/* Routines for liveness in SSA trees.
- Copyright (C) 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2007, 2008, 2010
+ Free Software Foundation, Inc.
Contributed by Andrew MacLeod <amacleod@redhat.com>
This file is part of GCC.
-/* Used to create the variable mapping when we go out of SSA form.
+/* Used to create the variable mapping when we go out of SSA form.
Mapping from an ssa_name to a partition number is maintained, as well as
partition number to back to ssa_name. A partition can also be represented
- by a non-ssa_name variable. This allows ssa_names and their partition to
+ by a non-ssa_name variable. This allows ssa_names and their partition to
be coalesced with live on entry compiler variables, as well as eventually
- having real compiler variables assigned to each partition as part of the
- final stage of going of of ssa.
+ having real compiler variables assigned to each partition as part of the
+ final stage of going of of ssa.
Non-ssa_names maintain their partition index in the variable annotation.
This data structure also supports "views", which work on a subset of all
- partitions. This allows the coalescer to decide what partitions are
+ partitions. This allows the coalescer to decide what partitions are
interesting to it, and only work with those partitions. Whenever the view
is changed, the partition numbers change, but none of the partition groupings
change. (ie, it is truly a view since it doesn't change anything)
int *partition_to_view;
int *view_to_partition;
- /* Mapping of partition numbers to variables. */
- tree *partition_to_var;
-
/* Current number of partitions in var_map based on the current view. */
unsigned int num_partitions;
} *var_map;
-/* Partition number of a non ssa-name variable. */
-#define VAR_ANN_PARTITION(ann) (ann->partition)
-/* Index iot the basevar table of a non ssa-name variable. */
+/* Index to the basevar table of a non ssa-name variable. */
#define VAR_ANN_BASE_INDEX(ann) (ann->base_index)
extern void delete_var_map (var_map);
extern void dump_var_map (FILE *, var_map);
extern int var_union (var_map, tree, tree);
-extern void change_partition_var (var_map, tree, int);
extern void partition_view_normal (var_map, bool);
extern void partition_view_bitmap (var_map, bitmap, bool);
#ifdef ENABLE_CHECKING
}
-/* Given partition index I from MAP, return the variable which represents that
+/* Given partition index I from MAP, return the variable which represents that
partition. */
-
+
static inline tree
partition_to_var (var_map map, int i)
{
+ tree name;
if (map->view_to_partition)
i = map->view_to_partition[i];
i = partition_find (map->var_partition, i);
- return map->partition_to_var[i];
+ name = ssa_name (i);
+ return name;
}
-/* Given ssa_name VERSION, if it has a partition in MAP, return the var it
+/* Given ssa_name VERSION, if it has a partition in MAP, return the var it
is associated with. Otherwise return NULL. */
-static inline tree
+static inline tree
version_to_var (var_map map, int version)
{
int part;
part = map->partition_to_view[part];
if (part == NO_PARTITION)
return NULL_TREE;
-
+
return partition_to_var (map, part);
}
-
-/* Given VAR, return the partition number in MAP which contains it.
+
+/* Given VAR, return the partition number in MAP which contains it.
NO_PARTITION is returned if it's not in any partition. */
static inline int
var_to_partition (var_map map, tree var)
{
- var_ann_t ann;
int part;
- if (TREE_CODE (var) == SSA_NAME)
- {
- part = partition_find (map->var_partition, SSA_NAME_VERSION (var));
- if (map->partition_to_view)
- part = map->partition_to_view[part];
- }
- else
- {
- ann = var_ann (var);
- if (ann && ann->out_of_ssa_tag)
- part = VAR_ANN_PARTITION (ann);
- else
- part = NO_PARTITION;
- }
+ part = partition_find (map->var_partition, SSA_NAME_VERSION (var));
+ if (map->partition_to_view)
+ part = map->partition_to_view[part];
return part;
}
static inline int
basevar_index (var_map map, int partition)
{
- gcc_assert (partition >= 0
- && partition <= (int) num_var_partitions (map));
+ gcc_checking_assert (partition >= 0
+ && partition <= (int) num_var_partitions (map));
return map->partition_to_base_index[partition];
}
-/* This routine registers a partition for SSA_VAR with MAP. Any unregistered
- partitions may be filtered out by a view later. */
+/* This routine registers a partition for SSA_VAR with MAP. Any unregistered
+ partitions may be filtered out by a view later. */
static inline void
-register_ssa_partition (var_map map, tree ssa_var)
+register_ssa_partition (var_map map ATTRIBUTE_UNUSED,
+ tree ssa_var ATTRIBUTE_UNUSED)
{
- int version;
-
#if defined ENABLE_CHECKING
register_ssa_partition_check (ssa_var);
#endif
-
- version = SSA_NAME_VERSION (ssa_var);
- if (map->partition_to_var[version] == NULL_TREE)
- map->partition_to_var[version] = ssa_var;
}
-/* ---------------- live on entry/exit info ------------------------------
+/* ---------------- live on entry/exit info ------------------------------
This structure is used to represent live range information on SSA based
trees. A partition map must be provided, and based on the active partitions,
live-on-entry information and live-on-exit information can be calculated.
- As well, partitions are marked as to whether they are global (live
+ As well, partitions are marked as to whether they are global (live
outside the basic block they are defined in).
- The live-on-entry information is per block. It provide a bitmap for
- each block which has a bit set for each partition that is live on entry to
+ The live-on-entry information is per block. It provide a bitmap for
+ each block which has a bit set for each partition that is live on entry to
that block.
The live-on-exit information is per block. It provides a bitmap for each
block indicating which partitions are live on exit from the block.
- For the purposes of this implementation, we treat the elements of a PHI
+ For the purposes of this implementation, we treat the elements of a PHI
as follows:
Uses in a PHI are considered LIVE-ON-EXIT to the block from which they
The Def of a PHI node is *not* considered live on entry to the block.
It is considered to be "define early" in the block. Picture it as each
- block having a stmt (or block-preheader) before the first real stmt in
+ block having a stmt (or block-preheader) before the first real stmt in
the block which defines all the variables that are defined by PHIs.
-
+
----------------------------------------------------------------------- */
static inline int
partition_is_global (tree_live_info_p live, int p)
{
- gcc_assert (live->global);
+ gcc_checking_assert (live->global);
return bitmap_bit_p (live->global, p);
}
-/* Return the bitmap from LIVE representing the live on entry blocks for
+/* Return the bitmap from LIVE representing the live on entry blocks for
partition P. */
static inline bitmap
live_on_entry (tree_live_info_p live, basic_block bb)
{
- gcc_assert (live->livein);
- gcc_assert (bb != ENTRY_BLOCK_PTR);
- gcc_assert (bb != EXIT_BLOCK_PTR);
+ gcc_checking_assert (live->livein
+ && bb != ENTRY_BLOCK_PTR
+ && bb != EXIT_BLOCK_PTR);
return live->livein[bb->index];
}
static inline bitmap
live_on_exit (tree_live_info_p live, basic_block bb)
{
- gcc_assert (live->liveout);
- gcc_assert (bb != ENTRY_BLOCK_PTR);
- gcc_assert (bb != EXIT_BLOCK_PTR);
+ gcc_checking_assert (live->liveout
+ && bb != ENTRY_BLOCK_PTR
+ && bb != EXIT_BLOCK_PTR);
return live->liveout[bb->index];
}
/* Return the partition map which the information in LIVE utilizes. */
-static inline var_map
+static inline var_map
live_var_map (tree_live_info_p live)
{
return live->map;
/* Merge the live on entry information in LIVE for partitions P1 and P2. Place
the result into P1. Clear P2. */
-static inline void
+static inline void
live_merge_and_clear (tree_live_info_p live, int p1, int p2)
{
- gcc_assert (live->livein[p1]);
- gcc_assert (live->livein[p2]);
+ gcc_checking_assert (live->livein[p1] && live->livein[p2]);
bitmap_ior_into (live->livein[p1], live->livein[p2]);
bitmap_zero (live->livein[p2]);
}
/* Mark partition P as live on entry to basic block BB in LIVE. */
-static inline void
+static inline void
make_live_on_entry (tree_live_info_p live, basic_block bb , int p)
{
bitmap_set_bit (live->livein[bb->index], p);
/* From tree-ssa-ter.c */
-extern tree *find_replaceable_exprs (var_map);
-extern void dump_replaceable_exprs (FILE *, tree *);
+extern bitmap find_replaceable_exprs (var_map);
+extern void dump_replaceable_exprs (FILE *, bitmap);
#endif /* _TREE_SSA_LIVE_H */
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