Index: llvm/include/llvm/Analysis/ScalarEvolution.h =================================================================== --- llvm/include/llvm/Analysis/ScalarEvolution.h +++ llvm/include/llvm/Analysis/ScalarEvolution.h @@ -655,6 +655,13 @@ /// Return a SCEV for the constant 1 of a specific type. const SCEV *getOne(Type *Ty) { return getConstant(Ty, 1); } + /// Return a SCEV for the constant \p Power of two. + const SCEV *getPowerOfTwo(Type *Ty, unsigned Power) { + auto Val = APInt::getZero(getTypeSizeInBits(Ty)); + Val.setBit(Power); + return getConstant(Val); + } + /// Return a SCEV for the constant -1 of a specific type. const SCEV *getMinusOne(Type *Ty) { return getConstant(Ty, -1, /*isSigned=*/true); Index: llvm/unittests/Analysis/ScalarEvolutionTest.cpp =================================================================== --- llvm/unittests/Analysis/ScalarEvolutionTest.cpp +++ llvm/unittests/Analysis/ScalarEvolutionTest.cpp @@ -1744,4 +1744,26 @@ }); } +TEST_F(ScalarEvolutionsTest, CheckGetPowerOfTwo) { + LLVMContext C; + SMDiagnostic Err; + std::unique_ptr M = parseAssemblyString("define void @foo(i64 %x) { " + " ret void " + "} ", + Err, C); + + ASSERT_TRUE(M && "Could not parse module?"); + ASSERT_TRUE(!verifyModule(*M) && "Must have been well formed!"); + + runWithSE(*M, "foo", [](Function &F, LoopInfo &LI, ScalarEvolution &SE) { + auto *X = SE.getSCEV(getArgByName(F, "x")); + Type *Ty = X->getType(); + for (unsigned short i = 0; i < 64; ++i) { + EXPECT_TRUE(dyn_cast(SE.getPowerOfTwo(Ty, i)) + ->getValue() + ->equalsInt(1ULL << i)); + } + }); +} + } // end namespace llvm