Due to legacy reasons (ML/CFG function separation), regions in affine control
flow operations require contained blocks not to have terminators. This is
inconsistent with the notion of the block and may complicate code motion
between regions of affine control operations and other regions.
Introduce `affine.terminator`, a special terminator operation that must be used
to terminate blocks inside affine operations and transfers the control back to
he region enclosing the affine operation. For brevity and readability reasons,
allow `affine.for` and `affine.if` to omit the `affine.terminator` in their
regions when using custom printing and parsing format. The custom parser
injects the `affine.terminator` if it is missing so as to always have it
present in constructed operations.
Update transformations to account for the presence of terminator. In
particular, most code motion transformation between loops should leave the
terminator in place, and code motion between loops and non-affine blocks should
drop the terminator.
PiperOrigin-RevId: 240536998
a pointer. This makes it consistent with all the other methods in
FunctionPass, as well as with ModulePass::getModule(). NFC.
PiperOrigin-RevId: 240257910
inherited constructors, which is cleaner and means you can now use DimOp()
to get a null op, instead of having to use Instruction::getNull<DimOp>().
This removes another 200 lines of code.
PiperOrigin-RevId: 240068113
- change this for consistency - everything else similar takes/returns a
Function pointer - the FuncBuilder ctor,
Block/Value/Instruction::getFunction(), etc.
- saves a whole bunch of &s everywhere
PiperOrigin-RevId: 236928761
This CL changes dialect op source files (.h, .cpp, .td) to follow the following
convention:
<full-dialect-name>/<dialect-namespace>Ops.{h|cpp|td}
Builtin and standard dialects are specially treated, though. Both of them do
not have dialect namespace; the former is still named as BuiltinOps.* and the
latter is named as Ops.*.
Purely mechanical. NFC.
PiperOrigin-RevId: 236371358
This implements the lowering of `floordiv`, `ceildiv` and `mod` operators from
affine expressions to the arithmetic primitive operations. Integer division
rules in affine expressions explicitly require rounding towards either negative
or positive infinity unlike machine implementations that round towards zero.
In the general case, implementing `floordiv` and `ceildiv` using machine signed
division requires computing both the quotient and the remainder. When the
divisor is positive, this can be simplified by adjusting the dividend and the
quotient by one and switching signs.
In the current use cases, we are unlikely to encounter affine expressions with
negative divisors (affine divisions appear in loop transformations such as
tiling that guarantee that divisors are positive by construction). Therefore,
it is reasonable to use branch-free single-division implementation. In case of
affine maps, divisors can only be literals so we can check the sign and
implement the case for negative divisors when the need arises.
The affine lowering pass can still fail when applied to semi-affine maps
(division or modulo by a symbol).
PiperOrigin-RevId: 228668181
This change is mechanical and merges the LowerAffineApplyPass and
LowerIfAndForPass into a single LowerAffinePass. It makes a step towards
defining an "affine dialect" that would contain all polyhedral-related
constructs. The motivation for merging these two passes is based on retiring
MLFunctions and, eventually, transforming If and For statements into regular
operations. After that happens, LowerAffinePass becomes yet another
legalization.
PiperOrigin-RevId: 227566113
