rewrite_dom_walker Class Reference
Inheritance diagram for rewrite_dom_walker:
Collaboration diagram for rewrite_dom_walker:
Public Member Functions | |
| rewrite_dom_walker (cdi_direction direction) | |
| virtual void | before_dom_children (basic_block) |
| virtual void | after_dom_children (basic_block) |
| void | walk (basic_block) |
Constructor & Destructor Documentation
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inline |
References is_gimple_reg(), and SSA_NAME_VAR.
Member Function Documentation
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virtual |
Called after visiting all the statements in basic block BB and all of its dominator children. Restore CURRDEFS to its original value.
Restore CURRDEFS to its original state.
If we recorded an SSA_NAME, then make the SSA_NAME the
current definition of its underlying variable. Note that
if the SSA_NAME is not for a GIMPLE register, the symbol
being defined is stored in the next slot in the stack.
This mechanism is needed because an SSA name for a
non-register symbol may be the definition for more than
one symbol (e.g., SFTs, aliased variables, etc). If we recorded anything else, it must have been a _DECL
node and its current reaching definition must have been
NULL.
Reimplemented from dom_walker.
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virtual |
SSA Rewriting Step 1. Initialization, create a block local stack of reaching definitions for new SSA names produced in this block (BLOCK_DEFS). Register new definitions for every PHI node in the block.
Mark the unwind point for this block.
Step 1. Register new definitions for every PHI node in the block. Conceptually, all the PHI nodes are executed in parallel and each PHI node introduces a new version for the associated variable.
Step 2. Rewrite every variable used in each statement in the block with its immediate reaching definitions. Update the current definition of a variable when a new real or virtual definition is found.
Step 3. Visit all the successor blocks of BB looking for PHI nodes. For every PHI node found, add a new argument containing the current reaching definition for the variable and the edge through which that definition is reaching the PHI node.
Reimplemented from dom_walker.
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inherited |
Walk the dominator tree.
Recursively walk the dominator tree. BB is the basic block we are currently visiting.
Don't worry about unreachable blocks.
Callback for subclasses to do custom things before we have walked
the dominator children, but before we walk statements. Mark the current BB to be popped out of the recursion stack
once children are processed. NULL is used to mark pop operations in the recursion stack.
Callback allowing subclasses to do custom things after we have
walked dominator children, but before we walk statements.
References bb_postorder, inverted_post_order_compute(), last_basic_block, n_basic_blocks, and postorder_num.
The documentation for this class was generated from the following file:
