/* Convert a program in SSA form into Normal form.
- Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+ Copyright (C) 2004-2019 Free Software Foundation, Inc.
Contributed by Andrew Macleod <amacleod@redhat.com>
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
+#include "backend.h"
+#include "rtl.h"
#include "tree.h"
-#include "ggc.h"
-#include "basic-block.h"
-#include "diagnostic.h"
-#include "bitmap.h"
-#include "tree-flow.h"
-#include "timevar.h"
-#include "tree-dump.h"
-#include "tree-pass.h"
-#include "toplev.h"
+#include "gimple.h"
+#include "cfghooks.h"
+#include "ssa.h"
+#include "tree-ssa.h"
+#include "memmodel.h"
+#include "emit-rtl.h"
+#include "gimple-pretty-print.h"
+#include "diagnostic-core.h"
+#include "tree-dfa.h"
+#include "stor-layout.h"
+#include "cfgrtl.h"
+#include "cfganal.h"
+#include "tree-eh.h"
+#include "gimple-iterator.h"
+#include "tree-cfg.h"
+#include "dumpfile.h"
+#include "tree-ssa-live.h"
+#include "tree-ssa-ter.h"
+#include "tree-ssa-coalesce.h"
+#include "tree-outof-ssa.h"
+#include "dojump.h"
+
+/* FIXME: A lot of code here deals with expanding to RTL. All that code
+ should be in cfgexpand.c. */
+#include "explow.h"
#include "expr.h"
-#include "ssaexpand.h"
+
+/* Return TRUE if expression STMT is suitable for replacement. */
+
+bool
+ssa_is_replaceable_p (gimple *stmt)
+{
+ use_operand_p use_p;
+ tree def;
+ gimple *use_stmt;
+
+ /* Only consider modify stmts. */
+ if (!is_gimple_assign (stmt))
+ return false;
+
+ /* If the statement may throw an exception, it cannot be replaced. */
+ if (stmt_could_throw_p (cfun, stmt))
+ return false;
+
+ /* Punt if there is more than 1 def. */
+ def = SINGLE_SSA_TREE_OPERAND (stmt, SSA_OP_DEF);
+ if (!def)
+ return false;
+
+ /* Only consider definitions which have a single use. */
+ if (!single_imm_use (def, &use_p, &use_stmt))
+ return false;
+
+ /* Used in this block, but at the TOP of the block, not the end. */
+ if (gimple_code (use_stmt) == GIMPLE_PHI)
+ return false;
+
+ /* There must be no VDEFs. */
+ if (gimple_vdef (stmt))
+ return false;
+
+ /* Float expressions must go through memory if float-store is on. */
+ if (flag_float_store
+ && FLOAT_TYPE_P (gimple_expr_type (stmt)))
+ return false;
+
+ /* An assignment with a register variable on the RHS is not
+ replaceable. */
+ if (gimple_assign_rhs_code (stmt) == VAR_DECL
+ && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt)))
+ return false;
+
+ /* No function calls can be replaced. */
+ if (is_gimple_call (stmt))
+ return false;
+
+ /* Leave any stmt with volatile operands alone as well. */
+ if (gimple_has_volatile_ops (stmt))
+ return false;
+
+ return true;
+}
/* Used to hold all the components required to do SSA PHI elimination.
edges represented as pairs of nodes.
The predecessor and successor list: Nodes are entered in pairs, where
- [0] ->PRED, [1]->SUCC. All the even indexes in the array represent
- predecessors, all the odd elements are successors.
-
+ [0] ->PRED, [1]->SUCC. All the even indexes in the array represent
+ predecessors, all the odd elements are successors.
+
Rationale:
- When implemented as bitmaps, very large programs SSA->Normal times were
+ When implemented as bitmaps, very large programs SSA->Normal times were
being dominated by clearing the interference graph.
- Typically this list of edges is extremely small since it only includes
- PHI results and uses from a single edge which have not coalesced with
+ Typically this list of edges is extremely small since it only includes
+ PHI results and uses from a single edge which have not coalesced with
each other. This means that no virtual PHI nodes are included, and
empirical evidence suggests that the number of edges rarely exceed
3, and in a bootstrap of GCC, the maximum size encountered was 7.
This also limits the number of possible nodes that are involved to
rarely more than 6, and in the bootstrap of gcc, the maximum number
of nodes encountered was 12. */
-
-typedef struct _elim_graph {
+
+struct elim_graph
+{
+ elim_graph (var_map map);
+
/* Size of the elimination vectors. */
int size;
/* List of nodes in the elimination graph. */
- VEC(int,heap) *nodes;
+ auto_vec<int> nodes;
/* The predecessor and successor edge list. */
- VEC(int,heap) *edge_list;
+ auto_vec<int> edge_list;
+
+ /* Source locus on each edge */
+ auto_vec<location_t> edge_locus;
/* Visited vector. */
- sbitmap visited;
+ auto_sbitmap visited;
/* Stack for visited nodes. */
- VEC(int,heap) *stack;
-
+ auto_vec<int> stack;
+
/* The variable partition map. */
var_map map;
edge e;
/* List of constant copies to emit. These are pushed on in pairs. */
- VEC(int,heap) *const_dests;
- VEC(tree,heap) *const_copies;
-} *elim_graph;
+ auto_vec<int> const_dests;
+ auto_vec<tree> const_copies;
+
+ /* Source locations for any constant copies. */
+ auto_vec<location_t> copy_locus;
+};
/* For an edge E find out a good source location to associate with
{
if (e->goto_locus)
{
- set_curr_insn_source_location (e->goto_locus);
- set_curr_insn_block (e->goto_block);
+ set_curr_insn_location (e->goto_locus);
}
else
{
{
for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi))
{
- gimple stmt = gsi_stmt (gsi);
+ gimple *stmt = gsi_stmt (gsi);
+ if (is_gimple_debug (stmt))
+ continue;
if (gimple_has_location (stmt) || gimple_block (stmt))
{
- set_curr_insn_source_location (gimple_location (stmt));
- set_curr_insn_block (gimple_block (stmt));
+ set_curr_insn_location (gimple_location (stmt));
return;
}
}
}
}
-/* Emit insns to copy SRC into DEST converting SRC if necessary. */
+/* Emit insns to copy SRC into DEST converting SRC if necessary. As
+ SRC/DEST might be BLKmode memory locations SIZEEXP is a tree from
+ which we deduce the size to copy in that case. */
-static inline rtx
-emit_partition_copy (rtx dest, rtx src, int unsignedsrcp)
+static inline rtx_insn *
+emit_partition_copy (rtx dest, rtx src, int unsignedsrcp, tree sizeexp)
{
- rtx seq;
-
start_sequence ();
if (GET_MODE (src) != VOIDmode && GET_MODE (src) != GET_MODE (dest))
src = convert_to_mode (GET_MODE (dest), src, unsignedsrcp);
- emit_move_insn (dest, src);
+ if (GET_MODE (src) == BLKmode)
+ {
+ gcc_assert (GET_MODE (dest) == BLKmode);
+ emit_block_move (dest, src, expr_size (sizeexp), BLOCK_OP_NORMAL);
+ }
+ else
+ emit_move_insn (dest, src);
+ do_pending_stack_adjust ();
- seq = get_insns ();
+ rtx_insn *seq = get_insns ();
end_sequence ();
return seq;
/* Insert a copy instruction from partition SRC to DEST onto edge E. */
static void
-insert_partition_copy_on_edge (edge e, int dest, int src)
+insert_partition_copy_on_edge (edge e, int dest, int src, location_t locus)
{
- rtx seq;
+ tree var;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file,
- "Inserting a partition copy on edge BB%d->BB%d :"
+ "Inserting a partition copy on edge BB%d->BB%d : "
"PART.%d = PART.%d",
e->src->index,
e->dest->index, dest, src);
gcc_assert (SA.partition_to_pseudo[src]);
set_location_for_edge (e);
+ /* If a locus is provided, override the default. */
+ if (locus)
+ set_curr_insn_location (locus);
- seq = emit_partition_copy (SA.partition_to_pseudo[dest],
- SA.partition_to_pseudo[src],
- TYPE_UNSIGNED (TREE_TYPE (
- partition_to_var (SA.map, src))));
+ var = partition_to_var (SA.map, src);
+ rtx_insn *seq = emit_partition_copy (copy_rtx (SA.partition_to_pseudo[dest]),
+ copy_rtx (SA.partition_to_pseudo[src]),
+ TYPE_UNSIGNED (TREE_TYPE (var)),
+ var);
insert_insn_on_edge (seq, e);
}
onto edge E. */
static void
-insert_value_copy_on_edge (edge e, int dest, tree src)
+insert_value_copy_on_edge (edge e, int dest, tree src, location_t locus)
{
- rtx seq, x;
- enum machine_mode mode;
+ rtx dest_rtx, seq, x;
+ machine_mode dest_mode, src_mode;
+ int unsignedp;
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file,
fprintf (dump_file, "\n");
}
- gcc_assert (SA.partition_to_pseudo[dest]);
+ dest_rtx = copy_rtx (SA.partition_to_pseudo[dest]);
+ gcc_assert (dest_rtx);
set_location_for_edge (e);
+ /* If a locus is provided, override the default. */
+ if (locus)
+ set_curr_insn_location (locus);
start_sequence ();
- mode = GET_MODE (SA.partition_to_pseudo[dest]);
- x = expand_expr (src, SA.partition_to_pseudo[dest], mode, EXPAND_NORMAL);
- if (GET_MODE (x) != VOIDmode && GET_MODE (x) != mode)
- x = convert_to_mode (mode, x, TYPE_UNSIGNED (TREE_TYPE (src)));
- if (CONSTANT_P (x) && GET_MODE (x) == VOIDmode
- && mode != TYPE_MODE (TREE_TYPE (src)))
- x = convert_modes (mode, TYPE_MODE (TREE_TYPE (src)),
- x, TYPE_UNSIGNED (TREE_TYPE (src)));
- if (x != SA.partition_to_pseudo[dest])
- emit_move_insn (SA.partition_to_pseudo[dest], x);
+
+ tree name = partition_to_var (SA.map, dest);
+ src_mode = TYPE_MODE (TREE_TYPE (src));
+ dest_mode = GET_MODE (dest_rtx);
+ gcc_assert (src_mode == TYPE_MODE (TREE_TYPE (name)));
+ gcc_assert (!REG_P (dest_rtx)
+ || dest_mode == promote_ssa_mode (name, &unsignedp));
+
+ if (src_mode != dest_mode)
+ {
+ x = expand_expr (src, NULL, src_mode, EXPAND_NORMAL);
+ x = convert_modes (dest_mode, src_mode, x, unsignedp);
+ }
+ else if (src_mode == BLKmode)
+ {
+ x = dest_rtx;
+ store_expr (src, x, 0, false, false);
+ }
+ else
+ x = expand_expr (src, dest_rtx, dest_mode, EXPAND_NORMAL);
+
+ if (x != dest_rtx)
+ emit_move_insn (dest_rtx, x);
+ do_pending_stack_adjust ();
+
seq = get_insns ();
end_sequence ();
onto edge E. */
static void
-insert_rtx_to_part_on_edge (edge e, int dest, rtx src, int unsignedsrcp)
+insert_rtx_to_part_on_edge (edge e, int dest, rtx src, int unsignedsrcp,
+ location_t locus)
{
- rtx seq;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file,
}
gcc_assert (SA.partition_to_pseudo[dest]);
- set_location_for_edge (e);
- seq = emit_partition_copy (SA.partition_to_pseudo[dest],
- src,
- unsignedsrcp);
+ set_location_for_edge (e);
+ /* If a locus is provided, override the default. */
+ if (locus)
+ set_curr_insn_location (locus);
+
+ /* We give the destination as sizeexp in case src/dest are BLKmode
+ mems. Usually we give the source. As we result from SSA names
+ the left and right size should be the same (and no WITH_SIZE_EXPR
+ involved), so it doesn't matter. */
+ rtx_insn *seq = emit_partition_copy (copy_rtx (SA.partition_to_pseudo[dest]),
+ src, unsignedsrcp,
+ partition_to_var (SA.map, dest));
insert_insn_on_edge (seq, e);
}
onto edge E. */
static void
-insert_part_to_rtx_on_edge (edge e, rtx dest, int src)
+insert_part_to_rtx_on_edge (edge e, rtx dest, int src, location_t locus)
{
- rtx seq;
+ tree var;
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file,
}
gcc_assert (SA.partition_to_pseudo[src]);
+
set_location_for_edge (e);
+ /* If a locus is provided, override the default. */
+ if (locus)
+ set_curr_insn_location (locus);
- seq = emit_partition_copy (dest,
- SA.partition_to_pseudo[src],
- TYPE_UNSIGNED (TREE_TYPE (
- partition_to_var (SA.map, src))));
+ var = partition_to_var (SA.map, src);
+ rtx_insn *seq = emit_partition_copy (dest,
+ copy_rtx (SA.partition_to_pseudo[src]),
+ TYPE_UNSIGNED (TREE_TYPE (var)),
+ var);
insert_insn_on_edge (seq, e);
}
-/* Create an elimination graph with SIZE nodes and associated data
- structures. */
+/* Create an elimination graph for map. */
-static elim_graph
-new_elim_graph (int size)
+elim_graph::elim_graph (var_map map) :
+ nodes (30), edge_list (20), edge_locus (10), visited (map->num_partitions),
+ stack (30), map (map), const_dests (20), const_copies (20), copy_locus (10)
{
- elim_graph g = (elim_graph) xmalloc (sizeof (struct _elim_graph));
-
- g->nodes = VEC_alloc (int, heap, 30);
- g->const_dests = VEC_alloc (int, heap, 20);
- g->const_copies = VEC_alloc (tree, heap, 20);
- g->edge_list = VEC_alloc (int, heap, 20);
- g->stack = VEC_alloc (int, heap, 30);
-
- g->visited = sbitmap_alloc (size);
-
- return g;
}
/* Empty elimination graph G. */
static inline void
-clear_elim_graph (elim_graph g)
+clear_elim_graph (elim_graph *g)
{
- VEC_truncate (int, g->nodes, 0);
- VEC_truncate (int, g->edge_list, 0);
-}
-
-
-/* Delete elimination graph G. */
-
-static inline void
-delete_elim_graph (elim_graph g)
-{
- sbitmap_free (g->visited);
- VEC_free (int, heap, g->stack);
- VEC_free (int, heap, g->edge_list);
- VEC_free (tree, heap, g->const_copies);
- VEC_free (int, heap, g->const_dests);
- VEC_free (int, heap, g->nodes);
- free (g);
+ g->nodes.truncate (0);
+ g->edge_list.truncate (0);
+ g->edge_locus.truncate (0);
}
/* Return the number of nodes in graph G. */
static inline int
-elim_graph_size (elim_graph g)
+elim_graph_size (elim_graph *g)
{
- return VEC_length (int, g->nodes);
+ return g->nodes.length ();
}
/* Add NODE to graph G, if it doesn't exist already. */
-static inline void
-elim_graph_add_node (elim_graph g, int node)
+static inline void
+elim_graph_add_node (elim_graph *g, int node)
{
int x;
int t;
- for (x = 0; VEC_iterate (int, g->nodes, x, t); x++)
+ FOR_EACH_VEC_ELT (g->nodes, x, t)
if (t == node)
return;
- VEC_safe_push (int, heap, g->nodes, node);
+ g->nodes.safe_push (node);
}
/* Add the edge PRED->SUCC to graph G. */
static inline void
-elim_graph_add_edge (elim_graph g, int pred, int succ)
+elim_graph_add_edge (elim_graph *g, int pred, int succ, location_t locus)
{
- VEC_safe_push (int, heap, g->edge_list, pred);
- VEC_safe_push (int, heap, g->edge_list, succ);
+ g->edge_list.safe_push (pred);
+ g->edge_list.safe_push (succ);
+ g->edge_locus.safe_push (locus);
}
return the successor node. -1 is returned if there is no such edge. */
static inline int
-elim_graph_remove_succ_edge (elim_graph g, int node)
+elim_graph_remove_succ_edge (elim_graph *g, int node, location_t *locus)
{
int y;
unsigned x;
- for (x = 0; x < VEC_length (int, g->edge_list); x += 2)
- if (VEC_index (int, g->edge_list, x) == node)
+ for (x = 0; x < g->edge_list.length (); x += 2)
+ if (g->edge_list[x] == node)
{
- VEC_replace (int, g->edge_list, x, -1);
- y = VEC_index (int, g->edge_list, x + 1);
- VEC_replace (int, g->edge_list, x + 1, -1);
+ g->edge_list[x] = -1;
+ y = g->edge_list[x + 1];
+ g->edge_list[x + 1] = -1;
+ *locus = g->edge_locus[x / 2];
+ g->edge_locus[x / 2] = UNKNOWN_LOCATION;
return y;
}
+ *locus = UNKNOWN_LOCATION;
return -1;
}
edge list. VAR will hold the partition number found. CODE is the
code fragment executed for every node found. */
-#define FOR_EACH_ELIM_GRAPH_SUCC(GRAPH, NODE, VAR, CODE) \
+#define FOR_EACH_ELIM_GRAPH_SUCC(GRAPH, NODE, VAR, LOCUS, CODE) \
do { \
unsigned x_; \
int y_; \
- for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \
+ for (x_ = 0; x_ < (GRAPH)->edge_list.length (); x_ += 2) \
{ \
- y_ = VEC_index (int, (GRAPH)->edge_list, x_); \
+ y_ = (GRAPH)->edge_list[x_]; \
if (y_ != (NODE)) \
continue; \
- (VAR) = VEC_index (int, (GRAPH)->edge_list, x_ + 1); \
+ (void) ((VAR) = (GRAPH)->edge_list[x_ + 1]); \
+ (void) ((LOCUS) = (GRAPH)->edge_locus[x_ / 2]); \
CODE; \
} \
} while (0)
GRAPH. VAR will hold the partition number found. CODE is the
code fragment executed for every node found. */
-#define FOR_EACH_ELIM_GRAPH_PRED(GRAPH, NODE, VAR, CODE) \
+#define FOR_EACH_ELIM_GRAPH_PRED(GRAPH, NODE, VAR, LOCUS, CODE) \
do { \
unsigned x_; \
int y_; \
- for (x_ = 0; x_ < VEC_length (int, (GRAPH)->edge_list); x_ += 2) \
+ for (x_ = 0; x_ < (GRAPH)->edge_list.length (); x_ += 2) \
{ \
- y_ = VEC_index (int, (GRAPH)->edge_list, x_ + 1); \
+ y_ = (GRAPH)->edge_list[x_ + 1]; \
if (y_ != (NODE)) \
continue; \
- (VAR) = VEC_index (int, (GRAPH)->edge_list, x_); \
+ (void) ((VAR) = (GRAPH)->edge_list[x_]); \
+ (void) ((LOCUS) = (GRAPH)->edge_locus[x_ / 2]); \
CODE; \
} \
} while (0)
/* Add T to elimination graph G. */
static inline void
-eliminate_name (elim_graph g, int T)
+eliminate_name (elim_graph *g, int T)
{
elim_graph_add_node (g, T);
}
+/* Return true if this phi argument T should have a copy queued when using
+ var_map MAP. PHI nodes should contain only ssa_names and invariants. A
+ test for ssa_name is definitely simpler, but don't let invalid contents
+ slip through in the meantime. */
+
+static inline bool
+queue_phi_copy_p (var_map map, tree t)
+{
+ if (TREE_CODE (t) == SSA_NAME)
+ {
+ if (var_to_partition (map, t) == NO_PARTITION)
+ return true;
+ return false;
+ }
+ gcc_checking_assert (is_gimple_min_invariant (t));
+ return true;
+}
/* Build elimination graph G for basic block BB on incoming PHI edge
G->e. */
static void
-eliminate_build (elim_graph g)
+eliminate_build (elim_graph *g)
{
tree Ti;
int p0, pi;
- gimple_stmt_iterator gsi;
+ gphi_iterator gsi;
clear_elim_graph (g);
-
+
for (gsi = gsi_start_phis (g->e->dest); !gsi_end_p (gsi); gsi_next (&gsi))
{
- gimple phi = gsi_stmt (gsi);
+ gphi *phi = gsi.phi ();
+ location_t locus;
p0 = var_to_partition (g->map, gimple_phi_result (phi));
/* Ignore results which are not in partitions. */
continue;
Ti = PHI_ARG_DEF (phi, g->e->dest_idx);
+ locus = gimple_phi_arg_location_from_edge (phi, g->e);
/* If this argument is a constant, or a SSA_NAME which is being
left in SSA form, just queue a copy to be emitted on this
edge. */
- if (!phi_ssa_name_p (Ti)
- || (TREE_CODE (Ti) == SSA_NAME
- && var_to_partition (g->map, Ti) == NO_PARTITION))
+ if (queue_phi_copy_p (g->map, Ti))
{
/* Save constant copies until all other copies have been emitted
on this edge. */
- VEC_safe_push (int, heap, g->const_dests, p0);
- VEC_safe_push (tree, heap, g->const_copies, Ti);
+ g->const_dests.safe_push (p0);
+ g->const_copies.safe_push (Ti);
+ g->copy_locus.safe_push (locus);
}
else
{
{
eliminate_name (g, p0);
eliminate_name (g, pi);
- elim_graph_add_edge (g, p0, pi);
+ elim_graph_add_edge (g, p0, pi, locus);
}
}
}
/* Push successors of T onto the elimination stack for G. */
-static void
-elim_forward (elim_graph g, int T)
+static void
+elim_forward (elim_graph *g, int T)
{
int S;
- SET_BIT (g->visited, T);
- FOR_EACH_ELIM_GRAPH_SUCC (g, T, S,
+ location_t locus;
+
+ bitmap_set_bit (g->visited, T);
+ FOR_EACH_ELIM_GRAPH_SUCC (g, T, S, locus,
{
- if (!TEST_BIT (g->visited, S))
+ if (!bitmap_bit_p (g->visited, S))
elim_forward (g, S);
});
- VEC_safe_push (int, heap, g->stack, T);
+ g->stack.safe_push (T);
}
/* Return 1 if there unvisited predecessors of T in graph G. */
static int
-elim_unvisited_predecessor (elim_graph g, int T)
+elim_unvisited_predecessor (elim_graph *g, int T)
{
int P;
- FOR_EACH_ELIM_GRAPH_PRED (g, T, P,
+ location_t locus;
+
+ FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
{
- if (!TEST_BIT (g->visited, P))
+ if (!bitmap_bit_p (g->visited, P))
return 1;
});
return 0;
/* Process predecessors first, and insert a copy. */
static void
-elim_backward (elim_graph g, int T)
+elim_backward (elim_graph *g, int T)
{
int P;
- SET_BIT (g->visited, T);
- FOR_EACH_ELIM_GRAPH_PRED (g, T, P,
+ location_t locus;
+
+ bitmap_set_bit (g->visited, T);
+ FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
{
- if (!TEST_BIT (g->visited, P))
+ if (!bitmap_bit_p (g->visited, P))
{
elim_backward (g, P);
- insert_partition_copy_on_edge (g->e, P, T);
+ insert_partition_copy_on_edge (g->e, P, T, locus);
}
});
}
static rtx
get_temp_reg (tree name)
{
- tree var = TREE_CODE (name) == SSA_NAME ? SSA_NAME_VAR (name) : name;
- tree type = TREE_TYPE (var);
- int unsignedp = TYPE_UNSIGNED (type);
- enum machine_mode reg_mode
- = promote_mode (type, DECL_MODE (var), &unsignedp, 0);
+ tree type = TREE_TYPE (name);
+ int unsignedp;
+ machine_mode reg_mode = promote_ssa_mode (name, &unsignedp);
+ if (reg_mode == BLKmode)
+ return assign_temp (type, 0, 0);
rtx x = gen_reg_rtx (reg_mode);
if (POINTER_TYPE_P (type))
- mark_reg_pointer (x, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (var))));
+ mark_reg_pointer (x, TYPE_ALIGN (TREE_TYPE (type)));
return x;
}
-/* Insert required copies for T in graph G. Check for a strongly connected
+/* Insert required copies for T in graph G. Check for a strongly connected
region, and create a temporary to break the cycle if one is found. */
-static void
-elim_create (elim_graph g, int T)
+static void
+elim_create (elim_graph *g, int T)
{
int P, S;
+ location_t locus;
if (elim_unvisited_predecessor (g, T))
{
rtx U = get_temp_reg (var);
int unsignedsrcp = TYPE_UNSIGNED (TREE_TYPE (var));
- insert_part_to_rtx_on_edge (g->e, U, T);
- FOR_EACH_ELIM_GRAPH_PRED (g, T, P,
+ insert_part_to_rtx_on_edge (g->e, U, T, UNKNOWN_LOCATION);
+ FOR_EACH_ELIM_GRAPH_PRED (g, T, P, locus,
{
- if (!TEST_BIT (g->visited, P))
+ if (!bitmap_bit_p (g->visited, P))
{
elim_backward (g, P);
- insert_rtx_to_part_on_edge (g->e, P, U, unsignedsrcp);
+ insert_rtx_to_part_on_edge (g->e, P, U, unsignedsrcp, locus);
}
});
}
else
{
- S = elim_graph_remove_succ_edge (g, T);
+ S = elim_graph_remove_succ_edge (g, T, &locus);
if (S != -1)
{
- SET_BIT (g->visited, T);
- insert_partition_copy_on_edge (g->e, T, S);
+ bitmap_set_bit (g->visited, T);
+ insert_partition_copy_on_edge (g->e, T, S, locus);
}
}
}
/* Eliminate all the phi nodes on edge E in graph G. */
static void
-eliminate_phi (edge e, elim_graph g)
+eliminate_phi (edge e, elim_graph *g)
{
int x;
- gcc_assert (VEC_length (tree, g->const_copies) == 0);
+ gcc_assert (g->const_copies.length () == 0);
+ gcc_assert (g->copy_locus.length () == 0);
/* Abnormal edges already have everything coalesced. */
if (e->flags & EDGE_ABNORMAL)
{
int part;
- sbitmap_zero (g->visited);
- VEC_truncate (int, g->stack, 0);
+ bitmap_clear (g->visited);
+ g->stack.truncate (0);
- for (x = 0; VEC_iterate (int, g->nodes, x, part); x++)
+ FOR_EACH_VEC_ELT (g->nodes, x, part)
{
- if (!TEST_BIT (g->visited, part))
+ if (!bitmap_bit_p (g->visited, part))
elim_forward (g, part);
}
-
- sbitmap_zero (g->visited);
- while (VEC_length (int, g->stack) > 0)
+
+ bitmap_clear (g->visited);
+ while (g->stack.length () > 0)
{
- x = VEC_pop (int, g->stack);
- if (!TEST_BIT (g->visited, x))
+ x = g->stack.pop ();
+ if (!bitmap_bit_p (g->visited, x))
elim_create (g, x);
}
}
/* If there are any pending constant copies, issue them now. */
- while (VEC_length (tree, g->const_copies) > 0)
+ while (g->const_copies.length () > 0)
{
int dest;
tree src;
- src = VEC_pop (tree, g->const_copies);
- dest = VEC_pop (int, g->const_dests);
- insert_value_copy_on_edge (e, dest, src);
+ location_t locus;
+
+ src = g->const_copies.pop ();
+ dest = g->const_dests.pop ();
+ locus = g->copy_locus.pop ();
+ insert_value_copy_on_edge (e, dest, src, locus);
}
}
-/* Remove each argument from PHI. If an arg was the last use of an SSA_NAME,
+/* Remove each argument from PHI. If an arg was the last use of an SSA_NAME,
check to see if this allows another PHI node to be removed. */
static void
-remove_gimple_phi_args (gimple phi)
+remove_gimple_phi_args (gphi *phi)
{
use_operand_p arg_p;
ssa_op_iter iter;
SET_USE (arg_p, NULL_TREE);
if (has_zero_uses (arg))
{
- gimple stmt;
+ gimple *stmt;
gimple_stmt_iterator gsi;
stmt = SSA_NAME_DEF_STMT (arg);
/* Also remove the def if it is a PHI node. */
if (gimple_code (stmt) == GIMPLE_PHI)
{
- remove_gimple_phi_args (stmt);
+ remove_gimple_phi_args (as_a <gphi *> (stmt));
gsi = gsi_for_stmt (stmt);
remove_phi_node (&gsi, true);
}
eliminate_useless_phis (void)
{
basic_block bb;
- gimple_stmt_iterator gsi;
+ gphi_iterator gsi;
tree result;
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); )
{
- gimple phi = gsi_stmt (gsi);
+ gphi *phi = gsi.phi ();
result = gimple_phi_result (phi);
- if (!is_gimple_reg (SSA_NAME_VAR (result)))
- {
-#ifdef ENABLE_CHECKING
- size_t i;
- /* There should be no arguments which are not virtual, or the
- results will be incorrect. */
- for (i = 0; i < gimple_phi_num_args (phi); i++)
- {
- tree arg = PHI_ARG_DEF (phi, i);
- if (TREE_CODE (arg) == SSA_NAME
- && is_gimple_reg (SSA_NAME_VAR (arg)))
- {
- fprintf (stderr, "Argument of PHI is not virtual (");
- print_generic_expr (stderr, arg, TDF_SLIM);
- fprintf (stderr, "), but the result is :");
- print_gimple_stmt (stderr, phi, 0, TDF_SLIM);
- internal_error ("SSA corruption");
- }
- }
-#endif
- remove_phi_node (&gsi, true);
- }
+ if (virtual_operand_p (result))
+ remove_phi_node (&gsi, true);
else
{
/* Also remove real PHIs with no uses. */
/* This function will rewrite the current program using the variable mapping
- found in MAP. If the replacement vector VALUES is provided, any
- occurrences of partitions with non-null entries in the vector will be
- replaced with the expression in the vector instead of its mapped
+ found in MAP. If the replacement vector VALUES is provided, any
+ occurrences of partitions with non-null entries in the vector will be
+ replaced with the expression in the vector instead of its mapped
variable. */
static void
-rewrite_trees (var_map map ATTRIBUTE_UNUSED)
+rewrite_trees (var_map map)
{
-#ifdef ENABLE_CHECKING
+ if (!flag_checking)
+ return;
+
basic_block bb;
/* Search for PHIs where the destination has no partition, but one
or more arguments has a partition. This should not happen and can
create incorrect code. */
- FOR_EACH_BB (bb)
+ FOR_EACH_BB_FN (bb, cfun)
{
- gimple_stmt_iterator gsi;
+ gphi_iterator gsi;
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- gimple phi = gsi_stmt (gsi);
+ gphi *phi = gsi.phi ();
tree T0 = var_to_partition_to_var (map, gimple_phi_result (phi));
if (T0 == NULL_TREE)
{
}
}
}
-#endif
+}
+
+/* Create a default def for VAR. */
+
+static void
+create_default_def (tree var, void *arg ATTRIBUTE_UNUSED)
+{
+ if (!is_gimple_reg (var))
+ return;
+
+ tree ssa = get_or_create_ssa_default_def (cfun, var);
+ gcc_assert (ssa);
+}
+
+/* Call CALLBACK for all PARM_DECLs and RESULT_DECLs for which
+ assign_parms may ask for a default partition. */
+
+static void
+for_all_parms (void (*callback)(tree var, void *arg), void *arg)
+{
+ for (tree var = DECL_ARGUMENTS (current_function_decl); var;
+ var = DECL_CHAIN (var))
+ callback (var, arg);
+ if (!VOID_TYPE_P (TREE_TYPE (DECL_RESULT (current_function_decl))))
+ callback (DECL_RESULT (current_function_decl), arg);
+ if (cfun->static_chain_decl)
+ callback (cfun->static_chain_decl, arg);
+}
+
+/* We need to pass two arguments to set_parm_default_def_partition,
+ but for_all_parms only supports one. Use a pair. */
+
+typedef std::pair<var_map, bitmap> parm_default_def_partition_arg;
+
+/* Set in ARG's PARTS bitmap the bit corresponding to the partition in
+ ARG's MAP containing VAR's default def. */
+
+static void
+set_parm_default_def_partition (tree var, void *arg_)
+{
+ parm_default_def_partition_arg *arg = (parm_default_def_partition_arg *)arg_;
+ var_map map = arg->first;
+ bitmap parts = arg->second;
+
+ if (!is_gimple_reg (var))
+ return;
+
+ tree ssa = ssa_default_def (cfun, var);
+ gcc_assert (ssa);
+
+ int version = var_to_partition (map, ssa);
+ gcc_assert (version != NO_PARTITION);
+
+ bool changed = bitmap_set_bit (parts, version);
+ gcc_assert (changed);
+}
+
+/* Allocate and return a bitmap that has a bit set for each partition
+ that contains a default def for a parameter. */
+
+static bitmap
+get_parm_default_def_partitions (var_map map)
+{
+ bitmap parm_default_def_parts = BITMAP_ALLOC (NULL);
+
+ parm_default_def_partition_arg
+ arg = std::make_pair (map, parm_default_def_parts);
+
+ for_all_parms (set_parm_default_def_partition, &arg);
+
+ return parm_default_def_parts;
+}
+
+/* Allocate and return a bitmap that has a bit set for each partition
+ that contains an undefined value. */
+
+static bitmap
+get_undefined_value_partitions (var_map map)
+{
+ bitmap undefined_value_parts = BITMAP_ALLOC (NULL);
+
+ for (unsigned int i = 1; i < num_ssa_names; i++)
+ {
+ tree var = ssa_name (i);
+ if (var
+ && !virtual_operand_p (var)
+ && !has_zero_uses (var)
+ && ssa_undefined_value_p (var))
+ {
+ const int p = var_to_partition (map, var);
+ if (p != NO_PARTITION)
+ bitmap_set_bit (undefined_value_parts, p);
+ }
+ }
+
+ return undefined_value_parts;
}
/* Given the out-of-ssa info object SA (with prepared partitions)
expand_phi_nodes (struct ssaexpand *sa)
{
basic_block bb;
- elim_graph g = new_elim_graph (sa->map->num_partitions);
- g->map = sa->map;
+ elim_graph g (sa->map);
- FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb,
+ EXIT_BLOCK_PTR_FOR_FN (cfun), next_bb)
if (!gimple_seq_empty_p (phi_nodes (bb)))
{
edge e;
edge_iterator ei;
FOR_EACH_EDGE (e, ei, bb->preds)
- eliminate_phi (e, g);
+ eliminate_phi (e, &g);
set_phi_nodes (bb, NULL);
/* We can't redirect EH edges in RTL land, so we need to do this
here. Redirection happens only when splitting is necessary,
if (e->insns.r && (e->flags & EDGE_EH)
&& !single_pred_p (e->dest))
{
- rtx insns = e->insns.r;
+ rtx_insn *insns = e->insns.r;
basic_block bb;
- e->insns.r = NULL_RTX;
+ e->insns.r = NULL;
bb = split_edge (e);
single_pred_edge (bb)->insns.r = insns;
}
ei_next (&ei);
}
}
-
- delete_elim_graph (g);
}
{
bitmap values = NULL;
var_map map;
- unsigned i;
- map = coalesce_ssa_name ();
+ for_all_parms (create_default_def, NULL);
+ map = init_var_map (num_ssa_names);
+ coalesce_ssa_name (map);
/* Return to viewing the variable list as just all reference variables after
coalescing has been performed. */
- partition_view_normal (map, false);
+ partition_view_normal (map);
if (dump_file && (dump_flags & TDF_DETAILS))
{
sa->map = map;
sa->values = values;
- sa->partition_has_default_def = BITMAP_ALLOC (NULL);
- for (i = 1; i < num_ssa_names; i++)
+ sa->partitions_for_parm_default_defs = get_parm_default_def_partitions (map);
+ sa->partitions_for_undefined_values = get_undefined_value_partitions (map);
+}
+
+
+/* If not already done so for basic block BB, assign increasing uids
+ to each of its instructions. */
+
+static void
+maybe_renumber_stmts_bb (basic_block bb)
+{
+ unsigned i = 0;
+ gimple_stmt_iterator gsi;
+
+ if (!bb->aux)
+ return;
+ bb->aux = NULL;
+ for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- tree t = ssa_name (i);
- if (t && SSA_NAME_IS_DEFAULT_DEF (t))
- {
- int p = var_to_partition (map, t);
- if (p != NO_PARTITION)
- bitmap_set_bit (sa->partition_has_default_def, p);
- }
+ gimple *stmt = gsi_stmt (gsi);
+ gimple_set_uid (stmt, i);
+ i++;
+ }
+}
+
+
+/* Return true if we can determine that the SSA_NAMEs RESULT (a result
+ of a PHI node) and ARG (one of its arguments) conflict. Return false
+ otherwise, also when we simply aren't sure. */
+
+static bool
+trivially_conflicts_p (basic_block bb, tree result, tree arg)
+{
+ use_operand_p use;
+ imm_use_iterator imm_iter;
+ gimple *defa = SSA_NAME_DEF_STMT (arg);
+
+ /* If ARG isn't defined in the same block it's too complicated for
+ our little mind. */
+ if (gimple_bb (defa) != bb)
+ return false;
+
+ FOR_EACH_IMM_USE_FAST (use, imm_iter, result)
+ {
+ gimple *use_stmt = USE_STMT (use);
+ if (is_gimple_debug (use_stmt))
+ continue;
+ /* Now, if there's a use of RESULT that lies outside this basic block,
+ then there surely is a conflict with ARG. */
+ if (gimple_bb (use_stmt) != bb)
+ return true;
+ if (gimple_code (use_stmt) == GIMPLE_PHI)
+ continue;
+ /* The use now is in a real stmt of BB, so if ARG was defined
+ in a PHI node (like RESULT) both conflict. */
+ if (gimple_code (defa) == GIMPLE_PHI)
+ return true;
+ maybe_renumber_stmts_bb (bb);
+ /* If the use of RESULT occurs after the definition of ARG,
+ the two conflict too. */
+ if (gimple_uid (defa) < gimple_uid (use_stmt))
+ return true;
}
+
+ return false;
}
insert_backedge_copies (void)
{
basic_block bb;
- gimple_stmt_iterator gsi;
+ gphi_iterator gsi;
- FOR_EACH_BB (bb)
+ mark_dfs_back_edges ();
+
+ FOR_EACH_BB_FN (bb, cfun)
{
+ /* Mark block as possibly needing calculation of UIDs. */
+ bb->aux = &bb->aux;
+
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
{
- gimple phi = gsi_stmt (gsi);
+ gphi *phi = gsi.phi ();
tree result = gimple_phi_result (phi);
- tree result_var;
size_t i;
- if (!is_gimple_reg (result))
+ if (virtual_operand_p (result))
continue;
- result_var = SSA_NAME_VAR (result);
for (i = 0; i < gimple_phi_num_args (phi); i++)
{
tree arg = gimple_phi_arg_def (phi, i);
edge e = gimple_phi_arg_edge (phi, i);
-
- /* If the argument is not an SSA_NAME, then we will need a
- constant initialization. If the argument is an SSA_NAME with
- a different underlying variable then a copy statement will be
- needed. */
- if ((e->flags & EDGE_DFS_BACK)
- && (TREE_CODE (arg) != SSA_NAME
- || SSA_NAME_VAR (arg) != result_var))
+ /* We are only interested in copies emitted on critical
+ backedges. */
+ if (!(e->flags & EDGE_DFS_BACK)
+ || !EDGE_CRITICAL_P (e))
+ continue;
+
+ /* If the argument is not an SSA_NAME, then we will need a
+ constant initialization. If the argument is an SSA_NAME then
+ a copy statement may be needed. First handle the case
+ where we cannot insert before the argument definition. */
+ if (TREE_CODE (arg) != SSA_NAME
+ || (gimple_code (SSA_NAME_DEF_STMT (arg)) == GIMPLE_PHI
+ && trivially_conflicts_p (bb, result, arg)))
{
tree name;
- gimple stmt, last = NULL;
+ gassign *stmt;
+ gimple *last = NULL;
gimple_stmt_iterator gsi2;
gsi2 = gsi_last_bb (gimple_phi_arg_edge (phi, i)->src);
/* In theory the only way we ought to get back to the
start of a loop should be with a COND_EXPR or GOTO_EXPR.
- However, better safe than sorry.
+ However, better safe than sorry.
If the block ends with a control statement or
something that might throw, then we have to
insert this assignment before the last
continue;
}
- /* Create a new instance of the underlying variable of the
+ /* Create a new instance of the underlying variable of the
PHI result. */
- stmt = gimple_build_assign (result_var,
+ name = copy_ssa_name (result);
+ stmt = gimple_build_assign (name,
gimple_phi_arg_def (phi, i));
- name = make_ssa_name (result_var, stmt);
- gimple_assign_set_lhs (stmt, name);
+
+ /* copy location if present. */
+ if (gimple_phi_arg_has_location (phi, i))
+ gimple_set_location (stmt,
+ gimple_phi_arg_location (phi, i));
/* Insert the new statement into the block and update
the PHI node. */
gsi_insert_after (&gsi2, stmt, GSI_NEW_STMT);
SET_PHI_ARG_DEF (phi, i, name);
}
+ /* Insert a copy before the definition of the backedge value
+ and adjust all conflicting uses. */
+ else if (trivially_conflicts_p (bb, result, arg))
+ {
+ gimple *def = SSA_NAME_DEF_STMT (arg);
+ if (gimple_nop_p (def)
+ || gimple_code (def) == GIMPLE_PHI)
+ continue;
+ tree name = copy_ssa_name (result);
+ gimple *stmt = gimple_build_assign (name, result);
+ imm_use_iterator imm_iter;
+ gimple *use_stmt;
+ /* The following matches trivially_conflicts_p. */
+ FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, result)
+ {
+ if (gimple_bb (use_stmt) != bb
+ || (gimple_code (use_stmt) != GIMPLE_PHI
+ && (maybe_renumber_stmts_bb (bb), true)
+ && gimple_uid (use_stmt) > gimple_uid (def)))
+ {
+ use_operand_p use;
+ FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
+ SET_USE (use, name);
+ }
+ }
+ gimple_stmt_iterator gsi = gsi_for_stmt (def);
+ gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
+ }
}
}
+
+ /* Unmark this block again. */
+ bb->aux = NULL;
}
}
if (sa->values)
BITMAP_FREE (sa->values);
delete_var_map (sa->map);
- BITMAP_FREE (sa->partition_has_default_def);
+ BITMAP_FREE (sa->partitions_for_parm_default_defs);
+ BITMAP_FREE (sa->partitions_for_undefined_values);
memset (sa, 0, sizeof *sa);
}
projects / thirdparty / gcc.git / blobdiff