Drop AffineMap::Null and IntegerSet::Null

Addresses b/122486036

This CL addresses some leftover crumbs in AffineMap and IntegerSet by removing
the Null method and cleaning up the constructors.

As the ::Null uses were tracked down, opportunities appeared to untangle some
of the Parsing logic and make it explicit where AffineMap/IntegerSet have
ambiguous syntax. Previously, ambiguous cases were hidden behind the implicit
pointer values of AffineMap* and IntegerSet* that were passed as function
parameters. Depending the values of those pointers one of 3 behaviors could
occur.

This parsing logic convolution is one of the rare cases where I would advocate
for code duplication. The more proper fix would be to make the syntax
unambiguous or to allow some lookahead.

PiperOrigin-RevId: 231058512

1 files changed, 1 insertions, 1 deletions

diff --git a/mlir/lib/Transforms/PipelineDataTransfer.cpp b/mlir/lib/Transforms/PipelineDataTransfer.cpp
index 101a00eaf61..e72b9ef80df 100644
--- a/mlir/lib/Transforms/PipelineDataTransfer.cpp
+++ b/mlir/lib/Transforms/PipelineDataTransfer.cpp
@@ -127,7 +127,7 @@ static bool doubleBuffer(Value *oldMemRef, ForInst *forInst) {
   // replaceAllMemRefUsesWith will always succeed unless the forInst body has
   // non-deferencing uses of the memref.
   if (!replaceAllMemRefUsesWith(oldMemRef, newMemRef, ivModTwoOp->getResult(0),
-                                AffineMap::Null(), {},
+                                AffineMap(), {},
                                 &*forInst->getBody()->begin())) {
     LLVM_DEBUG(llvm::dbgs()
                    << "memref replacement for double buffering failed\n";);