Add an assertion to the form of SelectionDAG::getConstant that takes

a uint64_t to verify that the value is in range for the given type,
to help catch accidental overflow. Fix a few places that relied on
getConstant implicitly truncating the value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63128 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2009-01-27 20:39:34 +00:00
parent d3f184906d
commit ce9bc12c6f
4 changed files with 18 additions and 9 deletions

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@ -444,8 +444,11 @@ namespace llvm {
/// getIntegerVTBitMask - Return an integer with 1's every place there are
/// bits in the specified integer value type. FIXME: Should return an apint.
uint64_t getIntegerVTBitMask() const {
assert(isInteger() && !isVector() && "Only applies to int scalars!");
return ~uint64_t(0UL) >> (64-getSizeInBits());
assert(isInteger() && "Only applies to integers!");
MVT EltVT = isVector() ? getVectorElementType() : *this;
assert(EltVT.getSizeInBits() <= 64 &&
"getIntegerVTBitMask doesn't use APInt!");
return ~uint64_t(0UL) >> (64-EltVT.getSizeInBits());
}
/// getIntegerVTSignBit - Return an integer with a 1 in the position of the

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@ -2434,11 +2434,12 @@ SDValue DAGCombiner::visitSHL(SDNode *N) {
if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
MVT TruncVT = N1.getValueType();
SDValue N100 = N1.getOperand(0).getOperand(0);
uint64_t TruncC = TruncVT.getIntegerVTBitMask() &
N101C->getZExtValue();
return DAG.getNode(ISD::SHL, VT, N0,
DAG.getNode(ISD::AND, TruncVT,
DAG.getNode(ISD::TRUNCATE, TruncVT, N100),
DAG.getConstant(N101C->getZExtValue(),
TruncVT)));
DAG.getConstant(TruncC, TruncVT)));
}
}
@ -2561,11 +2562,12 @@ SDValue DAGCombiner::visitSRA(SDNode *N) {
if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
MVT TruncVT = N1.getValueType();
SDValue N100 = N1.getOperand(0).getOperand(0);
uint64_t TruncC = TruncVT.getIntegerVTBitMask() &
N101C->getZExtValue();
return DAG.getNode(ISD::SRA, VT, N0,
DAG.getNode(ISD::AND, TruncVT,
DAG.getNode(ISD::TRUNCATE, TruncVT, N100),
DAG.getConstant(N101C->getZExtValue(),
TruncVT)));
DAG.getConstant(TruncC, TruncVT)));
}
}
@ -2678,11 +2680,12 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
if (ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N101)) {
MVT TruncVT = N1.getValueType();
SDValue N100 = N1.getOperand(0).getOperand(0);
uint64_t TruncC = TruncVT.getIntegerVTBitMask() &
N101C->getZExtValue();
return DAG.getNode(ISD::SRL, VT, N0,
DAG.getNode(ISD::AND, TruncVT,
DAG.getNode(ISD::TRUNCATE, TruncVT, N100),
DAG.getConstant(N101C->getZExtValue(),
TruncVT)));
DAG.getConstant(TruncC, TruncVT)));
}
}

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@ -6293,7 +6293,7 @@ SDValue SelectionDAGLegalize::ExpandBitCount(unsigned Opc, SDValue Op) {
unsigned len = VT.getSizeInBits();
for (unsigned i = 0; (1U << i) <= (len / 2); ++i) {
//x = (x & mask[i][len/8]) + (x >> (1 << i) & mask[i][len/8])
SDValue Tmp2 = DAG.getConstant(mask[i], VT);
SDValue Tmp2 = DAG.getConstant(VT.getIntegerVTBitMask() & mask[i], VT);
SDValue Tmp3 = DAG.getConstant(1ULL << i, ShVT);
Op = DAG.getNode(ISD::ADD, VT, DAG.getNode(ISD::AND, VT, Op, Tmp2),
DAG.getNode(ISD::AND, VT,

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@ -848,6 +848,9 @@ SDValue SelectionDAG::getNOT(SDValue Val, MVT VT) {
SDValue SelectionDAG::getConstant(uint64_t Val, MVT VT, bool isT) {
MVT EltVT = VT.isVector() ? VT.getVectorElementType() : VT;
assert((EltVT.getSizeInBits() >= 64 ||
(uint64_t)((int64_t)Val >> EltVT.getSizeInBits()) + 1 < 2) &&
"getConstant with a uint64_t value that doesn't fit in the type!");
return getConstant(APInt(EltVT.getSizeInBits(), Val), VT, isT);
}