immediate_use_iterator_d Struct Reference
#include <tree-flow.h>
Collaboration diagram for immediate_use_iterator_d:
Data Fields | |
| ssa_use_operand_t * | imm_use |
| ssa_use_operand_t * | end_p |
| ssa_use_operand_t | iter_node |
| ssa_use_operand_t * | next_imm_name |
Detailed Description
Immediate use lists are used to directly access all uses for an SSA name and get pointers to the statement for each use. The structure ssa_use_operand_d consists of PREV and NEXT pointers to maintain the list. A USE pointer, which points to address where the use is located and a LOC pointer which can point to the statement where the use is located, or, in the case of the root node, it points to the SSA name itself. The list is anchored by an occurrence of ssa_operand_d *in* the ssa_name node itself (named 'imm_uses'). This node is uniquely identified by having a NULL USE pointer. and the LOC pointer pointing back to the ssa_name node itself. This node forms the base for a circular list, and initially this is the only node in the list. Fast iteration allows each use to be examined, but does not allow any modifications to the uses or stmts. Normal iteration allows insertion, deletion, and modification. the iterator manages this by inserting a marker node into the list immediately before the node currently being examined in the list. this marker node is uniquely identified by having null stmt *and* a null use pointer. When iterating to the next use, the iteration routines check to see if the node after the marker has changed. if it has, then the node following the marker is now the next one to be visited. if not, the marker node is moved past that node in the list (visualize it as bumping the marker node through the list). this continues until the marker node is moved to the original anchor position. the marker node is then removed from the list. If iteration is halted early, the marker node must be removed from the list before continuing.
Field Documentation
| ssa_use_operand_t* immediate_use_iterator_d::end_p |
Referenced by end_imm_use_stmt_p(), end_readonly_imm_use_p(), first_imm_use_stmt(), and first_readonly_imm_use().
| ssa_use_operand_t* immediate_use_iterator_d::imm_use |
| ssa_use_operand_t immediate_use_iterator_d::iter_node |
| ssa_use_operand_t* immediate_use_iterator_d::next_imm_name |
Referenced by first_imm_use_on_stmt(), first_imm_use_stmt(), and next_imm_use_on_stmt().
The documentation for this struct was generated from the following file:
