7 Commits

Author SHA1 Message Date
Uday Bondhugula
dfc752e42b Generate strided DMAs from -dma-generate
- generate DMAs correctly now using strided DMAs where needed
- add support for multi-level/nested strides; op still supports one level of
  stride for now.

Other things
- add test case for  symbolic lower/upper bound; cases where the DMA buffer
  size can't be bounded by a known constant
- add test case for dynamic shapes where the DMA buffers are however bounded by
  constants
- refactor some of the '-dma-generate' code

PiperOrigin-RevId: 224584529
2019-03-29 14:23:19 -07:00
Uday Bondhugula
a92130880e Complete multiple unhandled cases for DmaGeneration / getMemRefRegion;
update/improve/clean up API.

- update FlatAffineConstraints::getConstBoundDifference; return constant
  differences between symbolic affine expressions, look at equalities as well.
- fix buffer size computation when generating DMAs symbolic in outer loops,
  correctly handle symbols at various places (affine access maps, loop bounds,
  loop IVs outer to the depth at which DMA generation is being done)
- bug fixes / complete some TODOs for getMemRefRegion
- refactor common code b/w memref dependence check and getMemRefRegion
- FlatAffineConstraints API update; added methods employ trivial checks /
  detection - sufficient to handle hyper-rectangular cases in a precise way
  while being fast / low complexity. Hyper-rectangular cases fall out as
  trivial cases for these methods while other cases still do not cause failure
  (either return conservative or return failure that is handled by the caller).

PiperOrigin-RevId: 224229879
2019-03-29 14:18:22 -07:00
Uday Bondhugula
89c41fdca1 FlatAffineConstraints::composeMap: return failure instead of asserting on semi-affine maps
FlatAffineConstraints::composeMap: should return false instead of asserting on
a semi-affine map. Make getMemRefRegion just propagate false when encountering
semi-affine maps (instead of crashing!)
PiperOrigin-RevId: 223828743
2019-03-29 14:14:56 -07:00
Uday Bondhugula
a619b5c295 Debug output / logging memref sizes in DMA generation + related changes
- Add method to get a memref's size in bytes
- clean up a loop tiling pass helper (NFC)

PiperOrigin-RevId: 223422077
2019-03-29 14:12:56 -07:00
Uday Bondhugula
fff1efbaf5 Updates to transformation/analysis passes/utilities. Update DMA generation pass
and getMemRefRegion() to work with specified loop depths; add support for
outgoing DMAs, store op's.

- add support for getMemRefRegion symbolic in outer loops - hence support for
  DMAs symbolic in outer surrounding loops.

- add DMA generation support for outgoing DMAs (store op's to lower memory
  space); extend getMemoryRegion to store op's. -memref-bound-check now works
  with store op's as well.

- fix dma-generate (references to the old memref in the dma_start op were also
  being replaced with the new buffer); we need replace all memref uses to work
  only on a subset of the uses - add a new optional argument for
  replaceAllMemRefUsesWith. update replaceAllMemRefUsesWith to take an optional
  'operation' argument to serve as a filter - if provided, only those uses that
  are dominated by the filter are replaced.

- Add missing print for attributes for dma_start, dma_wait op's.

- update the FlatAffineConstraints API

PiperOrigin-RevId: 221889223
2019-03-29 14:00:51 -07:00
Uday Bondhugula
e0623d4b86 Automatic DMA generation for simple cases.
- constant bounded memory regions, static shapes, no handling of
  overlapping/duplicate regions (through union) for now; also only, load memory
  op's.
- add build methods for DmaStartOp, DmaWaitOp.
- move getMemoryRegion() into Analysis/Utils and expose it.
- fix addIndexSet, getMemoryRegion() post switch to exclusive upper bounds;
  update test cases for memref-bound-check and memref-dependence-check for
  exclusive bounds (missed in a previous CL)

PiperOrigin-RevId: 220729810
2019-03-29 13:53:14 -07:00
Uday Bondhugula
18e666702c Generalize / improve DMA transfer overlap; nested and multiple DMA support; resolve
multiple TODOs.

- replace the fake test pass (that worked on just the first loop in the
  MLFunction) to perform DMA pipelining on all suitable loops.
- nested DMAs work now (DMAs in an outer loop, more DMAs in nested inner loops)
- fix bugs / assumptions: correctly copy memory space and elemental type of source
  memref for double buffering.
- correctly identify matching start/finish statements, handle multiple DMAs per
  loop.
- introduce dominates/properlyDominates utitilies for MLFunction statements.
- move checkDominancePreservationOnShifts to LoopAnalysis.h; rename it
  getShiftValidity
- refactor getContainingStmtPos -> findAncestorStmtInBlock - move into
  Analysis/Utils.h; has two users.
- other improvements / cleanup for related API/utilities
- add size argument to dma_wait - for nested DMAs or in general, it makes it
  easy to obtain the size to use when lowering the dma_wait since we wouldn't
  want to identify the matching dma_start, and more importantly, in general/in the
  future, there may not always be a dma_start dominating the dma_wait.
- add debug information in the pass

PiperOrigin-RevId: 217734892
2019-03-29 13:32:28 -07:00