tree_live_info_d Struct Reference

#include <tree-ssa-live.h>

Collaboration diagram for tree_live_info_d:

Data Fields
var_map	map
bitmap_head *	livein
bitmap_head *	liveout
int	num_blocks
int *	work_stack
int *	stack_top
bitmap_obstack	livein_obstack
bitmap_obstack	liveout_obstack

Detailed Description

---------------- 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
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
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
as follows:

   Uses in a PHI are considered LIVE-ON-EXIT to the block from which they
   originate. They are *NOT* considered live on entry to the block
   containing the PHI node.

   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
   the block which defines all the variables that are defined by PHIs.

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Field Documentation

livein

bitmap_head* tree_live_info_d::livein

Referenced by calculate_live_ranges(), delete_tree_live_info(), dump_live_info(), live_on_entry(), make_live_on_entry(), new_tree_live_info(), and set_var_live_on_entry().

livein_obstack

bitmap_obstack tree_live_info_d::livein_obstack

Referenced by calculate_live_ranges(), delete_tree_live_info(), and new_tree_live_info().

liveout

bitmap_head* tree_live_info_d::liveout

Referenced by calculate_live_on_exit(), delete_tree_live_info(), dump_live_info(), live_on_exit(), loe_visit_block(), new_tree_live_info(), and set_var_live_on_entry().

liveout_obstack

bitmap_obstack tree_live_info_d::liveout_obstack

Referenced by delete_tree_live_info(), and new_tree_live_info().

map

var_map tree_live_info_d::map

Referenced by build_ssa_conflict_graph(), calculate_live_on_exit(), dump_live_info(), live_var_map(), live_worklist(), loe_visit_block(), new_tree_live_info(), set_var_live_on_entry(), and verify_live_on_entry().

num_blocks

int tree_live_info_d::num_blocks

Referenced by new_tree_live_info().

stack_top

int* tree_live_info_d::stack_top

Referenced by live_worklist(), loe_visit_block(), and new_tree_live_info().

work_stack

int* tree_live_info_d::work_stack

Referenced by delete_tree_live_info(), live_worklist(), and new_tree_live_info().

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The documentation for this struct was generated from the following file:

• tree-ssa-live.h