[Mlir-commits] [mlir] ff5f8e5 - [MLIR][Presburger] removeTrivialRedundancy: skip unnecessary check for duplicate constraints (#138969)

[llvmlistbot at llvm.org]

Author: Leonid Gorbunov
Date: 2025-05-28T13:21:00+01:00
New Revision: ff5f8e513c6fb854cb11b05574c593c49f6f82d9

URL: https://github.com/llvm/llvm-project/commit/ff5f8e513c6fb854cb11b05574c593c49f6f82d9
DIFF: https://github.com/llvm/llvm-project/commit/ff5f8e513c6fb854cb11b05574c593c49f6f82d9.diff

LOG: [MLIR][Presburger] removeTrivialRedundancy: skip unnecessary check for duplicate constraints (#138969)

`removeTrivialRedundancy` first marks duplicate rows redundant, then
when multiple rows differ only by a constant term, it removes all but
one of them. Since the latter removes all but one duplicate row as well,
it is unnecessary (redundant!) to mark duplicate rows redundant. So we
remove this step.

Added: 
    

Modified: 
    mlir/lib/Analysis/Presburger/IntegerRelation.cpp

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Analysis/Presburger/IntegerRelation.cpp b/mlir/lib/Analysis/Presburger/IntegerRelation.cpp
index e1fd20fe48009..2181d9484f223 100644
--- a/mlir/lib/Analysis/Presburger/IntegerRelation.cpp
+++ b/mlir/lib/Analysis/Presburger/IntegerRelation.cpp
@@ -21,7 +21,6 @@
 #include "mlir/Analysis/Presburger/Simplex.h"
 #include "mlir/Analysis/Presburger/Utils.h"
 #include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/Sequence.h"
 #include "llvm/ADT/SmallBitVector.h"
@@ -45,7 +44,6 @@ using namespace mlir;
 using namespace presburger;
 
 using llvm::SmallDenseMap;
-using llvm::SmallDenseSet;
 
 std::unique_ptr<IntegerRelation> IntegerRelation::clone() const {
   return std::make_unique<IntegerRelation>(*this);
@@ -1824,8 +1822,6 @@ void IntegerRelation::removeTrivialRedundancy() {
   // for a given row.
   SmallDenseMap<ArrayRef<DynamicAPInt>, std::pair<unsigned, DynamicAPInt>>
       rowsWithoutConstTerm;
-  // To unique rows.
-  SmallDenseSet<ArrayRef<DynamicAPInt>, 8> rowSet;
 
   // Check if constraint is of the form <non-negative-constant> >= 0.
   auto isTriviallyValid = [&](unsigned r) -> bool {
@@ -1840,8 +1836,7 @@ void IntegerRelation::removeTrivialRedundancy() {
   SmallVector<bool, 256> redunIneq(getNumInequalities(), false);
   for (unsigned r = 0, e = getNumInequalities(); r < e; r++) {
     DynamicAPInt *rowStart = &inequalities(r, 0);
-    auto row = ArrayRef<DynamicAPInt>(rowStart, getNumCols());
-    if (isTriviallyValid(r) || !rowSet.insert(row).second) {
+    if (isTriviallyValid(r)) {
       redunIneq[r] = true;
       continue;
     }