From f52d68165715d4af14776cab96c31fbba641e806 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sun, 24 Apr 2005 17:46:05 +0000 Subject: [PATCH] Eliminate cases where we could << by 64, which is undefined in C. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21500 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/InstructionCombining.cpp | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index bb224a1b5d2..ad60a75f326 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -691,7 +691,7 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) { // Form a mask of all bits from the lowest bit added through the top. uint64_t AddRHSHighBits = ~((AddRHSV & -AddRHSV)-1); - AddRHSHighBits &= (1ULL << C2->getType()->getPrimitiveSizeInBits())-1; + AddRHSHighBits &= ~0ULL >> (64-C2->getType()->getPrimitiveSizeInBits()); // See if the and mask includes all of these bits. uint64_t AddRHSHighBitsAnd = AddRHSHighBits & C2->getRawValue(); @@ -718,7 +718,7 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) { // highest order bit set. static bool isSignBit(ConstantInt *CI) { unsigned NumBits = CI->getType()->getPrimitiveSizeInBits(); - return (CI->getRawValue() & ~(-1LL << NumBits)) == (1ULL << (NumBits-1)); + return (CI->getRawValue() & (~0ULL >> (64-NumBits))) == (1ULL << (NumBits-1)); } /// RemoveNoopCast - Strip off nonconverting casts from the value. @@ -1427,7 +1427,7 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op, uint64_t AndRHSV = cast(AndRHS)->getRawValue(); // Clear bits that are not part of the constant. - AndRHSV &= (1ULL << AndRHS->getType()->getPrimitiveSizeInBits())-1; + AndRHSV &= ~0ULL >> (64-AndRHS->getType()->getPrimitiveSizeInBits()); // If there is only one bit set... if (isOneBitSet(cast(AndRHS))) { @@ -2582,8 +2582,7 @@ Instruction *InstCombiner::visitSetCondInst(SetCondInst &I) { Constant *Mask; if (CI->getType()->isUnsigned()) { unsigned TypeBits = CI->getType()->getPrimitiveSizeInBits(); - if (TypeBits != 64) - Val &= (1ULL << TypeBits)-1; + Val &= ~0ULL >> (64-TypeBits); Mask = ConstantUInt::get(CI->getType(), Val); } else { Mask = ConstantSInt::get(CI->getType(), Val); @@ -2985,9 +2984,6 @@ Instruction *InstCombiner::visitSetCondInstWithCastAndCast(SetCondInst &SCI) { if (SCI.getOpcode() == Instruction::SetNE) return ReplaceInstUsesWith(SCI, ConstantBool::True); - // SignBitSet - True if the top bit of the compared constant value is set. - bool SignBitSet = CI->getRawValue() & 1ULL << (DestBits-1); - // Evaluate the comparison for LT. Value *Result; if (DestTy->isSigned()) { @@ -3405,7 +3401,7 @@ Instruction *InstCombiner::visitCastInst(CastInst &CI) { CI.getType()->getPrimitiveSizeInBits()) { assert(CSrc->getType() != Type::ULongTy && "Cannot have type bigger than ulong!"); - uint64_t AndValue = (1ULL << CSrc->getType()->getPrimitiveSizeInBits())-1; + uint64_t AndValue = ~0ULL>>(64-CSrc->getType()->getPrimitiveSizeInBits()); Constant *AndOp = ConstantUInt::get(A->getType()->getUnsignedVersion(), AndValue); AndOp = ConstantExpr::getCast(AndOp, A->getType()); -- 2.34.1