}
#ifndef NDEBUG
-/// PrintOps - Print out the expression identified in the Ops list.
+/// Print out the expression identified in the Ops list.
///
static void PrintOps(Instruction *I, const SmallVectorImpl<ValueEntry> &Ops) {
Module *M = I->getParent()->getParent()->getParent();
// Public interface to the Reassociate pass
FunctionPass *llvm::createReassociatePass() { return new Reassociate(); }
-/// isReassociableOp - Return true if V is an instruction of the specified
-/// opcode and if it only has one use.
+/// Return true if V is an instruction of the specified opcode and if it
+/// only has one use.
static BinaryOperator *isReassociableOp(Value *V, unsigned Opcode) {
if (V->hasOneUse() && isa<Instruction>(V) &&
cast<Instruction>(V)->getOpcode() == Opcode &&
}
}
-/// LowerNegateToMultiply - Replace 0-X with X*-1.
-///
+/// Replace 0-X with X*-1.
static BinaryOperator *LowerNegateToMultiply(Instruction *Neg) {
Type *Ty = Neg->getType();
Constant *NegOne = Ty->isIntOrIntVectorTy() ?
return Res;
}
-/// CarmichaelShift - Returns k such that lambda(2^Bitwidth) = 2^k, where lambda
-/// is the Carmichael function. This means that x^(2^k) === 1 mod 2^Bitwidth for
+/// Returns k such that lambda(2^Bitwidth) = 2^k, where lambda is the Carmichael
+/// function. This means that x^(2^k) === 1 mod 2^Bitwidth for
/// every odd x, i.e. x^(2^k) = 1 for every odd x in Bitwidth-bit arithmetic.
/// Note that 0 <= k < Bitwidth, and if Bitwidth > 3 then x^(2^k) = 0 for every
/// even x in Bitwidth-bit arithmetic.
return Bitwidth - 2;
}
-/// IncorporateWeight - Add the extra weight 'RHS' to the existing weight 'LHS',
+/// Add the extra weight 'RHS' to the existing weight 'LHS',
/// reducing the combined weight using any special properties of the operation.
/// The existing weight LHS represents the computation X op X op ... op X where
/// X occurs LHS times. The combined weight represents X op X op ... op X with
typedef std::pair<Value*, APInt> RepeatedValue;
-/// LinearizeExprTree - Given an associative binary expression, return the leaf
+/// Given an associative binary expression, return the leaf
/// nodes in Ops along with their weights (how many times the leaf occurs). The
/// original expression is the same as
/// (Ops[0].first op Ops[0].first op ... Ops[0].first) <- Ops[0].second times
return Changed;
}
-// RewriteExprTree - Now that the operands for this expression tree are
-// linearized and optimized, emit them in-order.
+/// Now that the operands for this expression tree are
+/// linearized and optimized, emit them in-order.
void Reassociate::RewriteExprTree(BinaryOperator *I,
SmallVectorImpl<ValueEntry> &Ops) {
assert(Ops.size() > 1 && "Single values should be used directly!");
RedoInsts.insert(NodesToRewrite[i]);
}
-/// NegateValue - Insert instructions before the instruction pointed to by BI,
+/// Insert instructions before the instruction pointed to by BI,
/// that computes the negative version of the value specified. The negative
/// version of the value is returned, and BI is left pointing at the instruction
/// that should be processed next by the reassociation pass.
return CreateNeg(V, V->getName() + ".neg", BI, BI);
}
-/// ShouldBreakUpSubtract - Return true if we should break up this subtract of
-/// X-Y into (X + -Y).
+/// Return true if we should break up this subtract of X-Y into (X + -Y).
static bool ShouldBreakUpSubtract(Instruction *Sub) {
// If this is a negation, we can't split it up!
if (BinaryOperator::isNeg(Sub) || BinaryOperator::isFNeg(Sub))
return false;
}
-/// BreakUpSubtract - If we have (X-Y), and if either X is an add, or if this is
-/// only used by an add, transform this into (X+(0-Y)) to promote better
-/// reassociation.
+/// If we have (X-Y), and if either X is an add, or if this is only used by an
+/// add, transform this into (X+(0-Y)) to promote better reassociation.
static BinaryOperator *BreakUpSubtract(Instruction *Sub) {
// Convert a subtract into an add and a neg instruction. This allows sub
// instructions to be commuted with other add instructions.
return New;
}
-/// ConvertShiftToMul - If this is a shift of a reassociable multiply or is used
-/// by one, change this into a multiply by a constant to assist with further
-/// reassociation.
+/// If this is a shift of a reassociable multiply or is used by one, change
+/// this into a multiply by a constant to assist with further reassociation.
static BinaryOperator *ConvertShiftToMul(Instruction *Shl) {
Constant *MulCst = ConstantInt::get(Shl->getType(), 1);
MulCst = ConstantExpr::getShl(MulCst, cast<Constant>(Shl->getOperand(1)));
return Mul;
}
-/// FindInOperandList - Scan backwards and forwards among values with the same
-/// rank as element i to see if X exists. If X does not exist, return i. This
-/// is useful when scanning for 'x' when we see '-x' because they both get the
-/// same rank.
+/// Scan backwards and forwards among values with the same rank as element i
+/// to see if X exists. If X does not exist, return i. This is useful when
+/// scanning for 'x' when we see '-x' because they both get the same rank.
static unsigned FindInOperandList(SmallVectorImpl<ValueEntry> &Ops, unsigned i,
Value *X) {
unsigned XRank = Ops[i].Rank;
return i;
}
-/// EmitAddTreeOfValues - Emit a tree of add instructions, summing Ops together
+/// Emit a tree of add instructions, summing Ops together
/// and returning the result. Insert the tree before I.
static Value *EmitAddTreeOfValues(Instruction *I,
SmallVectorImpl<WeakVH> &Ops){
return CreateAdd(V2, V1, "tmp", I, I);
}
-/// RemoveFactorFromExpression - If V is an expression tree that is a
-/// multiplication sequence, and if this sequence contains a multiply by Factor,
+/// If V is an expression tree that is a multiplication sequence,
+/// and if this sequence contains a multiply by Factor,
/// remove Factor from the tree and return the new tree.
Value *Reassociate::RemoveFactorFromExpression(Value *V, Value *Factor) {
BinaryOperator *BO = isReassociableOp(V, Instruction::Mul, Instruction::FMul);
return V;
}
-/// FindSingleUseMultiplyFactors - If V is a single-use multiply, recursively
-/// add its operands as factors, otherwise add V to the list of factors.
+/// If V is a single-use multiply, recursively add its operands as factors,
+/// otherwise add V to the list of factors.
///
/// Ops is the top-level list of add operands we're trying to factor.
static void FindSingleUseMultiplyFactors(Value *V,
FindSingleUseMultiplyFactors(BO->getOperand(0), Factors, Ops);
}
-/// OptimizeAndOrXor - Optimize a series of operands to an 'and', 'or', or 'xor'
-/// instruction. This optimizes based on identities. If it can be reduced to
-/// a single Value, it is returned, otherwise the Ops list is mutated as
-/// necessary.
+/// Optimize a series of operands to an 'and', 'or', or 'xor' instruction.
+/// This optimizes based on identities. If it can be reduced to a single Value,
+/// it is returned, otherwise the Ops list is mutated as necessary.
static Value *OptimizeAndOrXor(unsigned Opcode,
SmallVectorImpl<ValueEntry> &Ops) {
// Scan the operand lists looking for X and ~X pairs, along with X,X pairs.
return nullptr;
}
-/// OptimizeAdd - Optimize a series of operands to an 'add' instruction. This
+/// Optimize a series of operands to an 'add' instruction. This
/// optimizes based on identities. If it can be reduced to a single Value, it
/// is returned, otherwise the Ops list is mutated as necessary.
Value *Reassociate::OptimizeAdd(Instruction *I,
return nullptr;
}
-/// EraseInst - Zap the given instruction, adding interesting operands to the
-/// work list.
+/// Zap the given instruction, adding interesting operands to the work list.
void Reassociate::EraseInst(Instruction *I) {
assert(isInstructionTriviallyDead(I) && "Trivially dead instructions only!");
SmallVector<Value*, 8> Ops(I->op_begin(), I->op_end());
return NI;
}
-/// OptimizeInst - Inspect and optimize the given instruction. Note that erasing
+/// Inspect and optimize the given instruction. Note that erasing
/// instructions is not allowed.
void Reassociate::OptimizeInst(Instruction *I) {
// Only consider operations that we understand.
// the vector.
std::stable_sort(Ops.begin(), Ops.end());
- // OptimizeExpression - Now that we have the expression tree in a convenient
+ // Now that we have the expression tree in a convenient
// sorted form, optimize it globally if possible.
if (Value *V = OptimizeExpression(I, Ops)) {
if (V == I)
projects / oota-llvm.git / commitdiff