GitLab

Bugzilla Link	984
Created on	Jun 19, 2012 21:45
Resolution	FIXED
Resolved on	Jul 08, 2012 19:07
Version	svn
OS	Linux
Architecture	PC

Extended Description

A simple unit test for AWLF now fails, due to lost extrema.
The problem is that, if I compile with this:
cd ~/sac/testsuite/optimizations/awlf
sac2c prd2AKD.sac -doawlf -nowlf -nocyc -bopt:glf  >crud.glf
I get this code fragment in crud.glf:
  _flat_5 = [ shp ];
  _idc_46, _icc_34_pred = _non_neg_val_V_( _flat_5);
...
  _flat_0 = [ shp ];
What we want is to have all references to _flat_5 that
follow the _non_neg_val_V_( _flat_5) to become references
to _idc_46. The assignment of _flat_0 is, in a sense,
a violation of this, because _flat_0 does not carry the
AVIS_MIN generated by the guard.
The code that inserts the guards is correct as it stands.
The _flat_0 assign exists by the end of TC (phase 7).
So, we want to get rid of the common expression before
we insert constraints, so we clearly need a CSE/DCR traversal
in CWC, just before ICC. Ah, you mean, like this?
      cse      : Applying common subexpression elimination
      dcr      : Removing dead code
      icc      : Inserting Conformity Checks
Hmmm. Let's look at what we have in iota() after that DCR:
  _flat_5 = [ shp ];
  _flat_4 = [ shp ];
  _flat_3 = 0;
  _flat_2 = _mul_SxV_( _flat_3, _flat_4);
  _flat_1 = 0;
  _flat_0 = [ shp ];
Not exactly what we were hoping for.
CSE never traverses iota(), but it does traverse a lot of wrappers:
grep CSEfundef crud.cwcdcr 
   CSEfundef: CSE: Begin traversing (wrapper) partitionIntersectMax
   CSEfundef: CSE: Done traversing (wrapper) partitionIntersectMax
   CSEfundef: CSE: Begin traversing (wrapper) partitionSlicer
   CSEfundef: CSE: Done traversing (wrapper) partitionSlicer
   CSEfundef: CSE: Begin traversing (wrapper) isPartitionIntersectNull
   CSEfundef: CSE: Done traversing (wrapper) isPartitionIntersectNull
   CSEfundef: CSE: Begin traversing (wrapper) partitionIntersectMin
   CSEfundef: CSE: Done traversing (wrapper) partitionIntersectMin
   CSEfundef: CSE: Begin traversing (wrapper) adjustLacFunParams
   CSEfundef: CSE: Done traversing (wrapper) adjustLacFunParams
   CSEfundef: CSE: Begin traversing (wrapper) main
   CSEfundef: CSE: Done traversing (wrapper) main
   CSEfundef: CSE: Begin traversing (wrapper) prod
   CSEfundef: CSE: Done traversing (wrapper) prod
   CSEfundef: CSE: Begin traversing (wrapper) adjustLacFunParamsReshape
   CSEfundef: CSE: Done traversing (wrapper) adjustLacFunParamsReshape
   CSEfundef: CSE: Begin traversing (wrapper) eq
   CSEfundef: CSE: Done traversing (wrapper) eq
   CSEfundef: CSE: Begin traversing (wrapper) eq
   CSEfundef: CSE: Done traversing (wrapper) eq
   CSEfundef: CSE: Begin traversing (wrapper) eq
   CSEfundef: CSE: Done traversing (wrapper) eq
   CSEfundef: CSE: Begin traversing (wrapper) eq
   CSEfundef: CSE: Done traversing (wrapper) eq
   CSEfundef: CSE: Begin traversing (wrapper) eq
   CSEfundef: CSE: Done traversing (wrapper) eq
   CSEfundef: CSE: Begin traversing (wrapper) gridFiller
   CSEfundef: CSE: Done traversing (wrapper) gridFiller
   CSEfundef: CSE: Begin traversing (wrapper) zero
   CSEfundef: CSE: Done traversing (wrapper) zero
   CSEfundef: CSE: Begin traversing (wrapper) zero
   CSEfundef: CSE: Done traversing (wrapper) zero
   CSEfundef: CSE: Begin traversing (wrapper) zero
   CSEfundef: CSE: Done traversing (wrapper) zero
   CSEfundef: CSE: Begin traversing (wrapper) zero
   CSEfundef: CSE: Done traversing (wrapper) zero
   CSEfundef: CSE: Begin traversing (wrapper) zero
   CSEfundef: CSE: Done traversing (wrapper) zero
   CSEfundef: CSE: Begin traversing (wrapper) partitionMax
   CSEfundef: CSE: Done traversing (wrapper) partitionMax
   CSEfundef: CSE: Begin traversing function iota__Cond_0
   CSEfundef: CSE: Done traversing function iota__Cond_0
I am not sure where to go from here. This unit test did work
properly some time ago.