[Mlir-commits] [mlir] a4b2363 - [mlir] Don't assert when simplifying certain `AffineExpr`s (#78855)

[llvmlistbot at llvm.org]

Author: Felix Schneider
Date: 2024-03-19T10:43:02+01:00
New Revision: a4b23638d23d603001c19285a7c7535a8ce81317

URL: https://github.com/llvm/llvm-project/commit/a4b23638d23d603001c19285a7c7535a8ce81317
DIFF: https://github.com/llvm/llvm-project/commit/a4b23638d23d603001c19285a7c7535a8ce81317.diff

LOG: [mlir] Don't assert when simplifying certain `AffineExpr`s (#78855)

Currently, `simplifyMul()` asserts that either `lhs` or `rhs` is
symbolic or constant. This method is called by the overloaded `*`
operator for `AffineExpr`s which leads to a crash when building a
multiplication expression where neither operand is symbolic or constant.
This patch returns a `nullptr` from `simplifyMul()` to signal that the
expression could not be simplified instead.

Fix https://github.com/llvm/llvm-project/issues/75770

Added: 
    mlir/unittests/IR/AffineExprTest.cpp

Modified: 
    mlir/lib/IR/AffineExpr.cpp
    mlir/unittests/IR/CMakeLists.txt

Removed: 
    


################################################################################
diff  --git a/mlir/lib/IR/AffineExpr.cpp b/mlir/lib/IR/AffineExpr.cpp
index 56a2d850ad3b67..94562d0f15a24a 100644
--- a/mlir/lib/IR/AffineExpr.cpp
+++ b/mlir/lib/IR/AffineExpr.cpp
@@ -774,7 +774,8 @@ static AffineExpr simplifyMul(AffineExpr lhs, AffineExpr rhs) {
     return getAffineConstantExpr(lhsConst.getValue() * rhsConst.getValue(),
                                  lhs.getContext());
 
-  assert(lhs.isSymbolicOrConstant() || rhs.isSymbolicOrConstant());
+  if (!lhs.isSymbolicOrConstant() && !rhs.isSymbolicOrConstant())
+    return nullptr;
 
   // Canonicalize the mul expression so that the constant/symbolic term is the
   // RHS. If both the lhs and rhs are symbolic, swap them if the lhs is a

diff  --git a/mlir/unittests/IR/AffineExprTest.cpp b/mlir/unittests/IR/AffineExprTest.cpp
new file mode 100644
index 00000000000000..ff154eb29807c3
--- /dev/null
+++ b/mlir/unittests/IR/AffineExprTest.cpp
@@ -0,0 +1,32 @@
+//===- AffineExprTest.cpp - unit tests for affine expression API ----------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/IR/AffineExpr.h"
+#include "mlir/IR/Builders.h"
+#include "gtest/gtest.h"
+
+using namespace mlir;
+
+// Test creating AffineExprs using the overloaded binary operators.
+TEST(AffineExprTest, constructFromBinaryOperators) {
+  MLIRContext ctx;
+  OpBuilder b(&ctx);
+
+  auto d0 = b.getAffineDimExpr(0);
+  auto d1 = b.getAffineDimExpr(1);
+
+  auto sum = d0 + d1;
+  auto 
diff erence = d0 - d1;
+  auto product = d0 * d1;
+  auto remainder = d0 % d1;
+
+  ASSERT_EQ(sum.getKind(), AffineExprKind::Add);
+  ASSERT_EQ(
diff erence.getKind(), AffineExprKind::Add);
+  ASSERT_EQ(product.getKind(), AffineExprKind::Mul);
+  ASSERT_EQ(remainder.getKind(), AffineExprKind::Mod);
+}

diff  --git a/mlir/unittests/IR/CMakeLists.txt b/mlir/unittests/IR/CMakeLists.txt
index e7e9c3b5651693..71f8f449756ec0 100644
--- a/mlir/unittests/IR/CMakeLists.txt
+++ b/mlir/unittests/IR/CMakeLists.txt
@@ -1,5 +1,6 @@
 add_mlir_unittest(MLIRIRTests
   AdaptorTest.cpp
+  AffineExprTest.cpp
   AffineMapTest.cpp
   AttributeTest.cpp
   DialectTest.cpp