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For PR1205: 

APIntify several utility functions supporting logical operators and shift
operators.

Patch by Zhou Sheng.

llvm-svn: 35281
This commit is contained in:
Reid Spencer 2007-03-23 18:46:34 +00:00
parent ac8fe43024
commit 6274c72ee1
1 changed files with 39 additions and 37 deletions
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72
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
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@ -3666,17 +3666,14 @@ Instruction *InstCombiner::OptAndOp(Instruction *Op,
// Adding a one to a single bit bit-field should be turned into an XOR
// of the bit. First thing to check is to see if this AND is with a
// single bit constant.
uint64_t AndRHSV = cast<ConstantInt>(AndRHS)->getZExtValue();
// Clear bits that are not part of the constant.
AndRHSV &= AndRHS->getType()->getBitMask();
APInt AndRHSV(cast<ConstantInt>(AndRHS)->getValue());
// If there is only one bit set...
if (isOneBitSet(cast<ConstantInt>(AndRHS))) {
// Ok, at this point, we know that we are masking the result of the
// ADD down to exactly one bit. If the constant we are adding has
// no bits set below this bit, then we can eliminate the ADD.
uint64_t AddRHS = cast<ConstantInt>(OpRHS)->getZExtValue();
APInt AddRHS(cast<ConstantInt>(OpRHS)->getValue());
// Check to see if any bits below the one bit set in AndRHSV are set.
if ((AddRHS & (AndRHSV-1)) == 0) {
@ -3849,7 +3846,7 @@ Value *InstCombiner::FoldLogicalPlusAnd(Value *LHS, Value *RHS,
case Instruction::And:
if (ConstantExpr::getAnd(N, Mask) == Mask) {
// If the AndRHS is a power of two minus one (0+1+), this is simple.
if ((Mask->getZExtValue() & Mask->getZExtValue()+1) == 0)
if ((Mask->getValue() & Mask->getValue()+1) == 0)
break;
// Otherwise, if Mask is 0+1+0+, and if B is known to have the low 0+
@ -3857,8 +3854,9 @@ Value *InstCombiner::FoldLogicalPlusAnd(Value *LHS, Value *RHS,
// is all N is, ignore it.
unsigned MB, ME;
if (isRunOfOnes(Mask, MB, ME)) { // begin/end bit of run, inclusive
uint64_t Mask = cast<IntegerType>(RHS->getType())->getBitMask();
Mask >>= 64-MB+1;
uint32_t BitWidth = cast<IntegerType>(RHS->getType())->getBitWidth();
APInt Mask(APInt::getAllOnesValue(BitWidth));
Mask = APIntOps::lshr(Mask, BitWidth-MB+1);
if (MaskedValueIsZero(RHS, Mask))
break;
}
@ -3867,7 +3865,7 @@ Value *InstCombiner::FoldLogicalPlusAnd(Value *LHS, Value *RHS,
case Instruction::Or:
case Instruction::Xor:
// If the AndRHS is a power of two minus one (0+1+), and N&Mask == 0
if ((Mask->getZExtValue() & Mask->getZExtValue()+1) == 0 &&
if ((Mask->getValue() & Mask->getValue()+1) == 0 &&
ConstantExpr::getAnd(N, Mask)->isNullValue())
break;
return 0;
@ -6293,7 +6291,7 @@ Instruction *InstCombiner::commonShiftTransforms(BinaryOperator &I) {
// See if we can turn a signed shr into an unsigned shr.
if (I.isArithmeticShift()) {
if (MaskedValueIsZero(Op0,
1ULL << (I.getType()->getPrimitiveSizeInBits()-1))) {
APInt::getSignBit(I.getType()->getPrimitiveSizeInBits()))) {
return BinaryOperator::createLShr(Op0, Op1, I.getName());
}
}
@ -6310,16 +6308,16 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
// See if we can simplify any instructions used by the instruction whose sole
// purpose is to compute bits we don't care about.
uint64_t KnownZero, KnownOne;
if (SimplifyDemandedBits(&I, cast<IntegerType>(I.getType())->getBitMask(),
uint32_t TypeBits = Op0->getType()->getPrimitiveSizeInBits();
APInt KnownZero(TypeBits, 0), KnownOne(TypeBits, 0);
if (SimplifyDemandedBits(&I, APInt::getAllOnesValue(TypeBits),
KnownZero, KnownOne))
return &I;
// shl uint X, 32 = 0 and shr ubyte Y, 9 = 0, ... just don't eliminate shr
// of a signed value.
//
unsigned TypeBits = Op0->getType()->getPrimitiveSizeInBits();
if (Op1->getZExtValue() >= TypeBits) {
if (Op1->getZExtValue() >= TypeBits) { // shift amount always <= 32 bits
if (I.getOpcode() != Instruction::AShr)
return ReplaceInstUsesWith(I, Constant::getNullValue(Op0->getType()));
else {
@ -6462,8 +6460,8 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
// operation.
//
if (isValid && !isLeftShift && I.getOpcode() == Instruction::AShr) {
uint64_t Val = Op0C->getZExtValue();
isValid = ((Val & (1 << (TypeBits-1))) != 0) == highBitSet;
APInt Val(Op0C->getValue());
isValid = ((Val & APInt::getSignBit(TypeBits)) != 0) == highBitSet;
}
if (isValid) {
@ -6488,6 +6486,7 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
if (ShiftOp && isa<ConstantInt>(ShiftOp->getOperand(1))) {
ConstantInt *ShiftAmt1C = cast<ConstantInt>(ShiftOp->getOperand(1));
// shift amount always <= 32 bits
unsigned ShiftAmt1 = (unsigned)ShiftAmt1C->getZExtValue();
unsigned ShiftAmt2 = (unsigned)Op1->getZExtValue();
assert(ShiftAmt2 != 0 && "Should have been simplified earlier");
@ -6495,8 +6494,8 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
Value *X = ShiftOp->getOperand(0);
unsigned AmtSum = ShiftAmt1+ShiftAmt2; // Fold into one big shift.
if (AmtSum > I.getType()->getPrimitiveSizeInBits())
AmtSum = I.getType()->getPrimitiveSizeInBits();
if (AmtSum > TypeBits)
AmtSum = TypeBits;
const IntegerType *Ty = cast<IntegerType>(I.getType());
@ -6515,8 +6514,8 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
BinaryOperator::createAShr(X, ConstantInt::get(Ty, AmtSum));
InsertNewInstBefore(Shift, I);
uint64_t Mask = Ty->getBitMask() >> ShiftAmt2;
return BinaryOperator::createAnd(Shift, ConstantInt::get(Ty, Mask));
APInt Mask(APInt::getAllOnesValue(TypeBits).lshr(ShiftAmt2));
return BinaryOperator::createAnd(Shift, ConstantInt::get(Mask));
}
// Okay, if we get here, one shift must be left, and the other shift must be
@ -6524,13 +6523,13 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
if (ShiftAmt1 == ShiftAmt2) {
// If we have ((X >>? C) << C), turn this into X & (-1 << C).
if (I.getOpcode() == Instruction::Shl) {
uint64_t Mask = Ty->getBitMask() << ShiftAmt1;
return BinaryOperator::createAnd(X, ConstantInt::get(Ty, Mask));
APInt Mask(APInt::getAllOnesValue(TypeBits).shl(ShiftAmt1));
return BinaryOperator::createAnd(X, ConstantInt::get(Mask));
}
// If we have ((X << C) >>u C), turn this into X & (-1 >>u C).
if (I.getOpcode() == Instruction::LShr) {
uint64_t Mask = Ty->getBitMask() >> ShiftAmt1;
return BinaryOperator::createAnd(X, ConstantInt::get(Ty, Mask));
APInt Mask(APInt::getAllOnesValue(TypeBits).lshr(ShiftAmt1));
return BinaryOperator::createAnd(X, ConstantInt::get(Mask));
}
// We can simplify ((X << C) >>s C) into a trunc + sext.
// NOTE: we could do this for any C, but that would make 'unusual' integer
@ -6538,9 +6537,12 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
// generators.
const Type *SExtType = 0;
switch (Ty->getBitWidth() - ShiftAmt1) {
case 1 : SExtType = Type::Int1Ty; break;
case 8 : SExtType = Type::Int8Ty; break;
case 16: SExtType = Type::Int16Ty; break;
case 32: SExtType = Type::Int32Ty; break;
case 16 : SExtType = Type::Int16Ty; break;
case 32 : SExtType = Type::Int32Ty; break;
case 64 : SExtType = Type::Int64Ty; break;
case 128: SExtType = IntegerType::get(128); break;
default: break;
}
if (SExtType) {
@ -6560,8 +6562,8 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
BinaryOperator::createShl(X, ConstantInt::get(Ty, ShiftDiff));
InsertNewInstBefore(Shift, I);
uint64_t Mask = Ty->getBitMask() << ShiftAmt2;
return BinaryOperator::createAnd(Shift, ConstantInt::get(Ty, Mask));
APInt Mask(APInt::getAllOnesValue(TypeBits).shl(ShiftAmt2));
return BinaryOperator::createAnd(Shift, ConstantInt::get(Mask));
}
// (X << C1) >>u C2 --> X >>u (C2-C1) & (-1 >> C2)
@ -6571,8 +6573,8 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
BinaryOperator::createLShr(X, ConstantInt::get(Ty, ShiftDiff));
InsertNewInstBefore(Shift, I);
uint64_t Mask = Ty->getBitMask() >> ShiftAmt2;
return BinaryOperator::createAnd(Shift, ConstantInt::get(Ty, Mask));
APInt Mask(APInt::getAllOnesValue(TypeBits).lshr(ShiftAmt2));
return BinaryOperator::createAnd(Shift, ConstantInt::get(Mask));
}
// We can't handle (X << C1) >>s C2, it shifts arbitrary bits in.
@ -6589,8 +6591,8 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
ConstantInt::get(Ty, ShiftDiff));
InsertNewInstBefore(Shift, I);
uint64_t Mask = Ty->getBitMask() << ShiftAmt2;
return BinaryOperator::createAnd(Shift, ConstantInt::get(Ty, Mask));
APInt Mask(APInt::getAllOnesValue(TypeBits).shl(ShiftAmt2));
return BinaryOperator::createAnd(Shift, ConstantInt::get(Mask));
}
// (X << C1) >>u C2 --> X << (C1-C2) & (-1 >> C2)
@ -6600,8 +6602,8 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
BinaryOperator::createShl(X, ConstantInt::get(Ty, ShiftDiff));
InsertNewInstBefore(Shift, I);
uint64_t Mask = Ty->getBitMask() >> ShiftAmt2;
return BinaryOperator::createAnd(Shift, ConstantInt::get(Ty, Mask));
APInt Mask(APInt::getAllOnesValue(TypeBits).lshr(ShiftAmt2));
return BinaryOperator::createAnd(Shift, ConstantInt::get(Mask));
}
// We can't handle (X << C1) >>a C2, it shifts arbitrary bits in.
@ -8191,7 +8193,7 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) {
(ParamTy->isInteger() && ActTy->isInteger() &&
ParamTy->getPrimitiveSizeInBits() >= ActTy->getPrimitiveSizeInBits()) ||
(c && ParamTy->getPrimitiveSizeInBits() >= ActTy->getPrimitiveSizeInBits()
&& c->getSExtValue() > 0);
&& c->getValue().isPositive());
if (Callee->isDeclaration() && !isConvertible) return false;
}