unroll/unroll-and-jam more powerful; add additional affine expr builder methods
- use previously added analysis/simplification to infer multiple of unroll
factor trip counts, making loop unroll/unroll-and-jam more general.
- for loop unroll, support bounds that are single result affine map's with the
same set of operands. For unknown loop bounds, loop unroll will now work as
long as trip count can be determined to be a multiple of unroll factor.
- extend getConstantTripCount to deal with single result affine map's with the
same operands. move it to mlir/Analysis/LoopAnalysis.cpp
- add additional builder utility methods for affine expr arithmetic
(difference, mod/floordiv/ceildiv w.r.t postitive constant). simplify code to
use the utility methods.
- move affine analysis routines to AffineAnalysis.cpp/.h from
AffineStructures.cpp/.h.
- Rename LoopUnrollJam to LoopUnrollAndJam to match class name.
- add an additional simplification for simplifyFloorDiv, simplifyCeilDiv
- Rename AffineMap::getNumOperands() getNumInputs: an affine map by itself does
not have operands. Operands are passed to it through affine_apply, from loop
bounds/if condition's, etc., operands are stored in the latter.
This should be sufficiently powerful for now as far as unroll/unroll-and-jam go for TPU
code generation, and can move to other analyses/transformations.
Loop nests like these are now unrolled without any cleanup loop being generated.
for %i = 1 to 100 {
// unroll factor 4: no cleanup loop will be generated.
for %j = (d0) -> (d0) (%i) to (d0) -> (5*d0 + 3) (%i) {
%x = "foo"(%j) : (affineint) -> i32
}
}
for %i = 1 to 100 {
// unroll factor 4: no cleanup loop will be generated.
for %j = (d0) -> (d0) (%i) to (d0) -> (d0 - d mod 4 - 1) (%i) {
%y = "foo"(%j) : (affineint) -> i32
}
}
for %i = 1 to 100 {
for %j = (d0) -> (d0) (%i) to (d0) -> (d0 + 128) (%i) {
%x = "foo"() : () -> i32
}
}
TODO(bondhugula): extend this to LoopUnrollAndJam as well in the next CL (with minor
changes).
PiperOrigin-RevId: 212661212
Previously the error could mislead into thinking it was a parser bug instead of the input being erroneous. Update to make it clearer.
PiperOrigin-RevId: 212271145
Ensure delimiters are absent where not expected. This is only checked in the case where operand count is known. This allows for the currently accepted case where there is a operand list with no delimiter and variable number of operands (which could be empty), followed by a delimited operand list.
PiperOrigin-RevId: 212202064
loop counts. Improve / refactor loop unroll / loop unroll and jam.
- add utility to remove single iteration loops.
- use this utility to promote single iteration loops after unroll/unroll-and-jam
- use loopUnrollByFactor for loopUnrollFull and remove most of the latter.
- add methods for getting constant loop trip count
PiperOrigin-RevId: 212039569
- Compress the identifier/kind of a Function into a single word.
- Eliminate otherFailure from verifier now that we always have a location
- Eliminate the error string from the verifier now that we always have
locations.
- Simplify the parser's handling of fn forward references, using the location
tracked by the function.
PiperOrigin-RevId: 211985101
terminators. Improve mlir-opt to print better location info in the split-files
case.
Before:
error: unexpected error: branch has 2 operands, but target block has 1
br bb1(%0tensorflow/mlir#1, %0tensorflow/mlir#0 : i17, i1)
^
after:
invalid.mlir split at line tensorflow/mlir#305:6:3: error: unexpected error: branch has 2 operands, but target block has 1
br bb1(%0tensorflow/mlir#1, %0tensorflow/mlir#0 : i17, i1)
^
It still isn't optimal (it would be better to have just the original file and
line number but is a step forward, and doing the optimal thing would be a lot
more complicated.
PiperOrigin-RevId: 211917067
- handle floordiv/ceildiv in AffineExprFlattener; update the simplification to
work even if mod/floordiv/ceildiv expressions appearing in the tree can't be eliminated.
- refactor the flattening / analysis to move it out of lib/Transforms/
- fix MutableAffineMap::isMultipleOf
- add AffineBinaryOpExpr:getAdd/getMul/... utility methods
PiperOrigin-RevId: 211540536
- Add a new -verify mode to the mlir-opt tool that allows writing test cases
for optimization and other passes that produce diagnostics.
- Refactor existing the -check-parser-errors flag to mlir-opt into a new
-split-input-file option which is orthogonal to -verify.
- Eliminate the special error hook the parser maintained and use the standard
MLIRContext's one instead.
- Enhance the default MLIRContext error reporter to print file/line/col of
errors when it is available.
- Add new createChecked() methods to the builder that create ops and invoke
the verify hook on them, use this to detected unhandled code in the
RaiseControlFlow pass.
- Teach mlir-opt about expected-error @+, it previously only worked with @-
PiperOrigin-RevId: 211305770
Outside of IR/
- simplify a MutableAffineMap by flattening the affine expressions
- add a simplify affine expression pass that uses this analysis
- update the FlatAffineConstraints API (to be used in the next CL)
In IR:
- add isMultipleOf and getKnownGCD for AffineExpr, and make the in-IR
simplication of simplifyMod simpler and more powerful.
- rename the AffineExpr visitor methods to distinguish b/w visiting and
walking, and to simplify API names based on context.
The next CL will use some of these for the loop unrolling/unroll-jam to make
the detection for the need of cleanup loop powerful/non-trivial.
A future CL will finally move this simplification to FlatAffineConstraints to
make it more powerful. For eg., currently, even if a mod expr appearing in a
part of the expression tree can't be simplified, the whole thing won't be
simplified.
PiperOrigin-RevId: 211012256
- for test purposes, the unroll-jam pass unroll jams the first outermost loop.
While on this:
- fix StmtVisitor to allow overriding of function to iterate walk over children
of a stmt.
PiperOrigin-RevId: 210644813
This CL also includes two other minor changes:
- change the implemented syntax from 'if (cond)' to 'if cond', as specified by MLIR spec.
- a minor fix to the implementation of the ForStmt.
PiperOrigin-RevId: 210618122
This commit creates a static constexpr limit for the IntegerType
bitwidth and uses it. The check had to be moved because Token is
not aware of IR/Type and it was a sign the abstraction leaked:
bitwidth limit is not a property of the Token but of the IntegerType.
Added a positive and a negative test at the limit.
PiperOrigin-RevId: 210388192
This commit adds 2 tests:
1. a negative test in which the simplification of expression does not seem satisfactory.
This test should be updated once expression simplification works reasonably.
2. a positive test in which floordiv and ceildiv return the same result, properly enforced with CHECK-NOT
PiperOrigin-RevId: 210286267
This commit replaces // CHECK-EMPTY because it is an extremely confusing way of
allowing (but not checking for) empty lines. The problem is that // CHECK-EMPTY
is **only a comment** and does not do anything.
I originally tried to use // CHECK-EMPTY: but errors occured due to missing
newlines.
The intended behavior of the test is to enforce nothing (not even a newline)
is printed and the proper way to check for this is to use CHECK-NOT.
Thanks to @rxwei for helping me figure out to use CHECK-NOT properly.
PiperOrigin-RevId: 210286262
This revamps implementation of the loop bounds in the ForStmt, using general representation that supports operands. The frequent case of constant bounds is supported
via special access methods.
This also includes:
- Operand iterators for the Statement class.
- OpPointer::is() method to query the class of the Operation.
- Support for the bound shorthand notation parsing and printing.
- Validity checks for the bound operands used as dim ids and symbols
I didn't mean this CL to be so large. It just happened this way, as one thing led to another.
PiperOrigin-RevId: 210204858
new VectorOrTensorType class that provides a common interface between vector
and tensor since a number of operations will be uniform across them (including
extract_element). Improve the LoadOp verifier.
I also updated the MLIR spec doc as well.
PiperOrigin-RevId: 209953189
FlatAffineConstraints, and MutableAffineMap.
All four classes introduced reside in lib/Analysis and are not meant to be
used in the IR (from lib/IR or lib/Parser/). They are all mutable, alloc'ed,
dealloc'ed - although with their fields pointing to immutable affine
expressions (AffineExpr *).
While on this, update simplifyMod to fold mod to a zero when possible.
PiperOrigin-RevId: 209618437
- Have the parser rewrite forward references to their resolved values at the
end of parsing.
- Implement verifier support for detecting malformed function attrs.
- Add efficient query for (in general, recursive) attributes to tell if they
contain a function.
As part of this, improve other general infrastructure:
- Implement support for verifying OperationStmt's in ml functions, refactoring
and generalizing support for operations in the verifier.
- Refactor location handling code in mlir-opt to have the non-error expecting
form of mlir-opt invocations to report error locations precisely.
- Fix parser to detect verifier failures and report them through errorReporter
instead of printing the error and crashing.
This regresses the location info for verifier errors in the parser that were
previously ascribed to the function. This will get resolved in future patches
by adding support for function attributes, which we can use to manage location
information.
PiperOrigin-RevId: 209600980
resolver support.
Still TODO are verifier support (to make sure you don't use an attribute for a
function in another module) and the TODO in ModuleParser::finalizeModule that I
will handle in the next patch.
PiperOrigin-RevId: 209361648
Collect loops through a post order walk instead of a pre-order so that loops
are collected from inner loops are collected before outer surrounding ones.
Add a complex test case.
PiperOrigin-RevId: 209041057
print floating point in a structured form that we know can round trip,
enumerate attributes in the visitor so we print affine mapping attributes
symbolically (the majority of the testcase updates).
We still have an issue where the hexadecimal floating point syntax is reparsed
as an integer, but that can evolve in subsequent patches.
PiperOrigin-RevId: 208828876
This patch passes the raw, unescaped value through to the rest of the stack. Partial escaping is a total pain to deal with, so we either need to implement escaping properly (ideally using a third party library like absl, I don't think LLVM has one that can handle the proper gamut of escape codes) or don't escape. I chose the latter for this patch.
PiperOrigin-RevId: 208608945
Prior to this CL, return statement had no explicit representation in MLIR. Now, it is represented as ReturnOp standard operation and is pretty printed according to the return statement syntax. This way statement walkers can process ML function return operands without making special case for them.
PiperOrigin-RevId: 208092424
- introduce affine integer sets into the IR
- parse and print affine integer sets (both inline or outlined) similar to
affine maps
- use integer set for IfStmt's conditional, and implement parsing of IfStmt's
conditional
- fixed an affine expr paren omission bug while one this.
TODO: parse/represent/print MLValue operands to affine integer set references.
PiperOrigin-RevId: 207779408
encapsulates an operation that is yet to be created. This is a patch towards
custom ops providing create methods that don't need to be templated, allowing
them to move out of line in the future.
PiperOrigin-RevId: 207725557
- fix/complete forStmt cloning for unrolling to work for outer loops
- create IV const's only when needed
- test outer loop unrolling by creating a short trip count unroll pass for
loops with trip counts <= <parameter>
- add unrolling test cases for multiple op results, outer loop unrolling
- fix/clean up StmtWalker class while on this
- switch unroll loop iterator values from i32 to affineint
PiperOrigin-RevId: 207645967
Unrelated minor change - remove OperationStmt::dropReferences(). Since MLFunction does not have cyclic operand references (it's an AST) destruction can be safely done w/o a special pass to drop references.
PiperOrigin-RevId: 207583024
- Implement a diagnostic hook in one of the paths in mlir-opt which
captures and reports the diagnostics nicely.
- Have the parser capture simple location information from the parser
indicating where each op came from in the source .mlir file.
- Add a verifyDominance() method to MLFuncVerifier to demo this, resolving b/112086163
- Add some PrettyStackTrace handlers to make crashes in the testsuite easier
to track down.
PiperOrigin-RevId: 207488548
- deal with non-operation stmt's (if/for stmt's) in loops being unrolled
(unrolling of non-innermost loops works).
- update uses in unrolled bodies to use results of new operations that may be
introduced in the unrolled bodies.
Unrolling now works for all kinds of loop nests - perfect nests, imperfect
nests, loops at any depth, and with any kind of operation in the body. (IfStmt
support not done, hence untested there).
Added missing dump/print method for StmtBlock.
TODO: add test case for outer loop unrolling.
PiperOrigin-RevId: 207314286
MLFunctions.
- MLStmt cloning and IV replacement
- While at this, fix the innermostLoopGatherer to actually gather all the
innermost loops (it was stopping its walk at the first innermost loop it
found)
- Improve comments for MLFunction statement classes, fix inheritance order.
- Fixed StmtBlock destructor.
PiperOrigin-RevId: 207049173
- simplify operations with identity elements (multiply by 1, add with 0).
- simplify successive add/mul: fold constants, propagate constants to the
right.
- simplify floordiv and ceildiv when divisors are constants, and the LHS is a
multiply expression with RHS constant.
- fix an affine expression printing bug on paren emission.
- while on this, fix affine-map test cases file (memref's using layout maps
that were duplicates of existing ones should be emitted pointing to the
unique'd one).
PiperOrigin-RevId: 207046738
generalize the asmprinters handling of pretty names to allow arbitrary sugar to
be dumped on various constructs. Give CFG function arguments nice "arg0" names
like MLFunctions get, and give constant integers pretty names like %c37 for a
constant 377
PiperOrigin-RevId: 206953080
Fix b/112039912 - we were recording 'i' instead of '%i' for loop induction variables causing "use of undefined SSA value" error.
PiperOrigin-RevId: 206884644
Two problems: 1) we didn't visit the types in ops correctly, and 2) the
general "T" version of the OpAsmPrinter inserter would match things like
MemRefType& and print it directly.
PiperOrigin-RevId: 206863642
This is doing it in a suboptimal manner by recombining [integer period literal] into a string literal and parsing that via to_float.
PiperOrigin-RevId: 206855106
This is still (intentionally) generating redundant parens for nested tightly
binding expressions, but I think that is reasonable for readability sake.
This also print x-y instead of x-(y*1)
PiperOrigin-RevId: 206847212
Chris Lattner