class AffineParser(BaseParser):
_BINOP_PRECEDENCE: ClassVar = {
"+": 10,
"-": 10,
"*": 20,
"ceildiv": 20,
"floordiv": 20,
"mod": 20,
}
def __init__(self, state: ParserState[MLIRTokenKind]) -> None:
self._resume_from(state)
def _get_parse_optional_bare_id(
self, dims: list[str], syms: list[str]
) -> Callable[[], AffineExpr | None]:
def parse_optional_bare_id():
if (token := self._parse_optional_token(MLIRTokenKind.BARE_IDENT)) is None:
return
# Handle bare id
span = token.span
bare_id = span.text
if bare_id in dims:
return AffineExpr.dimension(dims.index(bare_id))
elif bare_id in syms:
return AffineExpr.symbol(syms.index(bare_id))
else:
raise ParseError(span, f"Identifier not in space {bare_id}")
return parse_optional_bare_id
def _parse_primary(
self, parse_optional_bare_id: Callable[[], AffineExpr | None]
) -> AffineExpr:
"""
primary ::= `(` affine-expr `)`
| bare-id
| integer-literal
| `-` primary
"""
if (bare_id := parse_optional_bare_id()) is not None:
return bare_id
current_token = self._consume_token()
match current_token.kind:
case MLIRTokenKind.L_PAREN:
# Handle parentheses
expr = self._parse_affine_expr(parse_optional_bare_id)
self._parse_token(MLIRTokenKind.R_PAREN, "Expected closing parenthesis")
return expr
case MLIRTokenKind.INTEGER_LIT:
# Handle integer literal
return AffineExpr.constant(
current_token.kind.get_int_value(current_token.span)
)
case MLIRTokenKind.MINUS:
# Handle negative primary
return -self._parse_primary(parse_optional_bare_id)
case _:
raise ParseError(current_token.span, "Expected primary expression")
def _get_token_precedence(self) -> int:
return self._BINOP_PRECEDENCE.get(self._current_token.text, -1)
def _create_binop_expr(
self, lhs: AffineExpr, rhs: AffineExpr, binop: MLIRToken
) -> AffineExpr:
match binop.text:
case "+":
return lhs + rhs
case "-":
return lhs - rhs
case "*":
return lhs * rhs
case "ceildiv":
return lhs.ceil_div(rhs)
case "floordiv":
return lhs // rhs
case "mod":
return lhs % rhs
case _:
raise ParseError(binop.span, f"Unknown binary operator {binop.text}")
def _parse_binop_rhs(
self,
lhs: AffineExpr,
prec: int,
parse_optional_bare_id: Callable[[], AffineExpr | None],
) -> AffineExpr:
while True:
tok_prec = self._get_token_precedence()
# This works even if the token does not exist, since -1 is returned.
if tok_prec < prec:
return lhs
# Get the binop
binop = self._consume_token()
# Parse the primary expression after the binary operator.
rhs = self._parse_primary(parse_optional_bare_id)
next_prec = self._get_token_precedence()
if tok_prec < next_prec:
# Increase the precision of the current operator to parse
# it before the next one in case they have same precedence.
rhs = self._parse_binop_rhs(rhs, tok_prec + 1, parse_optional_bare_id)
lhs = self._create_binop_expr(lhs, rhs, binop)
# TODO: Extend to semi-affine maps
def _parse_affine_expr(
self, parse_optional_bare_id: Callable[[], AffineExpr | None]
) -> AffineExpr:
"""
affine-expr ::= `(` affine-expr `)`
| `-`? integer-literal
| bare-id
| `-`affine-expr
| `-`? integer-literal `*` affine-expr
| affine-expr `ceildiv` integer-literal
| affine-expr `floordiv` integer-literal
| affine-expr `mod` integer-literal
| affine-expr `+` affine-expr
| affine-expr `-` affine-expr
"""
lhs = self._parse_primary(parse_optional_bare_id)
return self._parse_binop_rhs(lhs, 0, parse_optional_bare_id)
def _parse_multi_affine_expr(
self, parse_optional_bare_id: Callable[[], AffineExpr | None]
) -> list[AffineExpr]:
"""
multi-affine-expr ::= `(` `)`
| `(` affine-expr (`,` affine-expr)* `)`
"""
def parse_expr() -> AffineExpr:
return self._parse_affine_expr(parse_optional_bare_id)
return self.parse_comma_separated_list(self.Delimiter.PAREN, parse_expr)
# TODO: Extend to semi-affine maps; see https://github.com/xdslproject/xdsl/issues/1087
def _parse_affine_constraint(
self, parse_optional_bare_id: Callable[[], AffineExpr | None]
) -> AffineConstraintExpr:
"""
affine-expr ::= `(` affine-expr `)`
| `-`? integer-literal
| bare-id
| `-`affine-expr
| `-`? integer-literal `*` affine-expr
| affine-expr `ceildiv` integer-literal
| affine-expr `floordiv` integer-literal
| affine-expr `mod` integer-literal
| affine-expr `+` affine-expr
| affine-expr `-` affine-expr
"""
lhs = self._parse_affine_expr(parse_optional_bare_id)
op = self._consume_token().text + self._consume_token().text
if op not in set(k.value for k in AffineConstraintKind):
self.raise_error(
f"Expected one of {', '.join(f'`{k.value}`' for k in AffineConstraintKind)}, got {op}."
)
op = AffineConstraintKind(op)
rhs = self._parse_affine_expr(parse_optional_bare_id)
return AffineConstraintExpr(op, lhs, rhs)
def _parse_multi_affine_constaint(
self, parse_optional_bare_id: Callable[[], AffineExpr | None]
) -> list[AffineConstraintExpr]:
"""
multi-affine-expr ::= `(` `)`
| `(` affine-expr (`,` affine-expr)* `)`
"""
def parse_constraint() -> AffineConstraintExpr:
return self._parse_affine_constraint(parse_optional_bare_id)
return self.parse_comma_separated_list(self.Delimiter.PAREN, parse_constraint)
def _parse_affine_space(self) -> tuple[list[str], list[str]]:
"""
dims ::= `(` ssa-use-list? `)`
syms ::= `[` ssa-use-list? `]`
affine-space ::= dims syms?
"""
def parse_id() -> str:
return self._parse_token(
MLIRTokenKind.BARE_IDENT, "Expected identifier"
).text
# Parse dimensions
dims = self.parse_comma_separated_list(self.Delimiter.PAREN, parse_id)
# Parse optional symbols
if self._current_token.kind != MLIRTokenKind.L_SQUARE:
syms = []
else:
syms = self.parse_comma_separated_list(self.Delimiter.SQUARE, parse_id)
# TODO: Do not allow duplicate ids.
return dims, syms
def parse_affine_map(self) -> AffineMap:
"""
affine-map
::= affine-space `->` multi-affine-expr
"""
# Parse affine space
dims, syms = self._parse_affine_space()
# Parse : delimiter
self._parse_token(MLIRTokenKind.ARROW, "Expected `->`")
# Parse list of affine expressions
exprs = self._parse_multi_affine_expr(
self._get_parse_optional_bare_id(dims, syms)
)
# Create map and return.
return AffineMap(len(dims), len(syms), tuple(exprs))
def parse_affine_set(self) -> AffineSet:
"""
affine-map
::= affine-space `:` `(` (affine-constraint)* `)`
"""
# Parse affine space
dims, syms = self._parse_affine_space()
# Parse : delimiter
self._parse_token(MLIRTokenKind.COLON, "Expected `:`")
# Parse list of affine expressions
constraints = self._parse_multi_affine_constaint(
self._get_parse_optional_bare_id(dims, syms)
)
# Create map and return.
return AffineSet(len(dims), len(syms), tuple(constraints))
def _get_parse_optional_ssa_value(
self,
) -> tuple[Callable[[], AffineExpr | None], dict[str, int], list[Span]]:
"""
Returns function to parse an affine symbol expr represented by an SSA value
identifier, the dictionary mapping SSA value name to the corresponding
symbol index, and the list of each name's first-occurence span (in
symbol-index order), all populated by the function as it encounters
new values.
"""
symbol_by_ssa_name: dict[str, int] = {}
spans: list[Span] = []
def parse_optional_ssa_value() -> AffineExpr | None:
if (
ident_token := self._parse_optional_token(MLIRTokenKind.PERCENT_IDENT)
) is not None:
ident = ident_token.span.text
try:
symbol = symbol_by_ssa_name[ident]
except KeyError:
symbol = len(symbol_by_ssa_name)
symbol_by_ssa_name[ident] = symbol
spans.append(ident_token.span)
return AffineExpr.symbol(symbol)
return parse_optional_ssa_value, symbol_by_ssa_name, spans
def parse_affine_map_of_ssa_ids(self) -> tuple[AffineMap, Sequence[Span]]:
"""
Parse an affine map where ssa values can be used inside the expressions.
```
`[` affine-expr (`,` affine-expr)* `]`
```
"""
parse_optional_bare_id, symbol_by_ssa_name, spans = (
self._get_parse_optional_ssa_value()
)
exprs = self.parse_comma_separated_list(
self.Delimiter.SQUARE,
lambda: self._parse_affine_expr(parse_optional_bare_id),
)
return AffineMap(0, len(symbol_by_ssa_name), tuple(exprs)), tuple(spans)