[Mlir-commits] [mlir] 855cd84 - [MLIR][Presburger] normalizeDivisionByGCD: fix bug when constant term is negative

[Arjun P]

Author: Arjun P
Date: 2022-02-11T17:02:52+05:30
New Revision: 855cd847f7f54e7f05bbac94e386aee0d434f685

URL: https://github.com/llvm/llvm-project/commit/855cd847f7f54e7f05bbac94e386aee0d434f685
DIFF: https://github.com/llvm/llvm-project/commit/855cd847f7f54e7f05bbac94e386aee0d434f685.diff

LOG: [MLIR][Presburger] normalizeDivisionByGCD: fix bug when constant term is negative

Reviewed By: Groverkss

Differential Revision: https://reviews.llvm.org/D119531

Added: 
    

Modified: 
    mlir/lib/Analysis/Presburger/Utils.cpp
    mlir/unittests/Analysis/Presburger/IntegerPolyhedronTest.cpp

Removed: 
    


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diff  --git a/mlir/lib/Analysis/Presburger/Utils.cpp b/mlir/lib/Analysis/Presburger/Utils.cpp
index 48db035268fa6..c6f377acfa608 100644
--- a/mlir/lib/Analysis/Presburger/Utils.cpp
+++ b/mlir/lib/Analysis/Presburger/Utils.cpp
@@ -45,7 +45,7 @@ static void normalizeDivisionByGCD(SmallVectorImpl<int64_t> &dividend,
 
   // Normalize the dividend and the denominator.
   std::transform(dividend.begin(), dividend.end(), dividend.begin(),
-                 [gcd](int64_t &n) { return floor((double)(n / gcd)); });
+                 [gcd](int64_t &n) { return floorDiv(n, gcd); });
   divisor /= gcd;
 }
 

diff  --git a/mlir/unittests/Analysis/Presburger/IntegerPolyhedronTest.cpp b/mlir/unittests/Analysis/Presburger/IntegerPolyhedronTest.cpp
index d2d0df080633d..d3c40237c692d 100644
--- a/mlir/unittests/Analysis/Presburger/IntegerPolyhedronTest.cpp
+++ b/mlir/unittests/Analysis/Presburger/IntegerPolyhedronTest.cpp
@@ -794,6 +794,21 @@ TEST(IntegerPolyhedronTest, computeLocalReprNoRepr) {
   checkDivisionRepresentation(poly, divisions, denoms);
 }
 
+TEST(IntegerPolyhedronTest, computeLocalReprNegConstNormalize) {
+  MLIRContext context;
+  IntegerPolyhedron poly = parsePoly(
+      "(x, q) : (-1 - 3*x - 6 * q >= 0, 6 + 3*x + 6*q >= 0)", &context);
+  // Convert q to a local variable.
+  poly.convertDimToLocal(1, 2);
+
+  // q = floor((-1/3 - x)/2)
+  //   = floor((1/3) + (-1 - x)/2)
+  //   = floor((-1 - x)/2).
+  std::vector<SmallVector<int64_t, 8>> divisions = {{-1, 0, -1}};
+  SmallVector<unsigned, 8> denoms = {2};
+  checkDivisionRepresentation(poly, divisions, denoms);
+}
+
 TEST(IntegerPolyhedronTest, simplifyLocalsTest) {
   // (x) : (exists y: 2x + y = 1 and y = 2).
   IntegerPolyhedron poly(1, 0, 1);