Computes and exposes the dominance relation amongst blocks of a region.
See external documentation.
Source code in xdsl/irdl/dominance.py
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72 | class DominanceInfo:
"""
Computes and exposes the dominance relation amongst blocks of a region.
See external [documentation](https://en.wikipedia.org/w/index.php?title=Dominator_(graph_theory)&oldid=1189814332).
"""
_dominance: dict[Block, set[Block]]
def __init__(self, region: Region):
"""
Compute (improper) dominance.
See external [documentation](https://en.wikipedia.org/w/index.php?title=Dominator_(graph_theory)&oldid=1189814332).
"""
self._dominance = {}
# No block, no work
if not (region.blocks):
return
# Build the preceding relationship
pred: dict[Block, set[Block]] = {}
for b in region.blocks:
pred[b] = set()
for b in region.blocks:
if b.last_op is not None:
for s in b.last_op.successors:
pred[s].add(b)
# Get entry and other blocks
entry, *blocks = region.blocks
# The entry block is only dominated by itself
self._dominance[entry] = {entry}
# Instantiate other blocks dominators to all blocks
for b in blocks:
self._dominance[b] = set(region.blocks)
# Iteratively filter out dominators until it converges
changed = True
while changed:
changed = False
for b in blocks:
old = self._dominance[b].copy()
self._dominance[b] = {b} | (
set[Block].intersection(*(self._dominance[p] for p in pred[b]))
if pred[b]
else set()
)
if old != self._dominance[b]:
changed = True
def strictly_dominates(self, a: Block, b: Block) -> bool:
"""
Return if `a` *strictly* dominates `b`.
i.e., if it dominates `b` and is not `b`.
"""
if a is b:
return False
return self.dominates(a, b)
def dominates(self, a: Block, b: Block) -> bool:
"""
Return if `a` dominates `b`.
"""
return a in self._dominance[b]
|
__init__(region: Region)
Compute (improper) dominance.
See external documentation.
Source code in xdsl/irdl/dominance.py
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57 | def __init__(self, region: Region):
"""
Compute (improper) dominance.
See external [documentation](https://en.wikipedia.org/w/index.php?title=Dominator_(graph_theory)&oldid=1189814332).
"""
self._dominance = {}
# No block, no work
if not (region.blocks):
return
# Build the preceding relationship
pred: dict[Block, set[Block]] = {}
for b in region.blocks:
pred[b] = set()
for b in region.blocks:
if b.last_op is not None:
for s in b.last_op.successors:
pred[s].add(b)
# Get entry and other blocks
entry, *blocks = region.blocks
# The entry block is only dominated by itself
self._dominance[entry] = {entry}
# Instantiate other blocks dominators to all blocks
for b in blocks:
self._dominance[b] = set(region.blocks)
# Iteratively filter out dominators until it converges
changed = True
while changed:
changed = False
for b in blocks:
old = self._dominance[b].copy()
self._dominance[b] = {b} | (
set[Block].intersection(*(self._dominance[p] for p in pred[b]))
if pred[b]
else set()
)
if old != self._dominance[b]:
changed = True
|
strictly_dominates(a: Block, b: Block) -> bool
Return if a strictly dominates b.
i.e., if it dominates b and is not b.
Source code in xdsl/irdl/dominance.py
| def strictly_dominates(self, a: Block, b: Block) -> bool:
"""
Return if `a` *strictly* dominates `b`.
i.e., if it dominates `b` and is not `b`.
"""
if a is b:
return False
return self.dominates(a, b)
|
dominates(a: Block, b: Block) -> bool
Return if a dominates b.
Source code in xdsl/irdl/dominance.py
| def dominates(self, a: Block, b: Block) -> bool:
"""
Return if `a` dominates `b`.
"""
return a in self._dominance[b]
|