basic_block *order = XNEWVEC (basic_block, n_basic_blocks);
|
unsigned n = n_basic_blocks - NUM_FIXED_BLOCKS;
|
unsigned n = n_basic_blocks - NUM_FIXED_BLOCKS;
|
unsigned np, i;
|
unsigned np, i;
|
sbitmap visited = sbitmap_alloc (last_basic_block);
|
sbitmap visited = sbitmap_alloc (last_basic_block);
|
|
|
#define MARK_VISITED(BB) (SET_BIT (visited, (BB)->index))
|
#define MARK_VISITED(BB) (SET_BIT (visited, (BB)->index))
|
#define VISITED_P(BB) (TEST_BIT (visited, (BB)->index))
|
#define VISITED_P(BB) (TEST_BIT (visited, (BB)->index))
|
|
|
sbitmap_zero (visited);
|
sbitmap_zero (visited);
|
|
|
MARK_VISITED (ENTRY_BLOCK_PTR);
|
MARK_VISITED (ENTRY_BLOCK_PTR);
|
FOR_EACH_BB (x)
|
FOR_EACH_BB (x)
|
{
|
{
|
if (VISITED_P (x))
|
if (VISITED_P (x))
|
continue;
|
continue;
|
|
|
/* Walk the predecessors of x as long as they have precisely one
|
/* Walk the predecessors of x as long as they have precisely one
|
predecessor and add them to the list, so that they get stored
|
predecessor and add them to the list, so that they get stored
|
after x. */
|
after x. */
|
for (y = x, np = 1;
|
for (y = x, np = 1;
|
single_pred_p (y) && !VISITED_P (single_pred (y));
|
single_pred_p (y) && !VISITED_P (single_pred (y));
|
y = single_pred (y))
|
y = single_pred (y))
|
np++;
|
np++;
|
for (y = x, i = n - np;
|
for (y = x, i = n - np;
|
single_pred_p (y) && !VISITED_P (single_pred (y));
|
single_pred_p (y) && !VISITED_P (single_pred (y));
|
y = single_pred (y), i++)
|
y = single_pred (y), i++)
|
{
|
{
|
order[i] = y;
|
order[i] = y;
|
MARK_VISITED (y);
|
MARK_VISITED (y);
|
}
|
}
|
order[i] = y;
|
order[i] = y;
|
MARK_VISITED (y);
|
MARK_VISITED (y);
|
|
|
gcc_assert (i == n - 1);
|
gcc_assert (i == n - 1);
|
n -= np;
|
n -= np;
|
}
|
}
|
|
|
sbitmap_free (visited);
|
sbitmap_free (visited);
|
gcc_assert (n == 0);
|
gcc_assert (n == 0);
|
return order;
|
return order;
|
|
|
#undef MARK_VISITED
|
#undef MARK_VISITED
|
#undef VISITED_P
|
#undef VISITED_P
|
}
|
}
|
|
|
|
|
/* Return TRUE if block BB has no executable statements, otherwise return
|
/* Return TRUE if block BB has no executable statements, otherwise return
|
FALSE. */
|
FALSE. */
|
|
|
bool
|
bool
|
empty_block_p (basic_block bb)
|
empty_block_p (basic_block bb)
|
{
|
{
|
/* BB must have no executable statements. */
|
/* BB must have no executable statements. */
|
gimple_stmt_iterator gsi = gsi_after_labels (bb);
|
gimple_stmt_iterator gsi = gsi_after_labels (bb);
|
if (gsi_end_p (gsi))
|
if (gsi_end_p (gsi))
|
return true;
|
return true;
|
if (is_gimple_debug (gsi_stmt (gsi)))
|
if (is_gimple_debug (gsi_stmt (gsi)))
|
gsi_next_nondebug (&gsi);
|
gsi_next_nondebug (&gsi);
|
return gsi_end_p (gsi);
|
return gsi_end_p (gsi);
|
}
|
}
|
|
|
/* Replace PHI node element whose edge is E in block BB with variable NEW.
|
/* Replace PHI node element whose edge is E in block BB with variable NEW.
|
Remove the edge from COND_BLOCK which does not lead to BB (COND_BLOCK
|
Remove the edge from COND_BLOCK which does not lead to BB (COND_BLOCK
|
is known to have two edges, one of which must reach BB). */
|
is known to have two edges, one of which must reach BB). */
|
|
|
static void
|
static void
|
replace_phi_edge_with_variable (basic_block cond_block,
|
replace_phi_edge_with_variable (basic_block cond_block,
|
edge e, gimple phi, tree new_tree)
|
edge e, gimple phi, tree new_tree)
|
{
|
{
|
basic_block bb = gimple_bb (phi);
|
basic_block bb = gimple_bb (phi);
|
basic_block block_to_remove;
|
basic_block block_to_remove;
|
gimple_stmt_iterator gsi;
|
gimple_stmt_iterator gsi;
|
|
|
/* Change the PHI argument to new. */
|
/* Change the PHI argument to new. */
|
SET_USE (PHI_ARG_DEF_PTR (phi, e->dest_idx), new_tree);
|
SET_USE (PHI_ARG_DEF_PTR (phi, e->dest_idx), new_tree);
|
|
|
/* Remove the empty basic block. */
|
/* Remove the empty basic block. */
|
if (EDGE_SUCC (cond_block, 0)->dest == bb)
|
if (EDGE_SUCC (cond_block, 0)->dest == bb)
|
{
|
{
|
EDGE_SUCC (cond_block, 0)->flags |= EDGE_FALLTHRU;
|
EDGE_SUCC (cond_block, 0)->flags |= EDGE_FALLTHRU;
|
EDGE_SUCC (cond_block, 0)->flags &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE);
|
EDGE_SUCC (cond_block, 0)->flags &= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE);
|
EDGE_SUCC (cond_block, 0)->probability = REG_BR_PROB_BASE;
|
EDGE_SUCC (cond_block, 0)->probability = REG_BR_PROB_BASE;
|
EDGE_SUCC (cond_block, 0)->count += EDGE_SUCC (cond_block, 1)->count;
|
EDGE_SUCC (cond_block, 0)->count += EDGE_SUCC (cond_block, 1)->count;
|
|
|
block_to_remove = EDGE_SUCC (cond_block, 1)->dest;
|
block_to_remove = EDGE_SUCC (cond_block, 1)->dest;
|
}
|
}
|
else
|
else
|
{
|
{
|
EDGE_SUCC (cond_block, 1)->flags |= EDGE_FALLTHRU;
|
EDGE_SUCC (cond_block, 1)->flags |= EDGE_FALLTHRU;
|
EDGE_SUCC (cond_block, 1)->flags
|
EDGE_SUCC (cond_block, 1)->flags
|
&= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE);
|
&= ~(EDGE_TRUE_VALUE | EDGE_FALSE_VALUE);
|
EDGE_SUCC (cond_block, 1)->probability = REG_BR_PROB_BASE;
|
EDGE_SUCC (cond_block, 1)->probability = REG_BR_PROB_BASE;
|
EDGE_SUCC (cond_block, 1)->count += EDGE_SUCC (cond_block, 0)->count;
|
EDGE_SUCC (cond_block, 1)->count += EDGE_SUCC (cond_block, 0)->count;
|
|
|
block_to_remove = EDGE_SUCC (cond_block, 0)->dest;
|
block_to_remove = EDGE_SUCC (cond_block, 0)->dest;
|
}
|
}
|
delete_basic_block (block_to_remove);
|
delete_basic_block (block_to_remove);
|
|
|
/* Eliminate the COND_EXPR at the end of COND_BLOCK. */
|
/* Eliminate the COND_EXPR at the end of COND_BLOCK. */
|
gsi = gsi_last_bb (cond_block);
|
gsi = gsi_last_bb (cond_block);
|
gsi_remove (&gsi, true);
|
gsi_remove (&gsi, true);
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
fprintf (dump_file,
|
fprintf (dump_file,
|
"COND_EXPR in block %d and PHI in block %d converted to straightline code.\n",
|
"COND_EXPR in block %d and PHI in block %d converted to straightline code.\n",
|
cond_block->index,
|
cond_block->index,
|
bb->index);
|
bb->index);
|
}
|
}
|
|
|
/* The function conditional_replacement does the main work of doing the
|
/* The function conditional_replacement does the main work of doing the
|
conditional replacement. Return true if the replacement is done.
|
conditional replacement. Return true if the replacement is done.
|
Otherwise return false.
|
Otherwise return false.
|
BB is the basic block where the replacement is going to be done on. ARG0
|
BB is the basic block where the replacement is going to be done on. ARG0
|
is argument 0 from PHI. Likewise for ARG1. */
|
is argument 0 from PHI. Likewise for ARG1. */
|
|
|
static bool
|
static bool
|
conditional_replacement (basic_block cond_bb, basic_block middle_bb,
|
conditional_replacement (basic_block cond_bb, basic_block middle_bb,
|
edge e0, edge e1, gimple phi,
|
edge e0, edge e1, gimple phi,
|
tree arg0, tree arg1)
|
tree arg0, tree arg1)
|
{
|
{
|
tree result;
|
tree result;
|
gimple stmt, new_stmt;
|
gimple stmt, new_stmt;
|
tree cond;
|
tree cond;
|
gimple_stmt_iterator gsi;
|
gimple_stmt_iterator gsi;
|
edge true_edge, false_edge;
|
edge true_edge, false_edge;
|
tree new_var, new_var2;
|
tree new_var, new_var2;
|
|
|
/* FIXME: Gimplification of complex type is too hard for now. */
|
/* FIXME: Gimplification of complex type is too hard for now. */
|
if (TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
|
if (TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
|
|| TREE_CODE (TREE_TYPE (arg1)) == COMPLEX_TYPE)
|
|| TREE_CODE (TREE_TYPE (arg1)) == COMPLEX_TYPE)
|
return false;
|
return false;
|
|
|
/* The PHI arguments have the constants 0 and 1, then convert
|
/* The PHI arguments have the constants 0 and 1, then convert
|
it to the conditional. */
|
it to the conditional. */
|
if ((integer_zerop (arg0) && integer_onep (arg1))
|
if ((integer_zerop (arg0) && integer_onep (arg1))
|
|| (integer_zerop (arg1) && integer_onep (arg0)))
|
|| (integer_zerop (arg1) && integer_onep (arg0)))
|
;
|
;
|
else
|
else
|
return false;
|
return false;
|
|
|
if (!empty_block_p (middle_bb))
|
if (!empty_block_p (middle_bb))
|
return false;
|
return false;
|
|
|
/* At this point we know we have a GIMPLE_COND with two successors.
|
/* At this point we know we have a GIMPLE_COND with two successors.
|
One successor is BB, the other successor is an empty block which
|
One successor is BB, the other successor is an empty block which
|
falls through into BB.
|
falls through into BB.
|
|
|
There is a single PHI node at the join point (BB) and its arguments
|
There is a single PHI node at the join point (BB) and its arguments
|
are constants (0, 1).
|
are constants (0, 1).
|
|
|
So, given the condition COND, and the two PHI arguments, we can
|
So, given the condition COND, and the two PHI arguments, we can
|
rewrite this PHI into non-branching code:
|
rewrite this PHI into non-branching code:
|
|
|
dest = (COND) or dest = COND'
|
dest = (COND) or dest = COND'
|
|
|
We use the condition as-is if the argument associated with the
|
We use the condition as-is if the argument associated with the
|
true edge has the value one or the argument associated with the
|
true edge has the value one or the argument associated with the
|
false edge as the value zero. Note that those conditions are not
|
false edge as the value zero. Note that those conditions are not
|
the same since only one of the outgoing edges from the GIMPLE_COND
|
the same since only one of the outgoing edges from the GIMPLE_COND
|
will directly reach BB and thus be associated with an argument. */
|
will directly reach BB and thus be associated with an argument. */
|
|
|
stmt = last_stmt (cond_bb);
|
stmt = last_stmt (cond_bb);
|
result = PHI_RESULT (phi);
|
result = PHI_RESULT (phi);
|
|
|
/* To handle special cases like floating point comparison, it is easier and
|
/* To handle special cases like floating point comparison, it is easier and
|
less error-prone to build a tree and gimplify it on the fly though it is
|
less error-prone to build a tree and gimplify it on the fly though it is
|
less efficient. */
|
less efficient. */
|
cond = fold_build2 (gimple_cond_code (stmt), boolean_type_node,
|
cond = fold_build2 (gimple_cond_code (stmt), boolean_type_node,
|
gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
|
gimple_cond_lhs (stmt), gimple_cond_rhs (stmt));
|
|
|
/* We need to know which is the true edge and which is the false
|
/* We need to know which is the true edge and which is the false
|
edge so that we know when to invert the condition below. */
|
edge so that we know when to invert the condition below. */
|
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
|
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
|
if ((e0 == true_edge && integer_zerop (arg0))
|
if ((e0 == true_edge && integer_zerop (arg0))
|
|| (e0 == false_edge && integer_onep (arg0))
|
|| (e0 == false_edge && integer_onep (arg0))
|
|| (e1 == true_edge && integer_zerop (arg1))
|
|| (e1 == true_edge && integer_zerop (arg1))
|
|| (e1 == false_edge && integer_onep (arg1)))
|
|| (e1 == false_edge && integer_onep (arg1)))
|
cond = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (cond), cond);
|
cond = fold_build1 (TRUTH_NOT_EXPR, TREE_TYPE (cond), cond);
|
|
|
/* Insert our new statements at the end of conditional block before the
|
/* Insert our new statements at the end of conditional block before the
|
COND_STMT. */
|
COND_STMT. */
|
gsi = gsi_for_stmt (stmt);
|
gsi = gsi_for_stmt (stmt);
|
new_var = force_gimple_operand_gsi (&gsi, cond, true, NULL, true,
|
new_var = force_gimple_operand_gsi (&gsi, cond, true, NULL, true,
|
GSI_SAME_STMT);
|
GSI_SAME_STMT);
|
|
|
if (!useless_type_conversion_p (TREE_TYPE (result), TREE_TYPE (new_var)))
|
if (!useless_type_conversion_p (TREE_TYPE (result), TREE_TYPE (new_var)))
|
{
|
{
|
source_location locus_0, locus_1;
|
source_location locus_0, locus_1;
|
|
|
new_var2 = create_tmp_var (TREE_TYPE (result), NULL);
|
new_var2 = create_tmp_var (TREE_TYPE (result), NULL);
|
add_referenced_var (new_var2);
|
add_referenced_var (new_var2);
|
new_stmt = gimple_build_assign_with_ops (CONVERT_EXPR, new_var2,
|
new_stmt = gimple_build_assign_with_ops (CONVERT_EXPR, new_var2,
|
new_var, NULL);
|
new_var, NULL);
|
new_var2 = make_ssa_name (new_var2, new_stmt);
|
new_var2 = make_ssa_name (new_var2, new_stmt);
|
gimple_assign_set_lhs (new_stmt, new_var2);
|
gimple_assign_set_lhs (new_stmt, new_var2);
|
gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
|
gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
|
new_var = new_var2;
|
new_var = new_var2;
|
|
|
/* Set the locus to the first argument, unless is doesn't have one. */
|
/* Set the locus to the first argument, unless is doesn't have one. */
|
locus_0 = gimple_phi_arg_location (phi, 0);
|
locus_0 = gimple_phi_arg_location (phi, 0);
|
locus_1 = gimple_phi_arg_location (phi, 1);
|
locus_1 = gimple_phi_arg_location (phi, 1);
|
if (locus_0 == UNKNOWN_LOCATION)
|
if (locus_0 == UNKNOWN_LOCATION)
|
locus_0 = locus_1;
|
locus_0 = locus_1;
|
gimple_set_location (new_stmt, locus_0);
|
gimple_set_location (new_stmt, locus_0);
|
}
|
}
|
|
|
replace_phi_edge_with_variable (cond_bb, e1, phi, new_var);
|
replace_phi_edge_with_variable (cond_bb, e1, phi, new_var);
|
|
|
/* Note that we optimized this PHI. */
|
/* Note that we optimized this PHI. */
|
return true;
|
return true;
|
}
|
}
|
|
|
/* The function value_replacement does the main work of doing the value
|
/* The function value_replacement does the main work of doing the value
|
replacement. Return true if the replacement is done. Otherwise return
|
replacement. Return true if the replacement is done. Otherwise return
|
false.
|
false.
|
BB is the basic block where the replacement is going to be done on. ARG0
|
BB is the basic block where the replacement is going to be done on. ARG0
|
is argument 0 from the PHI. Likewise for ARG1. */
|
is argument 0 from the PHI. Likewise for ARG1. */
|
|
|
static bool
|
static bool
|
value_replacement (basic_block cond_bb, basic_block middle_bb,
|
value_replacement (basic_block cond_bb, basic_block middle_bb,
|
edge e0, edge e1, gimple phi,
|
edge e0, edge e1, gimple phi,
|
tree arg0, tree arg1)
|
tree arg0, tree arg1)
|
{
|
{
|
gimple cond;
|
gimple cond;
|
edge true_edge, false_edge;
|
edge true_edge, false_edge;
|
enum tree_code code;
|
enum tree_code code;
|
|
|
/* If the type says honor signed zeros we cannot do this
|
/* If the type says honor signed zeros we cannot do this
|
optimization. */
|
optimization. */
|
if (HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
|
if (HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
|
return false;
|
return false;
|
|
|
if (!empty_block_p (middle_bb))
|
if (!empty_block_p (middle_bb))
|
return false;
|
return false;
|
|
|
cond = last_stmt (cond_bb);
|
cond = last_stmt (cond_bb);
|
code = gimple_cond_code (cond);
|
code = gimple_cond_code (cond);
|
|
|
/* This transformation is only valid for equality comparisons. */
|
/* This transformation is only valid for equality comparisons. */
|
if (code != NE_EXPR && code != EQ_EXPR)
|
if (code != NE_EXPR && code != EQ_EXPR)
|
return false;
|
return false;
|
|
|
/* We need to know which is the true edge and which is the false
|
/* We need to know which is the true edge and which is the false
|
edge so that we know if have abs or negative abs. */
|
edge so that we know if have abs or negative abs. */
|
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
|
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
|
|
|
/* At this point we know we have a COND_EXPR with two successors.
|
/* At this point we know we have a COND_EXPR with two successors.
|
One successor is BB, the other successor is an empty block which
|
One successor is BB, the other successor is an empty block which
|
falls through into BB.
|
falls through into BB.
|
|
|
The condition for the COND_EXPR is known to be NE_EXPR or EQ_EXPR.
|
The condition for the COND_EXPR is known to be NE_EXPR or EQ_EXPR.
|
|
|
There is a single PHI node at the join point (BB) with two arguments.
|
There is a single PHI node at the join point (BB) with two arguments.
|
|
|
We now need to verify that the two arguments in the PHI node match
|
We now need to verify that the two arguments in the PHI node match
|
the two arguments to the equality comparison. */
|
the two arguments to the equality comparison. */
|
|
|
if ((operand_equal_for_phi_arg_p (arg0, gimple_cond_lhs (cond))
|
if ((operand_equal_for_phi_arg_p (arg0, gimple_cond_lhs (cond))
|
&& operand_equal_for_phi_arg_p (arg1, gimple_cond_rhs (cond)))
|
&& operand_equal_for_phi_arg_p (arg1, gimple_cond_rhs (cond)))
|
|| (operand_equal_for_phi_arg_p (arg1, gimple_cond_lhs (cond))
|
|| (operand_equal_for_phi_arg_p (arg1, gimple_cond_lhs (cond))
|
&& operand_equal_for_phi_arg_p (arg0, gimple_cond_rhs (cond))))
|
&& operand_equal_for_phi_arg_p (arg0, gimple_cond_rhs (cond))))
|
{
|
{
|
edge e;
|
edge e;
|
tree arg;
|
tree arg;
|
|
|
/* For NE_EXPR, we want to build an assignment result = arg where
|
/* For NE_EXPR, we want to build an assignment result = arg where
|
arg is the PHI argument associated with the true edge. For
|
arg is the PHI argument associated with the true edge. For
|
EQ_EXPR we want the PHI argument associated with the false edge. */
|
EQ_EXPR we want the PHI argument associated with the false edge. */
|
e = (code == NE_EXPR ? true_edge : false_edge);
|
e = (code == NE_EXPR ? true_edge : false_edge);
|
|
|
/* Unfortunately, E may not reach BB (it may instead have gone to
|
/* Unfortunately, E may not reach BB (it may instead have gone to
|
OTHER_BLOCK). If that is the case, then we want the single outgoing
|
OTHER_BLOCK). If that is the case, then we want the single outgoing
|
edge from OTHER_BLOCK which reaches BB and represents the desired
|
edge from OTHER_BLOCK which reaches BB and represents the desired
|
path from COND_BLOCK. */
|
path from COND_BLOCK. */
|
if (e->dest == middle_bb)
|
if (e->dest == middle_bb)
|
e = single_succ_edge (e->dest);
|
e = single_succ_edge (e->dest);
|
|
|
/* Now we know the incoming edge to BB that has the argument for the
|
/* Now we know the incoming edge to BB that has the argument for the
|
RHS of our new assignment statement. */
|
RHS of our new assignment statement. */
|
if (e0 == e)
|
if (e0 == e)
|
arg = arg0;
|
arg = arg0;
|
else
|
else
|
arg = arg1;
|
arg = arg1;
|
|
|
replace_phi_edge_with_variable (cond_bb, e1, phi, arg);
|
replace_phi_edge_with_variable (cond_bb, e1, phi, arg);
|
|
|
/* Note that we optimized this PHI. */
|
/* Note that we optimized this PHI. */
|
return true;
|
return true;
|
}
|
}
|
return false;
|
return false;
|
}
|
}
|
|
|
/* The function minmax_replacement does the main work of doing the minmax
|
/* The function minmax_replacement does the main work of doing the minmax
|
replacement. Return true if the replacement is done. Otherwise return
|
replacement. Return true if the replacement is done. Otherwise return
|
false.
|
false.
|
BB is the basic block where the replacement is going to be done on. ARG0
|
BB is the basic block where the replacement is going to be done on. ARG0
|
is argument 0 from the PHI. Likewise for ARG1. */
|
is argument 0 from the PHI. Likewise for ARG1. */
|
|
|
static bool
|
static bool
|
minmax_replacement (basic_block cond_bb, basic_block middle_bb,
|
minmax_replacement (basic_block cond_bb, basic_block middle_bb,
|
edge e0, edge e1, gimple phi,
|
edge e0, edge e1, gimple phi,
|
tree arg0, tree arg1)
|
tree arg0, tree arg1)
|
{
|
{
|
tree result, type;
|
tree result, type;
|
gimple cond, new_stmt;
|
gimple cond, new_stmt;
|
edge true_edge, false_edge;
|
edge true_edge, false_edge;
|
enum tree_code cmp, minmax, ass_code;
|
enum tree_code cmp, minmax, ass_code;
|
tree smaller, larger, arg_true, arg_false;
|
tree smaller, larger, arg_true, arg_false;
|
gimple_stmt_iterator gsi, gsi_from;
|
gimple_stmt_iterator gsi, gsi_from;
|
|
|
type = TREE_TYPE (PHI_RESULT (phi));
|
type = TREE_TYPE (PHI_RESULT (phi));
|
|
|
/* The optimization may be unsafe due to NaNs. */
|
/* The optimization may be unsafe due to NaNs. */
|
if (HONOR_NANS (TYPE_MODE (type)))
|
if (HONOR_NANS (TYPE_MODE (type)))
|
return false;
|
return false;
|
|
|
cond = last_stmt (cond_bb);
|
cond = last_stmt (cond_bb);
|
cmp = gimple_cond_code (cond);
|
cmp = gimple_cond_code (cond);
|
result = PHI_RESULT (phi);
|
result = PHI_RESULT (phi);
|
|
|
/* This transformation is only valid for order comparisons. Record which
|
/* This transformation is only valid for order comparisons. Record which
|
operand is smaller/larger if the result of the comparison is true. */
|
operand is smaller/larger if the result of the comparison is true. */
|
if (cmp == LT_EXPR || cmp == LE_EXPR)
|
if (cmp == LT_EXPR || cmp == LE_EXPR)
|
{
|
{
|
smaller = gimple_cond_lhs (cond);
|
smaller = gimple_cond_lhs (cond);
|
larger = gimple_cond_rhs (cond);
|
larger = gimple_cond_rhs (cond);
|
}
|
}
|
else if (cmp == GT_EXPR || cmp == GE_EXPR)
|
else if (cmp == GT_EXPR || cmp == GE_EXPR)
|
{
|
{
|
smaller = gimple_cond_rhs (cond);
|
smaller = gimple_cond_rhs (cond);
|
larger = gimple_cond_lhs (cond);
|
larger = gimple_cond_lhs (cond);
|
}
|
}
|
else
|
else
|
return false;
|
return false;
|
|
|
/* We need to know which is the true edge and which is the false
|
/* We need to know which is the true edge and which is the false
|
edge so that we know if have abs or negative abs. */
|
edge so that we know if have abs or negative abs. */
|
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
|
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
|
|
|
/* Forward the edges over the middle basic block. */
|
/* Forward the edges over the middle basic block. */
|
if (true_edge->dest == middle_bb)
|
if (true_edge->dest == middle_bb)
|
true_edge = EDGE_SUCC (true_edge->dest, 0);
|
true_edge = EDGE_SUCC (true_edge->dest, 0);
|
if (false_edge->dest == middle_bb)
|
if (false_edge->dest == middle_bb)
|
false_edge = EDGE_SUCC (false_edge->dest, 0);
|
false_edge = EDGE_SUCC (false_edge->dest, 0);
|
|
|
if (true_edge == e0)
|
if (true_edge == e0)
|
{
|
{
|
gcc_assert (false_edge == e1);
|
gcc_assert (false_edge == e1);
|
arg_true = arg0;
|
arg_true = arg0;
|
arg_false = arg1;
|
arg_false = arg1;
|
}
|
}
|
else
|
else
|
{
|
{
|
gcc_assert (false_edge == e0);
|
gcc_assert (false_edge == e0);
|
gcc_assert (true_edge == e1);
|
gcc_assert (true_edge == e1);
|
arg_true = arg1;
|
arg_true = arg1;
|
arg_false = arg0;
|
arg_false = arg0;
|
}
|
}
|
|
|
if (empty_block_p (middle_bb))
|
if (empty_block_p (middle_bb))
|
{
|
{
|
if (operand_equal_for_phi_arg_p (arg_true, smaller)
|
if (operand_equal_for_phi_arg_p (arg_true, smaller)
|
&& operand_equal_for_phi_arg_p (arg_false, larger))
|
&& operand_equal_for_phi_arg_p (arg_false, larger))
|
{
|
{
|
/* Case
|
/* Case
|
|
|
if (smaller < larger)
|
if (smaller < larger)
|
rslt = smaller;
|
rslt = smaller;
|
else
|
else
|
rslt = larger; */
|
rslt = larger; */
|
minmax = MIN_EXPR;
|
minmax = MIN_EXPR;
|
}
|
}
|
else if (operand_equal_for_phi_arg_p (arg_false, smaller)
|
else if (operand_equal_for_phi_arg_p (arg_false, smaller)
|
&& operand_equal_for_phi_arg_p (arg_true, larger))
|
&& operand_equal_for_phi_arg_p (arg_true, larger))
|
minmax = MAX_EXPR;
|
minmax = MAX_EXPR;
|
else
|
else
|
return false;
|
return false;
|
}
|
}
|
else
|
else
|
{
|
{
|
/* Recognize the following case, assuming d <= u:
|
/* Recognize the following case, assuming d <= u:
|
|
|
if (a <= u)
|
if (a <= u)
|
b = MAX (a, d);
|
b = MAX (a, d);
|
x = PHI <b, u>
|
x = PHI <b, u>
|
|
|
This is equivalent to
|
This is equivalent to
|
|
|
b = MAX (a, d);
|
b = MAX (a, d);
|
x = MIN (b, u); */
|
x = MIN (b, u); */
|
|
|
gimple assign = last_and_only_stmt (middle_bb);
|
gimple assign = last_and_only_stmt (middle_bb);
|
tree lhs, op0, op1, bound;
|
tree lhs, op0, op1, bound;
|
|
|
if (!assign
|
if (!assign
|
|| gimple_code (assign) != GIMPLE_ASSIGN)
|
|| gimple_code (assign) != GIMPLE_ASSIGN)
|
return false;
|
return false;
|
|
|
lhs = gimple_assign_lhs (assign);
|
lhs = gimple_assign_lhs (assign);
|
ass_code = gimple_assign_rhs_code (assign);
|
ass_code = gimple_assign_rhs_code (assign);
|
if (ass_code != MAX_EXPR && ass_code != MIN_EXPR)
|
if (ass_code != MAX_EXPR && ass_code != MIN_EXPR)
|
return false;
|
return false;
|
op0 = gimple_assign_rhs1 (assign);
|
op0 = gimple_assign_rhs1 (assign);
|
op1 = gimple_assign_rhs2 (assign);
|
op1 = gimple_assign_rhs2 (assign);
|
|
|
if (true_edge->src == middle_bb)
|
if (true_edge->src == middle_bb)
|
{
|
{
|
/* We got here if the condition is true, i.e., SMALLER < LARGER. */
|
/* We got here if the condition is true, i.e., SMALLER < LARGER. */
|
if (!operand_equal_for_phi_arg_p (lhs, arg_true))
|
if (!operand_equal_for_phi_arg_p (lhs, arg_true))
|
return false;
|
return false;
|
|
|
if (operand_equal_for_phi_arg_p (arg_false, larger))
|
if (operand_equal_for_phi_arg_p (arg_false, larger))
|
{
|
{
|
/* Case
|
/* Case
|
|
|
if (smaller < larger)
|
if (smaller < larger)
|
{
|
{
|
r' = MAX_EXPR (smaller, bound)
|
r' = MAX_EXPR (smaller, bound)
|
}
|
}
|
r = PHI <r', larger> --> to be turned to MIN_EXPR. */
|
r = PHI <r', larger> --> to be turned to MIN_EXPR. */
|
if (ass_code != MAX_EXPR)
|
if (ass_code != MAX_EXPR)
|
return false;
|
return false;
|
|
|
minmax = MIN_EXPR;
|
minmax = MIN_EXPR;
|
if (operand_equal_for_phi_arg_p (op0, smaller))
|
if (operand_equal_for_phi_arg_p (op0, smaller))
|
bound = op1;
|
bound = op1;
|
else if (operand_equal_for_phi_arg_p (op1, smaller))
|
else if (operand_equal_for_phi_arg_p (op1, smaller))
|
bound = op0;
|
bound = op0;
|
else
|
else
|
return false;
|
return false;
|
|
|
/* We need BOUND <= LARGER. */
|
/* We need BOUND <= LARGER. */
|
if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node,
|
if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node,
|
bound, larger)))
|
bound, larger)))
|
return false;
|
return false;
|
}
|
}
|
else if (operand_equal_for_phi_arg_p (arg_false, smaller))
|
else if (operand_equal_for_phi_arg_p (arg_false, smaller))
|
{
|
{
|
/* Case
|
/* Case
|
|
|
if (smaller < larger)
|
if (smaller < larger)
|
{
|
{
|
r' = MIN_EXPR (larger, bound)
|
r' = MIN_EXPR (larger, bound)
|
}
|
}
|
r = PHI <r', smaller> --> to be turned to MAX_EXPR. */
|
r = PHI <r', smaller> --> to be turned to MAX_EXPR. */
|
if (ass_code != MIN_EXPR)
|
if (ass_code != MIN_EXPR)
|
return false;
|
return false;
|
|
|
minmax = MAX_EXPR;
|
minmax = MAX_EXPR;
|
if (operand_equal_for_phi_arg_p (op0, larger))
|
if (operand_equal_for_phi_arg_p (op0, larger))
|
bound = op1;
|
bound = op1;
|
else if (operand_equal_for_phi_arg_p (op1, larger))
|
else if (operand_equal_for_phi_arg_p (op1, larger))
|
bound = op0;
|
bound = op0;
|
else
|
else
|
return false;
|
return false;
|
|
|
/* We need BOUND >= SMALLER. */
|
/* We need BOUND >= SMALLER. */
|
if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node,
|
if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node,
|
bound, smaller)))
|
bound, smaller)))
|
return false;
|
return false;
|
}
|
}
|
else
|
else
|
return false;
|
return false;
|
}
|
}
|
else
|
else
|
{
|
{
|
/* We got here if the condition is false, i.e., SMALLER > LARGER. */
|
/* We got here if the condition is false, i.e., SMALLER > LARGER. */
|
if (!operand_equal_for_phi_arg_p (lhs, arg_false))
|
if (!operand_equal_for_phi_arg_p (lhs, arg_false))
|
return false;
|
return false;
|
|
|
if (operand_equal_for_phi_arg_p (arg_true, larger))
|
if (operand_equal_for_phi_arg_p (arg_true, larger))
|
{
|
{
|
/* Case
|
/* Case
|
|
|
if (smaller > larger)
|
if (smaller > larger)
|
{
|
{
|
r' = MIN_EXPR (smaller, bound)
|
r' = MIN_EXPR (smaller, bound)
|
}
|
}
|
r = PHI <r', larger> --> to be turned to MAX_EXPR. */
|
r = PHI <r', larger> --> to be turned to MAX_EXPR. */
|
if (ass_code != MIN_EXPR)
|
if (ass_code != MIN_EXPR)
|
return false;
|
return false;
|
|
|
minmax = MAX_EXPR;
|
minmax = MAX_EXPR;
|
if (operand_equal_for_phi_arg_p (op0, smaller))
|
if (operand_equal_for_phi_arg_p (op0, smaller))
|
bound = op1;
|
bound = op1;
|
else if (operand_equal_for_phi_arg_p (op1, smaller))
|
else if (operand_equal_for_phi_arg_p (op1, smaller))
|
bound = op0;
|
bound = op0;
|
else
|
else
|
return false;
|
return false;
|
|
|
/* We need BOUND >= LARGER. */
|
/* We need BOUND >= LARGER. */
|
if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node,
|
if (!integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node,
|
bound, larger)))
|
bound, larger)))
|
return false;
|
return false;
|
}
|
}
|
else if (operand_equal_for_phi_arg_p (arg_true, smaller))
|
else if (operand_equal_for_phi_arg_p (arg_true, smaller))
|
{
|
{
|
/* Case
|
/* Case
|
|
|
if (smaller > larger)
|
if (smaller > larger)
|
{
|
{
|
r' = MAX_EXPR (larger, bound)
|
r' = MAX_EXPR (larger, bound)
|
}
|
}
|
r = PHI <r', smaller> --> to be turned to MIN_EXPR. */
|
r = PHI <r', smaller> --> to be turned to MIN_EXPR. */
|
if (ass_code != MAX_EXPR)
|
if (ass_code != MAX_EXPR)
|
return false;
|
return false;
|
|
|
minmax = MIN_EXPR;
|
minmax = MIN_EXPR;
|
if (operand_equal_for_phi_arg_p (op0, larger))
|
if (operand_equal_for_phi_arg_p (op0, larger))
|
bound = op1;
|
bound = op1;
|
else if (operand_equal_for_phi_arg_p (op1, larger))
|
else if (operand_equal_for_phi_arg_p (op1, larger))
|
bound = op0;
|
bound = op0;
|
else
|
else
|
return false;
|
return false;
|
|
|
/* We need BOUND <= SMALLER. */
|
/* We need BOUND <= SMALLER. */
|
if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node,
|
if (!integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node,
|
bound, smaller)))
|
bound, smaller)))
|
return false;
|
return false;
|
}
|
}
|
else
|
else
|
return false;
|
return false;
|
}
|
}
|
|
|
/* Move the statement from the middle block. */
|
/* Move the statement from the middle block. */
|
gsi = gsi_last_bb (cond_bb);
|
gsi = gsi_last_bb (cond_bb);
|
gsi_from = gsi_last_nondebug_bb (middle_bb);
|
gsi_from = gsi_last_nondebug_bb (middle_bb);
|
gsi_move_before (&gsi_from, &gsi);
|
gsi_move_before (&gsi_from, &gsi);
|
}
|
}
|
|
|
/* Emit the statement to compute min/max. */
|
/* Emit the statement to compute min/max. */
|
result = duplicate_ssa_name (PHI_RESULT (phi), NULL);
|
result = duplicate_ssa_name (PHI_RESULT (phi), NULL);
|
new_stmt = gimple_build_assign_with_ops (minmax, result, arg0, arg1);
|
new_stmt = gimple_build_assign_with_ops (minmax, result, arg0, arg1);
|
gsi = gsi_last_bb (cond_bb);
|
gsi = gsi_last_bb (cond_bb);
|
gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT);
|
gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT);
|
|
|
replace_phi_edge_with_variable (cond_bb, e1, phi, result);
|
replace_phi_edge_with_variable (cond_bb, e1, phi, result);
|
return true;
|
return true;
|
}
|
}
|
|
|
/* The function absolute_replacement does the main work of doing the absolute
|
/* The function absolute_replacement does the main work of doing the absolute
|
replacement. Return true if the replacement is done. Otherwise return
|
replacement. Return true if the replacement is done. Otherwise return
|
false.
|
false.
|
bb is the basic block where the replacement is going to be done on. arg0
|
bb is the basic block where the replacement is going to be done on. arg0
|
is argument 0 from the phi. Likewise for arg1. */
|
is argument 0 from the phi. Likewise for arg1. */
|
|
|
static bool
|
static bool
|
abs_replacement (basic_block cond_bb, basic_block middle_bb,
|
abs_replacement (basic_block cond_bb, basic_block middle_bb,
|
edge e0 ATTRIBUTE_UNUSED, edge e1,
|
edge e0 ATTRIBUTE_UNUSED, edge e1,
|
gimple phi, tree arg0, tree arg1)
|
gimple phi, tree arg0, tree arg1)
|
{
|
{
|
tree result;
|
tree result;
|
gimple new_stmt, cond;
|
gimple new_stmt, cond;
|
gimple_stmt_iterator gsi;
|
gimple_stmt_iterator gsi;
|
edge true_edge, false_edge;
|
edge true_edge, false_edge;
|
gimple assign;
|
gimple assign;
|
edge e;
|
edge e;
|
tree rhs, lhs;
|
tree rhs, lhs;
|
bool negate;
|
bool negate;
|
enum tree_code cond_code;
|
enum tree_code cond_code;
|
|
|
/* If the type says honor signed zeros we cannot do this
|
/* If the type says honor signed zeros we cannot do this
|
optimization. */
|
optimization. */
|
if (HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
|
if (HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
|
return false;
|
return false;
|
|
|
/* OTHER_BLOCK must have only one executable statement which must have the
|
/* OTHER_BLOCK must have only one executable statement which must have the
|
form arg0 = -arg1 or arg1 = -arg0. */
|
form arg0 = -arg1 or arg1 = -arg0. */
|
|
|
assign = last_and_only_stmt (middle_bb);
|
assign = last_and_only_stmt (middle_bb);
|
/* If we did not find the proper negation assignment, then we can not
|
/* If we did not find the proper negation assignment, then we can not
|
optimize. */
|
optimize. */
|
if (assign == NULL)
|
if (assign == NULL)
|
return false;
|
return false;
|
|
|
/* If we got here, then we have found the only executable statement
|
/* If we got here, then we have found the only executable statement
|
in OTHER_BLOCK. If it is anything other than arg = -arg1 or
|
in OTHER_BLOCK. If it is anything other than arg = -arg1 or
|
arg1 = -arg0, then we can not optimize. */
|
arg1 = -arg0, then we can not optimize. */
|
if (gimple_code (assign) != GIMPLE_ASSIGN)
|
if (gimple_code (assign) != GIMPLE_ASSIGN)
|
return false;
|
return false;
|
|
|
lhs = gimple_assign_lhs (assign);
|
lhs = gimple_assign_lhs (assign);
|
|
|
if (gimple_assign_rhs_code (assign) != NEGATE_EXPR)
|
if (gimple_assign_rhs_code (assign) != NEGATE_EXPR)
|
return false;
|
return false;
|
|
|
rhs = gimple_assign_rhs1 (assign);
|
rhs = gimple_assign_rhs1 (assign);
|
|
|
/* The assignment has to be arg0 = -arg1 or arg1 = -arg0. */
|
/* The assignment has to be arg0 = -arg1 or arg1 = -arg0. */
|
if (!(lhs == arg0 && rhs == arg1)
|
if (!(lhs == arg0 && rhs == arg1)
|
&& !(lhs == arg1 && rhs == arg0))
|
&& !(lhs == arg1 && rhs == arg0))
|
return false;
|
return false;
|
|
|
cond = last_stmt (cond_bb);
|
cond = last_stmt (cond_bb);
|
result = PHI_RESULT (phi);
|
result = PHI_RESULT (phi);
|
|
|
/* Only relationals comparing arg[01] against zero are interesting. */
|
/* Only relationals comparing arg[01] against zero are interesting. */
|
cond_code = gimple_cond_code (cond);
|
cond_code = gimple_cond_code (cond);
|
if (cond_code != GT_EXPR && cond_code != GE_EXPR
|
if (cond_code != GT_EXPR && cond_code != GE_EXPR
|
&& cond_code != LT_EXPR && cond_code != LE_EXPR)
|
&& cond_code != LT_EXPR && cond_code != LE_EXPR)
|
return false;
|
return false;
|
|
|
/* Make sure the conditional is arg[01] OP y. */
|
/* Make sure the conditional is arg[01] OP y. */
|
if (gimple_cond_lhs (cond) != rhs)
|
if (gimple_cond_lhs (cond) != rhs)
|
return false;
|
return false;
|
|
|
if (FLOAT_TYPE_P (TREE_TYPE (gimple_cond_rhs (cond)))
|
if (FLOAT_TYPE_P (TREE_TYPE (gimple_cond_rhs (cond)))
|
? real_zerop (gimple_cond_rhs (cond))
|
? real_zerop (gimple_cond_rhs (cond))
|
: integer_zerop (gimple_cond_rhs (cond)))
|
: integer_zerop (gimple_cond_rhs (cond)))
|
;
|
;
|
else
|
else
|
return false;
|
return false;
|
|
|
/* We need to know which is the true edge and which is the false
|
/* We need to know which is the true edge and which is the false
|
edge so that we know if have abs or negative abs. */
|
edge so that we know if have abs or negative abs. */
|
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
|
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
|
|
|
/* For GT_EXPR/GE_EXPR, if the true edge goes to OTHER_BLOCK, then we
|
/* For GT_EXPR/GE_EXPR, if the true edge goes to OTHER_BLOCK, then we
|
will need to negate the result. Similarly for LT_EXPR/LE_EXPR if
|
will need to negate the result. Similarly for LT_EXPR/LE_EXPR if
|
the false edge goes to OTHER_BLOCK. */
|
the false edge goes to OTHER_BLOCK. */
|
if (cond_code == GT_EXPR || cond_code == GE_EXPR)
|
if (cond_code == GT_EXPR || cond_code == GE_EXPR)
|
e = true_edge;
|
e = true_edge;
|
else
|
else
|
e = false_edge;
|
e = false_edge;
|
|
|
if (e->dest == middle_bb)
|
if (e->dest == middle_bb)
|
negate = true;
|
negate = true;
|
else
|
else
|
negate = false;
|
negate = false;
|
|
|
result = duplicate_ssa_name (result, NULL);
|
result = duplicate_ssa_name (result, NULL);
|
|
|
if (negate)
|
if (negate)
|
{
|
{
|
tree tmp = create_tmp_var (TREE_TYPE (result), NULL);
|
tree tmp = create_tmp_var (TREE_TYPE (result), NULL);
|
add_referenced_var (tmp);
|
add_referenced_var (tmp);
|
lhs = make_ssa_name (tmp, NULL);
|
lhs = make_ssa_name (tmp, NULL);
|
}
|
}
|
else
|
else
|
lhs = result;
|
lhs = result;
|
|
|
/* Build the modify expression with abs expression. */
|
/* Build the modify expression with abs expression. */
|
new_stmt = gimple_build_assign_with_ops (ABS_EXPR, lhs, rhs, NULL);
|
new_stmt = gimple_build_assign_with_ops (ABS_EXPR, lhs, rhs, NULL);
|
|
|
gsi = gsi_last_bb (cond_bb);
|
gsi = gsi_last_bb (cond_bb);
|
gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT);
|
gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT);
|
|
|
if (negate)
|
if (negate)
|
{
|
{
|
/* Get the right GSI. We want to insert after the recently
|
/* Get the right GSI. We want to insert after the recently
|
added ABS_EXPR statement (which we know is the first statement
|
added ABS_EXPR statement (which we know is the first statement
|
in the block. */
|
in the block. */
|
new_stmt = gimple_build_assign_with_ops (NEGATE_EXPR, result, lhs, NULL);
|
new_stmt = gimple_build_assign_with_ops (NEGATE_EXPR, result, lhs, NULL);
|
|
|
gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT);
|
gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT);
|
}
|
}
|
|
|
replace_phi_edge_with_variable (cond_bb, e1, phi, result);
|
replace_phi_edge_with_variable (cond_bb, e1, phi, result);
|
|
|
/* Note that we optimized this PHI. */
|
/* Note that we optimized this PHI. */
|
return true;
|
return true;
|
}
|
}
|
|
|
/* Auxiliary functions to determine the set of memory accesses which
|
/* Auxiliary functions to determine the set of memory accesses which
|
can't trap because they are preceded by accesses to the same memory
|
can't trap because they are preceded by accesses to the same memory
|
portion. We do that for INDIRECT_REFs, so we only need to track
|
portion. We do that for INDIRECT_REFs, so we only need to track
|
the SSA_NAME of the pointer indirectly referenced. The algorithm
|
the SSA_NAME of the pointer indirectly referenced. The algorithm
|
simply is a walk over all instructions in dominator order. When
|
simply is a walk over all instructions in dominator order. When
|
we see an INDIRECT_REF we determine if we've already seen a same
|
we see an INDIRECT_REF we determine if we've already seen a same
|
ref anywhere up to the root of the dominator tree. If we do the
|
ref anywhere up to the root of the dominator tree. If we do the
|
current access can't trap. If we don't see any dominating access
|
current access can't trap. If we don't see any dominating access
|
the current access might trap, but might also make later accesses
|
the current access might trap, but might also make later accesses
|
non-trapping, so we remember it. We need to be careful with loads
|
non-trapping, so we remember it. We need to be careful with loads
|
or stores, for instance a load might not trap, while a store would,
|
or stores, for instance a load might not trap, while a store would,
|
so if we see a dominating read access this doesn't mean that a later
|
so if we see a dominating read access this doesn't mean that a later
|
write access would not trap. Hence we also need to differentiate the
|
write access would not trap. Hence we also need to differentiate the
|
type of access(es) seen.
|
type of access(es) seen.
|
|
|
??? We currently are very conservative and assume that a load might
|
??? We currently are very conservative and assume that a load might
|
trap even if a store doesn't (write-only memory). This probably is
|
trap even if a store doesn't (write-only memory). This probably is
|
overly conservative. */
|
overly conservative. */
|
|
|
/* A hash-table of SSA_NAMEs, and in which basic block an INDIRECT_REF
|
/* A hash-table of SSA_NAMEs, and in which basic block an INDIRECT_REF
|
through it was seen, which would constitute a no-trap region for
|
through it was seen, which would constitute a no-trap region for
|
same accesses. */
|
same accesses. */
|
struct name_to_bb
|
struct name_to_bb
|
{
|
{
|
tree ssa_name;
|
tree ssa_name;
|
basic_block bb;
|
basic_block bb;
|
unsigned store : 1;
|
unsigned store : 1;
|
};
|
};
|
|
|
/* The hash table for remembering what we've seen. */
|
/* The hash table for remembering what we've seen. */
|
static htab_t seen_ssa_names;
|
static htab_t seen_ssa_names;
|
|
|
/* The set of INDIRECT_REFs which can't trap. */
|
/* The set of INDIRECT_REFs which can't trap. */
|
static struct pointer_set_t *nontrap_set;
|
static struct pointer_set_t *nontrap_set;
|
|
|
/* The hash function, based on the pointer to the pointer SSA_NAME. */
|
/* The hash function, based on the pointer to the pointer SSA_NAME. */
|
static hashval_t
|
static hashval_t
|
name_to_bb_hash (const void *p)
|
name_to_bb_hash (const void *p)
|
{
|
{
|
const_tree n = ((const struct name_to_bb *)p)->ssa_name;
|
const_tree n = ((const struct name_to_bb *)p)->ssa_name;
|
return htab_hash_pointer (n) ^ ((const struct name_to_bb *)p)->store;
|
return htab_hash_pointer (n) ^ ((const struct name_to_bb *)p)->store;
|
}
|
}
|
|
|
/* The equality function of *P1 and *P2. SSA_NAMEs are shared, so
|
/* The equality function of *P1 and *P2. SSA_NAMEs are shared, so
|
it's enough to simply compare them for equality. */
|
it's enough to simply compare them for equality. */
|
static int
|
static int
|
name_to_bb_eq (const void *p1, const void *p2)
|
name_to_bb_eq (const void *p1, const void *p2)
|
{
|
{
|
const struct name_to_bb *n1 = (const struct name_to_bb *)p1;
|
const struct name_to_bb *n1 = (const struct name_to_bb *)p1;
|
const struct name_to_bb *n2 = (const struct name_to_bb *)p2;
|
const struct name_to_bb *n2 = (const struct name_to_bb *)p2;
|
|
|
return n1->ssa_name == n2->ssa_name && n1->store == n2->store;
|
return n1->ssa_name == n2->ssa_name && n1->store == n2->store;
|
}
|
}
|
|
|
/* We see the expression EXP in basic block BB. If it's an interesting
|
/* We see the expression EXP in basic block BB. If it's an interesting
|
expression (an INDIRECT_REF through an SSA_NAME) possibly insert the
|
expression (an INDIRECT_REF through an SSA_NAME) possibly insert the
|
expression into the set NONTRAP or the hash table of seen expressions.
|
expression into the set NONTRAP or the hash table of seen expressions.
|
STORE is true if this expression is on the LHS, otherwise it's on
|
STORE is true if this expression is on the LHS, otherwise it's on
|
the RHS. */
|
the RHS. */
|
static void
|
static void
|
add_or_mark_expr (basic_block bb, tree exp,
|
add_or_mark_expr (basic_block bb, tree exp,
|
struct pointer_set_t *nontrap, bool store)
|
struct pointer_set_t *nontrap, bool store)
|
{
|
{
|
if (INDIRECT_REF_P (exp)
|
if (INDIRECT_REF_P (exp)
|
&& TREE_CODE (TREE_OPERAND (exp, 0)) == SSA_NAME)
|
&& TREE_CODE (TREE_OPERAND (exp, 0)) == SSA_NAME)
|
{
|
{
|
tree name = TREE_OPERAND (exp, 0);
|
tree name = TREE_OPERAND (exp, 0);
|
struct name_to_bb map;
|
struct name_to_bb map;
|
void **slot;
|
void **slot;
|
struct name_to_bb *n2bb;
|
struct name_to_bb *n2bb;
|
basic_block found_bb = 0;
|
basic_block found_bb = 0;
|
|
|
/* Try to find the last seen INDIRECT_REF through the same
|
/* Try to find the last seen INDIRECT_REF through the same
|
SSA_NAME, which can trap. */
|
SSA_NAME, which can trap. */
|
map.ssa_name = name;
|
map.ssa_name = name;
|
map.bb = 0;
|
map.bb = 0;
|
map.store = store;
|
map.store = store;
|
slot = htab_find_slot (seen_ssa_names, &map, INSERT);
|
slot = htab_find_slot (seen_ssa_names, &map, INSERT);
|
n2bb = (struct name_to_bb *) *slot;
|
n2bb = (struct name_to_bb *) *slot;
|
if (n2bb)
|
if (n2bb)
|
found_bb = n2bb->bb;
|
found_bb = n2bb->bb;
|
|
|
/* If we've found a trapping INDIRECT_REF, _and_ it dominates EXP
|
/* If we've found a trapping INDIRECT_REF, _and_ it dominates EXP
|
(it's in a basic block on the path from us to the dominator root)
|
(it's in a basic block on the path from us to the dominator root)
|
then we can't trap. */
|
then we can't trap. */
|
if (found_bb && found_bb->aux == (void *)1)
|
if (found_bb && found_bb->aux == (void *)1)
|
{
|
{
|
pointer_set_insert (nontrap, exp);
|
pointer_set_insert (nontrap, exp);
|
}
|
}
|
else
|
else
|
{
|
{
|
/* EXP might trap, so insert it into the hash table. */
|
/* EXP might trap, so insert it into the hash table. */
|
if (n2bb)
|
if (n2bb)
|
{
|
{
|
n2bb->bb = bb;
|
n2bb->bb = bb;
|
}
|
}
|
else
|
else
|
{
|
{
|
n2bb = XNEW (struct name_to_bb);
|
n2bb = XNEW (struct name_to_bb);
|
n2bb->ssa_name = name;
|
n2bb->ssa_name = name;
|
n2bb->bb = bb;
|
n2bb->bb = bb;
|
n2bb->store = store;
|
n2bb->store = store;
|
*slot = n2bb;
|
*slot = n2bb;
|
}
|
}
|
}
|
}
|
}
|
}
|
}
|
}
|
|
|
/* Called by walk_dominator_tree, when entering the block BB. */
|
/* Called by walk_dominator_tree, when entering the block BB. */
|
static void
|
static void
|
nt_init_block (struct dom_walk_data *data ATTRIBUTE_UNUSED, basic_block bb)
|
nt_init_block (struct dom_walk_data *data ATTRIBUTE_UNUSED, basic_block bb)
|
{
|
{
|
gimple_stmt_iterator gsi;
|
gimple_stmt_iterator gsi;
|
/* Mark this BB as being on the path to dominator root. */
|
/* Mark this BB as being on the path to dominator root. */
|
bb->aux = (void*)1;
|
bb->aux = (void*)1;
|
|
|
/* And walk the statements in order. */
|
/* And walk the statements in order. */
|
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
{
|
{
|
gimple stmt = gsi_stmt (gsi);
|
gimple stmt = gsi_stmt (gsi);
|
|
|
if (is_gimple_assign (stmt))
|
if (is_gimple_assign (stmt))
|
{
|
{
|
add_or_mark_expr (bb, gimple_assign_lhs (stmt), nontrap_set, true);
|
add_or_mark_expr (bb, gimple_assign_lhs (stmt), nontrap_set, true);
|
add_or_mark_expr (bb, gimple_assign_rhs1 (stmt), nontrap_set, false);
|
add_or_mark_expr (bb, gimple_assign_rhs1 (stmt), nontrap_set, false);
|
if (get_gimple_rhs_num_ops (gimple_assign_rhs_code (stmt)) > 1)
|
if (get_gimple_rhs_num_ops (gimple_assign_rhs_code (stmt)) > 1)
|
add_or_mark_expr (bb, gimple_assign_rhs2 (stmt), nontrap_set,
|
add_or_mark_expr (bb, gimple_assign_rhs2 (stmt), nontrap_set,
|
false);
|
false);
|
}
|
}
|
}
|
}
|
}
|
}
|
|
|
/* Called by walk_dominator_tree, when basic block BB is exited. */
|
/* Called by walk_dominator_tree, when basic block BB is exited. */
|
static void
|
static void
|
nt_fini_block (struct dom_walk_data *data ATTRIBUTE_UNUSED, basic_block bb)
|
nt_fini_block (struct dom_walk_data *data ATTRIBUTE_UNUSED, basic_block bb)
|
{
|
{
|
/* This BB isn't on the path to dominator root anymore. */
|
/* This BB isn't on the path to dominator root anymore. */
|
bb->aux = NULL;
|
bb->aux = NULL;
|
}
|
}
|
|
|
/* This is the entry point of gathering non trapping memory accesses.
|
/* This is the entry point of gathering non trapping memory accesses.
|
It will do a dominator walk over the whole function, and it will
|
It will do a dominator walk over the whole function, and it will
|
make use of the bb->aux pointers. It returns a set of trees
|
make use of the bb->aux pointers. It returns a set of trees
|
(the INDIRECT_REFs itself) which can't trap. */
|
(the INDIRECT_REFs itself) which can't trap. */
|
static struct pointer_set_t *
|
static struct pointer_set_t *
|
get_non_trapping (void)
|
get_non_trapping (void)
|
{
|
{
|
struct pointer_set_t *nontrap;
|
struct pointer_set_t *nontrap;
|
struct dom_walk_data walk_data;
|
struct dom_walk_data walk_data;
|
|
|
nontrap = pointer_set_create ();
|
nontrap = pointer_set_create ();
|
seen_ssa_names = htab_create (128, name_to_bb_hash, name_to_bb_eq,
|
seen_ssa_names = htab_create (128, name_to_bb_hash, name_to_bb_eq,
|
free);
|
free);
|
/* We're going to do a dominator walk, so ensure that we have
|
/* We're going to do a dominator walk, so ensure that we have
|
dominance information. */
|
dominance information. */
|
calculate_dominance_info (CDI_DOMINATORS);
|
calculate_dominance_info (CDI_DOMINATORS);
|
|
|
/* Setup callbacks for the generic dominator tree walker. */
|
/* Setup callbacks for the generic dominator tree walker. */
|
nontrap_set = nontrap;
|
nontrap_set = nontrap;
|
walk_data.dom_direction = CDI_DOMINATORS;
|
walk_data.dom_direction = CDI_DOMINATORS;
|
walk_data.initialize_block_local_data = NULL;
|
walk_data.initialize_block_local_data = NULL;
|
walk_data.before_dom_children = nt_init_block;
|
walk_data.before_dom_children = nt_init_block;
|
walk_data.after_dom_children = nt_fini_block;
|
walk_data.after_dom_children = nt_fini_block;
|
walk_data.global_data = NULL;
|
walk_data.global_data = NULL;
|
walk_data.block_local_data_size = 0;
|
walk_data.block_local_data_size = 0;
|
|
|
init_walk_dominator_tree (&walk_data);
|
init_walk_dominator_tree (&walk_data);
|
walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
|
walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
|
fini_walk_dominator_tree (&walk_data);
|
fini_walk_dominator_tree (&walk_data);
|
htab_delete (seen_ssa_names);
|
htab_delete (seen_ssa_names);
|
|
|
return nontrap;
|
return nontrap;
|
}
|
}
|
|
|
/* Do the main work of conditional store replacement. We already know
|
/* Do the main work of conditional store replacement. We already know
|
that the recognized pattern looks like so:
|
that the recognized pattern looks like so:
|
|
|
split:
|
split:
|
if (cond) goto MIDDLE_BB; else goto JOIN_BB (edge E1)
|
if (cond) goto MIDDLE_BB; else goto JOIN_BB (edge E1)
|
MIDDLE_BB:
|
MIDDLE_BB:
|
something
|
something
|
fallthrough (edge E0)
|
fallthrough (edge E0)
|
JOIN_BB:
|
JOIN_BB:
|
some more
|
some more
|
|
|
We check that MIDDLE_BB contains only one store, that that store
|
We check that MIDDLE_BB contains only one store, that that store
|
doesn't trap (not via NOTRAP, but via checking if an access to the same
|
doesn't trap (not via NOTRAP, but via checking if an access to the same
|
memory location dominates us) and that the store has a "simple" RHS. */
|
memory location dominates us) and that the store has a "simple" RHS. */
|
|
|
static bool
|
static bool
|
cond_store_replacement (basic_block middle_bb, basic_block join_bb,
|
cond_store_replacement (basic_block middle_bb, basic_block join_bb,
|
edge e0, edge e1, struct pointer_set_t *nontrap)
|
edge e0, edge e1, struct pointer_set_t *nontrap)
|
{
|
{
|
gimple assign = last_and_only_stmt (middle_bb);
|
gimple assign = last_and_only_stmt (middle_bb);
|
tree lhs, rhs, name;
|
tree lhs, rhs, name;
|
gimple newphi, new_stmt;
|
gimple newphi, new_stmt;
|
gimple_stmt_iterator gsi;
|
gimple_stmt_iterator gsi;
|
source_location locus;
|
source_location locus;
|
enum tree_code code;
|
enum tree_code code;
|
|
|
/* Check if middle_bb contains of only one store. */
|
/* Check if middle_bb contains of only one store. */
|
if (!assign
|
if (!assign
|
|| gimple_code (assign) != GIMPLE_ASSIGN)
|
|| gimple_code (assign) != GIMPLE_ASSIGN)
|
return false;
|
return false;
|
|
|
locus = gimple_location (assign);
|
locus = gimple_location (assign);
|
lhs = gimple_assign_lhs (assign);
|
lhs = gimple_assign_lhs (assign);
|
rhs = gimple_assign_rhs1 (assign);
|
rhs = gimple_assign_rhs1 (assign);
|
if (!INDIRECT_REF_P (lhs))
|
if (!INDIRECT_REF_P (lhs))
|
return false;
|
return false;
|
|
|
/* RHS is either a single SSA_NAME or a constant. */
|
/* RHS is either a single SSA_NAME or a constant. */
|
code = gimple_assign_rhs_code (assign);
|
code = gimple_assign_rhs_code (assign);
|
if (get_gimple_rhs_class (code) != GIMPLE_SINGLE_RHS
|
if (get_gimple_rhs_class (code) != GIMPLE_SINGLE_RHS
|
|| (code != SSA_NAME && !is_gimple_min_invariant (rhs)))
|
|| (code != SSA_NAME && !is_gimple_min_invariant (rhs)))
|
return false;
|
return false;
|
/* Prove that we can move the store down. We could also check
|
/* Prove that we can move the store down. We could also check
|
TREE_THIS_NOTRAP here, but in that case we also could move stores,
|
TREE_THIS_NOTRAP here, but in that case we also could move stores,
|
whose value is not available readily, which we want to avoid. */
|
whose value is not available readily, which we want to avoid. */
|
if (!pointer_set_contains (nontrap, lhs))
|
if (!pointer_set_contains (nontrap, lhs))
|
return false;
|
return false;
|
|
|
/* Now we've checked the constraints, so do the transformation:
|
/* Now we've checked the constraints, so do the transformation:
|
1) Remove the single store. */
|
1) Remove the single store. */
|
mark_symbols_for_renaming (assign);
|
mark_symbols_for_renaming (assign);
|
gsi = gsi_for_stmt (assign);
|
gsi = gsi_for_stmt (assign);
|
gsi_remove (&gsi, true);
|
gsi_remove (&gsi, true);
|
|
|
/* 2) Create a temporary where we can store the old content
|
/* 2) Create a temporary where we can store the old content
|
of the memory touched by the store, if we need to. */
|
of the memory touched by the store, if we need to. */
|
if (!condstoretemp || TREE_TYPE (lhs) != TREE_TYPE (condstoretemp))
|
if (!condstoretemp || TREE_TYPE (lhs) != TREE_TYPE (condstoretemp))
|
{
|
{
|
condstoretemp = create_tmp_var (TREE_TYPE (lhs), "cstore");
|
condstoretemp = create_tmp_var (TREE_TYPE (lhs), "cstore");
|
get_var_ann (condstoretemp);
|
get_var_ann (condstoretemp);
|
if (TREE_CODE (TREE_TYPE (lhs)) == COMPLEX_TYPE
|
if (TREE_CODE (TREE_TYPE (lhs)) == COMPLEX_TYPE
|
|| TREE_CODE (TREE_TYPE (lhs)) == VECTOR_TYPE)
|
|| TREE_CODE (TREE_TYPE (lhs)) == VECTOR_TYPE)
|
DECL_GIMPLE_REG_P (condstoretemp) = 1;
|
DECL_GIMPLE_REG_P (condstoretemp) = 1;
|
}
|
}
|
add_referenced_var (condstoretemp);
|
add_referenced_var (condstoretemp);
|
|
|
/* 3) Insert a load from the memory of the store to the temporary
|
/* 3) Insert a load from the memory of the store to the temporary
|
on the edge which did not contain the store. */
|
on the edge which did not contain the store. */
|
lhs = unshare_expr (lhs);
|
lhs = unshare_expr (lhs);
|
new_stmt = gimple_build_assign (condstoretemp, lhs);
|
new_stmt = gimple_build_assign (condstoretemp, lhs);
|
name = make_ssa_name (condstoretemp, new_stmt);
|
name = make_ssa_name (condstoretemp, new_stmt);
|
gimple_assign_set_lhs (new_stmt, name);
|
gimple_assign_set_lhs (new_stmt, name);
|
gimple_set_location (new_stmt, locus);
|
gimple_set_location (new_stmt, locus);
|
mark_symbols_for_renaming (new_stmt);
|
mark_symbols_for_renaming (new_stmt);
|
gsi_insert_on_edge (e1, new_stmt);
|
gsi_insert_on_edge (e1, new_stmt);
|
|
|
/* 4) Create a PHI node at the join block, with one argument
|
/* 4) Create a PHI node at the join block, with one argument
|
holding the old RHS, and the other holding the temporary
|
holding the old RHS, and the other holding the temporary
|
where we stored the old memory contents. */
|
where we stored the old memory contents. */
|
newphi = create_phi_node (condstoretemp, join_bb);
|
newphi = create_phi_node (condstoretemp, join_bb);
|
add_phi_arg (newphi, rhs, e0, locus);
|
add_phi_arg (newphi, rhs, e0, locus);
|
add_phi_arg (newphi, name, e1, locus);
|
add_phi_arg (newphi, name, e1, locus);
|
|
|
lhs = unshare_expr (lhs);
|
lhs = unshare_expr (lhs);
|
new_stmt = gimple_build_assign (lhs, PHI_RESULT (newphi));
|
new_stmt = gimple_build_assign (lhs, PHI_RESULT (newphi));
|
mark_symbols_for_renaming (new_stmt);
|
mark_symbols_for_renaming (new_stmt);
|
|
|
/* 5) Insert that PHI node. */
|
/* 5) Insert that PHI node. */
|
gsi = gsi_after_labels (join_bb);
|
gsi = gsi_after_labels (join_bb);
|
if (gsi_end_p (gsi))
|
if (gsi_end_p (gsi))
|
{
|
{
|
gsi = gsi_last_bb (join_bb);
|
gsi = gsi_last_bb (join_bb);
|
gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT);
|
gsi_insert_after (&gsi, new_stmt, GSI_NEW_STMT);
|
}
|
}
|
else
|
else
|
gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT);
|
gsi_insert_before (&gsi, new_stmt, GSI_NEW_STMT);
|
|
|
return true;
|
return true;
|
}
|
}
|
|
|
/* Always do these optimizations if we have SSA
|
/* Always do these optimizations if we have SSA
|
trees to work on. */
|
trees to work on. */
|
static bool
|
static bool
|
gate_phiopt (void)
|
gate_phiopt (void)
|
{
|
{
|
return 1;
|
return 1;
|
}
|
}
|
|
|
struct gimple_opt_pass pass_phiopt =
|
struct gimple_opt_pass pass_phiopt =
|
{
|
{
|
{
|
{
|
GIMPLE_PASS,
|
GIMPLE_PASS,
|
"phiopt", /* name */
|
"phiopt", /* name */
|
gate_phiopt, /* gate */
|
gate_phiopt, /* gate */
|
tree_ssa_phiopt, /* execute */
|
tree_ssa_phiopt, /* execute */
|
NULL, /* sub */
|
NULL, /* sub */
|
NULL, /* next */
|
NULL, /* next */
|
0, /* static_pass_number */
|
0, /* static_pass_number */
|
TV_TREE_PHIOPT, /* tv_id */
|
TV_TREE_PHIOPT, /* tv_id */
|
PROP_cfg | PROP_ssa, /* properties_required */
|
PROP_cfg | PROP_ssa, /* properties_required */
|
0, /* properties_provided */
|
0, /* properties_provided */
|
0, /* properties_destroyed */
|
0, /* properties_destroyed */
|
0, /* todo_flags_start */
|
0, /* todo_flags_start */
|
TODO_dump_func
|
TODO_dump_func
|
| TODO_ggc_collect
|
| TODO_ggc_collect
|
| TODO_verify_ssa
|
| TODO_verify_ssa
|
| TODO_verify_flow
|
| TODO_verify_flow
|
| TODO_verify_stmts /* todo_flags_finish */
|
| TODO_verify_stmts /* todo_flags_finish */
|
}
|
}
|
};
|
};
|
|
|
static bool
|
static bool
|
gate_cselim (void)
|
gate_cselim (void)
|
{
|
{
|
return flag_tree_cselim;
|
return flag_tree_cselim;
|
}
|
}
|
|
|
struct gimple_opt_pass pass_cselim =
|
struct gimple_opt_pass pass_cselim =
|
{
|
{
|
{
|
{
|
GIMPLE_PASS,
|
GIMPLE_PASS,
|
"cselim", /* name */
|
"cselim", /* name */
|
gate_cselim, /* gate */
|
gate_cselim, /* gate */
|
tree_ssa_cs_elim, /* execute */
|
tree_ssa_cs_elim, /* execute */
|
NULL, /* sub */
|
NULL, /* sub */
|
NULL, /* next */
|
NULL, /* next */
|
0, /* static_pass_number */
|
0, /* static_pass_number */
|
TV_TREE_PHIOPT, /* tv_id */
|
TV_TREE_PHIOPT, /* tv_id */
|
PROP_cfg | PROP_ssa, /* properties_required */
|
PROP_cfg | PROP_ssa, /* properties_required */
|
0, /* properties_provided */
|
0, /* properties_provided */
|
0, /* properties_destroyed */
|
0, /* properties_destroyed */
|
0, /* todo_flags_start */
|
0, /* todo_flags_start */
|
TODO_dump_func
|
TODO_dump_func
|
| TODO_ggc_collect
|
| TODO_ggc_collect
|
| TODO_verify_ssa
|
| TODO_verify_ssa
|
| TODO_verify_flow
|
| TODO_verify_flow
|
| TODO_verify_stmts /* todo_flags_finish */
|
| TODO_verify_stmts /* todo_flags_finish */
|
}
|
}
|
};
|
};
|
|
|
