Commit Graph

1063 Commits

Author SHA1 Message Date
Uday Bondhugula 3e92be9c71 Move Pass.{h,cpp} from lib/IR/ to lib/Transforms/.
PiperOrigin-RevId: 208571437
2019-03-29 12:59:07 -07:00
Chris Lattner 8159186f57 Rework the cloning infrastructure for statements to be able to take and update
an operand mapping, which simplifies it a bit.  Implement cloning for IfStmt,
rename getThenClause() to getThen() which is unambiguous and less repetitive in
use cases.

PiperOrigin-RevId: 207915990
2019-03-29 12:57:38 -07:00
Uday Bondhugula d8490d8d4f Loop unrolling pass update
- 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
2019-03-29 12:56:16 -07:00
Uday Bondhugula 65b6e73245 Loop unrolling update.
- 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
2019-03-29 12:55:19 -07:00
Uday Bondhugula 2a003256ae MLStmt cloning and IV replacement for loop unrolling, add constant pool to
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
2019-03-29 12:53:02 -07:00
Tatiana Shpeisman 8189a12bce Clean up and extend MLFuncBuilder to allow creating statements in the middle of a statement block. Rename Statement::getFunction() and StmtBlock()::getFunction() to findFunction() to make it clear that this is not a constant time getter.
Fix b/112039912 - we were recording 'i' instead of '%i' for loop induction variables causing "use of undefined SSA value" error.

PiperOrigin-RevId: 206884644
2019-03-29 12:51:38 -07:00
Uday Bondhugula dfd48dc24c LoopUnroll post order walk: fix misleading naming
PiperOrigin-RevId: 206609084
2019-03-29 12:48:44 -07:00
Chris Lattner 12adbeb872 Prepare for implementation of TensorFlow passes:
- Sketch out a TensorFlow/IR directory that will hold op definitions and common TF support logic.  We will eventually have TensorFlow/TF2HLO, TensorFlow/Grappler, TensorFlow/TFLite, etc.
 - Add sketches of a Switch/Merge op definition, including some missing stuff like the TwoResults trait.  Add a skeleton of a pass to raise this form.
 - Beef up the Pass/FunctionPass definitions slightly, moving the common code out of LoopUnroll.cpp into a new IR/Pass.cpp file.
 - Switch ConvertToCFG.cpp to be a ModulePass.
 - Allow _ to start bare identifiers, since this is important for TF attributes.

PiperOrigin-RevId: 206502517
2019-03-29 12:47:25 -07:00
Uday Bondhugula 0af97111d2 Stmt visitors and walkers.
- Update InnermostLoopGatherer to use a post order traversal (linear
  time/single traversal).
- Drop getNumNestedLoops().
- Update isInnermost() to use the StmtWalker.

When using return values in conjunction with walkers, the StmtWalker CRTP
pattern doesn't appear to be of any use. It just requires overriding nearly all
of the methods, which is what InnermostLoopGatherer currently does. Please see
FIXME/ENLIGHTENME comments. TODO: figure this out from this CL discussion.

Note
- Comments on visitor/walker base class are out of date; will update when this
  CL is finalized.

PiperOrigin-RevId: 206340901
2019-03-29 12:46:17 -07:00
Tatiana Shpeisman 9ebd3c7df8 Implement MLValue, statement operands, operation statement operands and values. ML functions now have full support for expressing operations. Induction variables, function arguments and return values are still todo.
PiperOrigin-RevId: 206253643
2019-03-29 12:46:04 -07:00
Chris Lattner f964bad6d1 Implement a proper function list in module, which auto-maintain the parent
pointer, and ensure that functions are deleted when the module is destroyed.

This exposed the fact that MLFunction had no dtor, and that the dtor in
CFGFunction was broken with cyclic references.  Fix both of these problems.

PiperOrigin-RevId: 206051666
2019-03-29 12:43:57 -07:00
Uday Bondhugula a0abd666a7 Sketch out loop unrolling transformation.
- Implement a full loop unroll for innermost loops.
- Use it to implement a pass that unroll all the innermost loops of all
  mlfunction's in a module. ForStmt's parsed currently have constant trip
  counts (and constant loop bounds).
- Implement StmtVisitor based (Visitor pattern)

Loop IVs aren't currently parsed and represented as SSA values. Replacing uses
of loop IVs in unrolled bodies is thus a TODO. Class comments are sparse at some places - will add them after one round of comments.

A cmd-line flag triggers this for now.

Original:

mlfunc @loops() {
  for x = 1 to 100 step 2 {
    for x = 1 to 4 {
      "Const"(){value: 1} : () -> ()
    }
  }
  return
}

After unrolling:

mlfunc @loops() {
  for x = 1 to 100 step 2 {
    "Const"(){value: 1} : () -> ()
    "Const"(){value: 1} : () -> ()
    "Const"(){value: 1} : () -> ()
    "Const"(){value: 1} : () -> ()
  }
  return
}

PiperOrigin-RevId: 205933235
2019-03-29 12:43:01 -07:00
Tatiana Shpeisman 1b24c48b91 Scaffolding for convertToCFG pass that replaces all instances of ML functions with equivalent CFG functions. Traverses module MLIR, generates CFG functions (empty for now) and removes ML functions. Adds Transforms library and tests.
PiperOrigin-RevId: 205848367
2019-03-29 12:41:15 -07:00