Commit Graph

59 Commits

Author SHA1 Message Date
River Riddle a3d9ccaecb Replace the walkOps/visitOperationInst variants from the InstWalkers with the Instruction variants.
PiperOrigin-RevId: 232322030
2019-03-29 16:10:24 -07:00
Uday Bondhugula b26900dce5 Update dma-generate pass to (1) work on blocks of instructions (instead of just
loops), (2) take into account fast memory space capacity and lower 'dmaDepth'
to fit, (3) add location information for debug info / errors

- change dma-generate pass to work on blocks of instructions (start/end
  iterators) instead of 'for' loops; complete TODOs - allows DMA generation for
  straightline blocks of operation instructions interspersed b/w loops
- take into account fast memory capacity: check whether memory footprint fits
  in fastMemoryCapacity parameter, and recurse/lower the depth at which DMA
  generation is performed until it does fit in the provided memory
- add location information to MemRefRegion; any insufficient fast memory
  capacity errors or debug info w.r.t dma generation shows location information
- allow DMA generation pass to be instantiated with a fast memory capacity
  option (besides command line flag)

- change getMemRefRegion to return unique_ptr's
- change getMemRefFootprintBytes to work on a 'Block' instead of 'ForInst'
- other helper methods; add postDomInstFilter option for
  replaceAllMemRefUsesWith; drop forInst->walkOps, add Block::walkOps methods

Eg. output

$ mlir-opt  -dma-generate -dma-fast-mem-capacity=1 /tmp/single.mlir
/tmp/single.mlir:9:13: error: Total size of all DMA buffers' for this block exceeds fast memory capacity

        for %i3 = (d0) -> (d0)(%i1) to (d0) -> (d0 + 32)(%i1) {
            ^

$ mlir-opt -debug-only=dma-generate  -dma-generate -dma-fast-mem-capacity=400 /tmp/single.mlir
/tmp/single.mlir:9:13: note: 8 KiB of DMA buffers in fast memory space for this block

        for %i3 = (d0) -> (d0)(%i1) to (d0) -> (d0 + 32)(%i1) {

PiperOrigin-RevId: 232297044
2019-03-29 16:09:52 -07:00
Uday Bondhugula f99a44a7cd Address documentation/readability related comments from cl/227252907 on memref
store forwarding - NFC.

PiperOrigin-RevId: 229561933
2019-03-29 15:20:59 -07:00
Uday Bondhugula 21baf86a2f Extend loop-fusion's slicing utility + other fixes / updates
- refactor toAffineFromEq and the code surrounding it; refactor code into
  FlatAffineConstraints::getSliceBounds
- add FlatAffineConstraints methods to detect identifiers as mod's and div's of other
  identifiers
- add FlatAffineConstraints::getConstantLower/UpperBound
- Address b/122118218 (don't assert on invalid fusion depths cmdline flags -
  instead, don't do anything; change cmdline flags
  src-loop-depth -> fusion-src-loop-depth
- AffineExpr/Map print method update: don't fail on null instances (since we have
  a wrapper around a pointer, it's avoidable); rationale: dump/print methods should
  never fail if possible.
- Update memref-dataflow-opt to add an optimization to avoid a unnecessary call to
  IsRangeOneToOne when it's trivially going to be true.
- Add additional test cases to exercise the new support
- update a few existing test cases since the maps are now generated uniformly with
  all destination loop operands appearing for the backward slice
- Fix projectOut - fix wrong range for getBestElimCandidate.
- Fix for getConstantBoundOnDimSize() - didn't show up in any test cases since
  we didn't have any non-hyperrectangular ones.

PiperOrigin-RevId: 228265152
2019-03-29 15:03:20 -07:00
Uday Bondhugula 56b3640b94 Misc readability and doc / code comment related improvements - NFC
- when SSAValue/MLValue existed, code at several places was forced to create additional
  aggregate temporaries of SmallVector<SSAValue/MLValue> to handle the conversion; get
  rid of such redundant code

- use filling ctors instead of explicit loops

- for smallvectors, change insert(list.end(), ...) -> append(...

- improve comments at various places

- turn getMemRefAccess into MemRefAccess ctor and drop duplicated
  getMemRefAccess. In the next CL, provide getAccess() accessors for load,
  store, DMA op's to return a MemRefAccess.

PiperOrigin-RevId: 228243638
2019-03-29 15:02:41 -07:00
Chris Lattner 7974889f54 Update and generalize various passes to work on both CFG and ML functions,
simplifying them in minor ways.  The only significant cleanup here
is the constant folding pass.  All the other changes are simple and easy,
but this is still enough to shrink the compiler by 45LOC.

The one pass left to merge is the CSE pass, which will be move involved, so I'm
splitting it out to its own patch (which I'll tackle right after this).

This is step 28/n towards merging instructions and statements.

PiperOrigin-RevId: 227328115
2019-03-29 14:49:52 -07:00
Uday Bondhugula f12182157e Introduce PostDominanceInfo, fix properlyDominates() for Instructions
- introduce PostDominanceInfo in the right/complete way and use that for post
  dominance check in store-load forwarding
- replace all uses of Analysis/Utils::dominates/properlyDominates with
  DominanceInfo::dominates/properlyDominates
- drop all redundant copies of dominance methods in Analysis/Utils/
- in pipeline-data-transfer, replace dominates call with a much less expensive
  check; similarly, substitute dominates() in checkMemRefAccessDependence with
  a simpler check suitable for that context
- fix a bug in properlyDominates
- improve doc for 'for' instruction 'body'

PiperOrigin-RevId: 227320507
2019-03-29 14:48:44 -07:00
Uday Bondhugula 545f3ce430 Fix ASAN failure in memref-dataflow-opt
- memrefsToErase had duplicates inserted into it; switch to SmallPtrSet.

PiperOrigin-RevId: 227299306
2019-03-29 14:47:58 -07:00
Uday Bondhugula b9fe6be6d4 Introduce memref store to load forwarding - a simple memref dataflow analysis
- the load/store forwarding relies on memref dependence routines as well as
  SSA/dominance to identify the memref store instance uniquely supplying a value
  to a memref load, and replaces the result of that load with the value being
  stored. The memref is also deleted when possible if only stores remain.

- add methods for post dominance for MLFunction blocks.

- remove duplicated getLoopDepth/getNestingDepth - move getNestingDepth,
  getMemRefAccess, getNumCommonSurroundingLoops into Analysis/Utils (were
  earlier static)

- add a helper method in FlatAffineConstraints - isRangeOneToOne.

PiperOrigin-RevId: 227252907
2019-03-29 14:47:28 -07:00