[PATCH] D72784: [IR] fix crash in Constant::isElementWiseEqual() with FP types

[Sanjay Patel via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rG52b44902d059: [IR] fix crash in Constant::isElementWiseEqual() with FP types (authored by spatel).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72784/new/

https://reviews.llvm.org/D72784

Files:
  llvm/lib/IR/Constants.cpp
  llvm/unittests/IR/ConstantsTest.cpp


Index: llvm/unittests/IR/ConstantsTest.cpp
===================================================================
--- llvm/unittests/IR/ConstantsTest.cpp
+++ llvm/unittests/IR/ConstantsTest.cpp
@@ -586,7 +586,8 @@
 }
 
 // Check that undefined elements in vector constants are matched
-// correctly for both integer and floating-point types.
+// correctly for both integer and floating-point types. Just don't
+// crash on vectors of pointers (could be handled?).
 
 TEST(ConstantsTest, isElementWiseEqual) {
   LLVMContext Context;
@@ -607,7 +608,6 @@
   EXPECT_FALSE(C12U1->isElementWiseEqual(C12U2));
   EXPECT_FALSE(C12U21->isElementWiseEqual(C12U2));
 
-/* FIXME: This will crash.
   Type *FltTy = Type::getFloatTy(Context);
   Constant *CFU = UndefValue::get(FltTy);
   Constant *CF1 = ConstantFP::get(FltTy, 1.0);
@@ -621,7 +621,19 @@
   EXPECT_TRUE(CF12U1->isElementWiseEqual(CF1211));
   EXPECT_FALSE(CF12U2->isElementWiseEqual(CF12U1));
   EXPECT_FALSE(CF12U1->isElementWiseEqual(CF12U2));
-*/
+
+  PointerType *PtrTy = Type::getInt8PtrTy(Context);
+  Constant *CPU = UndefValue::get(PtrTy);
+  Constant *CP0 = ConstantPointerNull::get(PtrTy);
+
+  Constant *CP0000 = ConstantVector::get({CP0, CP0, CP0, CP0});
+  Constant *CP00U0 = ConstantVector::get({CP0, CP0, CPU, CP0});
+  Constant *CP00U = ConstantVector::get({CP0, CP0, CPU});
+
+  EXPECT_FALSE(CP0000->isElementWiseEqual(CP00U0));
+  EXPECT_FALSE(CP00U0->isElementWiseEqual(CP0000));
+  EXPECT_FALSE(CP0000->isElementWiseEqual(CP00U));
+  EXPECT_FALSE(CP00U->isElementWiseEqual(CP00U0));
 }
 
 }  // end anonymous namespace
Index: llvm/lib/IR/Constants.cpp
===================================================================
--- llvm/lib/IR/Constants.cpp
+++ llvm/lib/IR/Constants.cpp
@@ -286,12 +286,17 @@
   if (!isa<Constant>(Y) || !Ty->isVectorTy() || Ty != Y->getType())
     return false;
 
+  // TODO: Compare pointer constants?
+  if (!(Ty->getVectorElementType()->isIntegerTy() ||
+        Ty->getVectorElementType()->isFloatingPointTy()))
+    return false;
+
   // They may still be identical element-wise (if they have `undef`s).
-  // FIXME: This crashes on FP vector constants.
-  return match(ConstantExpr::getICmp(ICmpInst::Predicate::ICMP_EQ,
-                                     const_cast<Constant *>(this),
-                                     cast<Constant>(Y)),
-               m_One());
+  // Bitcast to integer to allow exact bitwise comparison for all types.
+  Type *IntTy = VectorType::getInteger(cast<VectorType>(Ty));
+  Constant *C0 = ConstantExpr::getBitCast(const_cast<Constant *>(this), IntTy);
+  Constant *C1 = ConstantExpr::getBitCast(cast<Constant>(Y), IntTy);
+  return match(ConstantExpr::getICmp(ICmpInst::ICMP_EQ, C0, C1), m_One());
 }
 
 bool Constant::containsUndefElement() const {


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