Combine PPC's GetConstantBuildVectorBits and isConstantSplat functions to a new

method in a BuildVectorSDNode "pseudo-class".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65747 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bob Wilson 2009-03-01 01:13:55 +00:00
parent f6f0bdfec3
commit a27ea9e89f
3 changed files with 114 additions and 106 deletions

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@ -1929,6 +1929,24 @@ public:
}
};
/// BuildVectorSDNode - A "pseudo-class" with methods for operating on
/// BUILD_VECTORs.
class BuildVectorSDNode : public SDNode {
public:
/// isConstantSplat - check if this is a constant splat, and if so, return
/// the splat element value in SplatBits. Any undefined bits in that value
/// are set to zero, and the corresponding bits in the SplatUndef mask are
/// set. The SplatSize value is set to the splat element size in bytes.
/// HasAnyUndefs is set to true if any bits in the vector are undefined.
bool isConstantSplat(unsigned &SplatBits, unsigned &SplatUndef,
unsigned &SplatSize, bool &HasAnyUndefs);
static inline bool classof(const BuildVectorSDNode *) { return true; }
static inline bool classof(const SDNode *N) {
return N->getOpcode() == ISD::BUILD_VECTOR;
}
};
/// SrcValueSDNode - An SDNode that holds an arbitrary LLVM IR Value. This is
/// used when the SelectionDAG needs to make a simple reference to something
/// in the LLVM IR representation.

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@ -5554,3 +5554,94 @@ const Type *ConstantPoolSDNode::getType() const {
return Val.MachineCPVal->getType();
return Val.ConstVal->getType();
}
// If this is a splat (repetition) of a value across the whole vector, return
// the smallest size that splats it. For example, "0x01010101010101..." is a
// splat of 0x01, 0x0101, and 0x01010101. We return SplatBits = 0x01 and
// SplatSize = 1 byte.
bool BuildVectorSDNode::isConstantSplat(unsigned &SplatBits,
unsigned &SplatUndef,
unsigned &SplatSize,
bool &HasAnyUndefs) {
uint64_t Bits128[2];
uint64_t Undef128[2];
// If this is a vector of constants or undefs, get the bits. A bit in
// UndefBits is set if the corresponding element of the vector is an
// ISD::UNDEF value. For undefs, the corresponding VectorBits values are
// zero.
// Start with zero'd results.
Bits128[0] = Bits128[1] = Undef128[0] = Undef128[1] = 0;
unsigned EltBitSize = getOperand(0).getValueType().getSizeInBits();
for (unsigned i = 0, e = getNumOperands(); i != e; ++i) {
SDValue OpVal = getOperand(i);
unsigned PartNo = i >= e/2; // In the upper 128 bits?
unsigned SlotNo = e/2 - (i & (e/2-1))-1; // Which subpiece of the uint64_t.
uint64_t EltBits = 0;
if (OpVal.getOpcode() == ISD::UNDEF) {
uint64_t EltUndefBits = ~0U >> (32-EltBitSize);
Undef128[PartNo] |= EltUndefBits << (SlotNo*EltBitSize);
continue;
} else if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(OpVal)) {
EltBits = CN->getZExtValue() & (~0U >> (32-EltBitSize));
} else if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(OpVal)) {
assert(CN->getValueType(0) == MVT::f32 &&
"Only one legal FP vector type!");
EltBits = FloatToBits(CN->getValueAPF().convertToFloat());
} else {
// Nonconstant element.
return false;
}
Bits128[PartNo] |= EltBits << (SlotNo*EltBitSize);
}
// Don't let undefs prevent splats from matching. See if the top 64-bits are
// the same as the lower 64-bits, ignoring undefs.
if ((Bits128[0] & ~Undef128[1]) != (Bits128[1] & ~Undef128[0]))
return false; // Can't be a splat if two pieces don't match.
uint64_t Bits64 = Bits128[0] | Bits128[1];
uint64_t Undef64 = Undef128[0] & Undef128[1];
// Check that the top 32-bits are the same as the lower 32-bits, ignoring
// undefs.
if ((Bits64 & (~Undef64 >> 32)) != ((Bits64 >> 32) & ~Undef64))
return false; // Can't be a splat if two pieces don't match.
HasAnyUndefs = (Undef128[0] | Undef128[1]) != 0;
uint32_t Bits32 = uint32_t(Bits64) | uint32_t(Bits64 >> 32);
uint32_t Undef32 = uint32_t(Undef64) & uint32_t(Undef64 >> 32);
// If the top 16-bits are different than the lower 16-bits, ignoring
// undefs, we have an i32 splat.
if ((Bits32 & (~Undef32 >> 16)) != ((Bits32 >> 16) & ~Undef32)) {
SplatBits = Bits32;
SplatUndef = Undef32;
SplatSize = 4;
return true;
}
uint16_t Bits16 = uint16_t(Bits32) | uint16_t(Bits32 >> 16);
uint16_t Undef16 = uint16_t(Undef32) & uint16_t(Undef32 >> 16);
// If the top 8-bits are different than the lower 8-bits, ignoring
// undefs, we have an i16 splat.
if ((Bits16 & (uint16_t(~Undef16) >> 8)) != ((Bits16 >> 8) & ~Undef16)) {
SplatBits = Bits16;
SplatUndef = Undef16;
SplatSize = 2;
return true;
}
// Otherwise, we have an 8-bit splat.
SplatBits = uint8_t(Bits16) | uint8_t(Bits16 >> 8);
SplatUndef = uint8_t(Undef16) & uint8_t(Undef16 >> 8);
SplatSize = 1;
return true;
}

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@ -3093,100 +3093,6 @@ SDValue PPCTargetLowering::LowerSRA_PARTS(SDValue Op, SelectionDAG &DAG) {
// Vector related lowering.
//
// If this is a vector of constants or undefs, get the bits. A bit in
// UndefBits is set if the corresponding element of the vector is an
// ISD::UNDEF value. For undefs, the corresponding VectorBits values are
// zero. Return true if this is not an array of constants, false if it is.
//
static bool GetConstantBuildVectorBits(SDNode *BV, uint64_t VectorBits[2],
uint64_t UndefBits[2]) {
// Start with zero'd results.
VectorBits[0] = VectorBits[1] = UndefBits[0] = UndefBits[1] = 0;
unsigned EltBitSize = BV->getOperand(0).getValueType().getSizeInBits();
for (unsigned i = 0, e = BV->getNumOperands(); i != e; ++i) {
SDValue OpVal = BV->getOperand(i);
unsigned PartNo = i >= e/2; // In the upper 128 bits?
unsigned SlotNo = e/2 - (i & (e/2-1))-1; // Which subpiece of the uint64_t.
uint64_t EltBits = 0;
if (OpVal.getOpcode() == ISD::UNDEF) {
uint64_t EltUndefBits = ~0U >> (32-EltBitSize);
UndefBits[PartNo] |= EltUndefBits << (SlotNo*EltBitSize);
continue;
} else if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(OpVal)) {
EltBits = CN->getZExtValue() & (~0U >> (32-EltBitSize));
} else if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(OpVal)) {
assert(CN->getValueType(0) == MVT::f32 &&
"Only one legal FP vector type!");
EltBits = FloatToBits(CN->getValueAPF().convertToFloat());
} else {
// Nonconstant element.
return true;
}
VectorBits[PartNo] |= EltBits << (SlotNo*EltBitSize);
}
//printf("%llx %llx %llx %llx\n",
// VectorBits[0], VectorBits[1], UndefBits[0], UndefBits[1]);
return false;
}
// If this is a splat (repetition) of a value across the whole vector, return
// the smallest size that splats it. For example, "0x01010101010101..." is a
// splat of 0x01, 0x0101, and 0x01010101. We return SplatBits = 0x01 and
// SplatSize = 1 byte.
static bool isConstantSplat(const uint64_t Bits128[2],
const uint64_t Undef128[2],
unsigned &SplatBits, unsigned &SplatUndef,
unsigned &SplatSize) {
// Don't let undefs prevent splats from matching. See if the top 64-bits are
// the same as the lower 64-bits, ignoring undefs.
if ((Bits128[0] & ~Undef128[1]) != (Bits128[1] & ~Undef128[0]))
return false; // Can't be a splat if two pieces don't match.
uint64_t Bits64 = Bits128[0] | Bits128[1];
uint64_t Undef64 = Undef128[0] & Undef128[1];
// Check that the top 32-bits are the same as the lower 32-bits, ignoring
// undefs.
if ((Bits64 & (~Undef64 >> 32)) != ((Bits64 >> 32) & ~Undef64))
return false; // Can't be a splat if two pieces don't match.
uint32_t Bits32 = uint32_t(Bits64) | uint32_t(Bits64 >> 32);
uint32_t Undef32 = uint32_t(Undef64) & uint32_t(Undef64 >> 32);
// If the top 16-bits are different than the lower 16-bits, ignoring
// undefs, we have an i32 splat.
if ((Bits32 & (~Undef32 >> 16)) != ((Bits32 >> 16) & ~Undef32)) {
SplatBits = Bits32;
SplatUndef = Undef32;
SplatSize = 4;
return true;
}
uint16_t Bits16 = uint16_t(Bits32) | uint16_t(Bits32 >> 16);
uint16_t Undef16 = uint16_t(Undef32) & uint16_t(Undef32 >> 16);
// If the top 8-bits are different than the lower 8-bits, ignoring
// undefs, we have an i16 splat.
if ((Bits16 & (uint16_t(~Undef16) >> 8)) != ((Bits16 >> 8) & ~Undef16)) {
SplatBits = Bits16;
SplatUndef = Undef16;
SplatSize = 2;
return true;
}
// Otherwise, we have an 8-bit splat.
SplatBits = uint8_t(Bits16) | uint8_t(Bits16 >> 8);
SplatUndef = uint8_t(Undef16) & uint8_t(Undef16 >> 8);
SplatSize = 1;
return true;
}
/// BuildSplatI - Build a canonical splati of Val with an element size of
/// SplatSize. Cast the result to VT.
static SDValue BuildSplatI(int Val, unsigned SplatSize, MVT VT,
@ -3256,25 +3162,18 @@ static SDValue BuildVSLDOI(SDValue LHS, SDValue RHS, unsigned Amt,
// selects to a single instruction, return Op. Otherwise, if we can codegen
// this case more efficiently than a constant pool load, lower it to the
// sequence of ops that should be used.
SDValue PPCTargetLowering::LowerBUILD_VECTOR(SDValue Op,
SelectionDAG &DAG) {
// If this is a vector of constants or undefs, get the bits. A bit in
// UndefBits is set if the corresponding element of the vector is an
// ISD::UNDEF value. For undefs, the corresponding VectorBits values are
// zero.
uint64_t VectorBits[2];
uint64_t UndefBits[2];
SDValue PPCTargetLowering::LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) {
DebugLoc dl = Op.getDebugLoc();
if (GetConstantBuildVectorBits(Op.getNode(), VectorBits, UndefBits))
return SDValue(); // Not a constant vector.
BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
assert(BVN != 0 && "Expected a BuildVectorSDNode in LowerBUILD_VECTOR");
// If this is a splat (repetition) of a value across the whole vector, return
// the smallest size that splats it. For example, "0x01010101010101..." is a
// splat of 0x01, 0x0101, and 0x01010101. We return SplatBits = 0x01 and
// SplatSize = 1 byte.
unsigned SplatBits, SplatUndef, SplatSize;
if (isConstantSplat(VectorBits, UndefBits, SplatBits, SplatUndef, SplatSize)){
bool HasAnyUndefs = (UndefBits[0] | UndefBits[1]) != 0;
bool HasAnyUndefs;
if (BVN->isConstantSplat(SplatBits, SplatUndef, SplatSize, HasAnyUndefs)) {
// First, handle single instruction cases.