Teach the SelectionDAG ISel how to turn ConstantPacked values into

constant nodes with vector types.  Also teach the asm printer how to print
ConstantPacked constant pool entries.  This allows us to generate altivec
code such as the following, which adds a vector constantto a packed float.

LCPI1_0:  <4 x float> < float 0.0e+0, float 0.0e+0, float 0.0e+0, float 1.0e+0 >
        .space  4
        .space  4
        .space  4
        .long   1065353216      ; float 1
        .text
        .align  4
        .globl  _foo
_foo:
        lis r2, ha16(LCPI1_0)
        la r2, lo16(LCPI1_0)(r2)
        li r4, 0
        lvx v0, r4, r2
        lvx v1, r4, r3
        vaddfp v0, v1, v0
        stvx v0, r4, r3
        blr

For the llvm code:

void %foo(<4 x float> * %a) {
entry:
  %tmp1 = load <4 x float> * %a;
  %tmp2 = add <4 x float> %tmp1, < float 0.0, float 0.0, float 0.0, float 1.0 >
  store <4 x float> %tmp2, <4 x float> *%a
  ret void
}


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24616 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nate Begeman 2005-12-06 06:18:55 +00:00
parent 4172b10ca1
commit 8cfa57b1b4
5 changed files with 66 additions and 5 deletions

View File

@ -67,6 +67,10 @@ namespace ISD {
GlobalAddress, FrameIndex, ConstantPool,
BasicBlock, ExternalSymbol, VALUETYPE, CONDCODE, Register,
// ConstantVec works like Constant or ConstantFP, except that it is not a
// leaf node. All operands are either Constant or ConstantFP nodes.
ConstantVec,
// TargetConstant - Like Constant, but the DAG does not do any folding or
// simplification of the constant. This is used by the DAG->DAG selector.
TargetConstant,

View File

@ -11,6 +11,7 @@
//
//===----------------------------------------------------------------------===//
#include "llvm/DerivedTypes.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/Constants.h"
#include "llvm/Module.h"
@ -326,6 +327,13 @@ void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
}
return;
}
} else if (const ConstantPacked *CP = dyn_cast<ConstantPacked>(CV)) {
const PackedType *PTy = CP->getType();
for (unsigned I = 0, E = PTy->getNumElements(); I < E; ++I)
EmitGlobalConstant(CP->getOperand(I));
return;
}
const Type *type = CV->getType();

View File

@ -690,6 +690,32 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
}
break;
}
case ISD::ConstantVec: {
// We assume that vector constants are not legal, and will be immediately
// spilled to the constant pool.
//
// FIXME: revisit this when we have some kind of mechanism by which targets
// can decided legality of vector constants, of which there may be very
// many.
//
// Create a ConstantPacked, and put it in the constant pool.
std::vector<Constant*> CV;
MVT::ValueType VT = Node->getValueType(0);
for (unsigned I = 0, E = Node->getNumOperands(); I < E; ++I) {
SDOperand OpN = Node->getOperand(I);
const Type* OpNTy = MVT::getTypeForValueType(OpN.getValueType());
if (MVT::isFloatingPoint(VT))
CV.push_back(ConstantFP::get(OpNTy,
cast<ConstantFPSDNode>(OpN)->getValue()));
else
CV.push_back(ConstantUInt::get(OpNTy,
cast<ConstantSDNode>(OpN)->getValue()));
}
Constant *CP = ConstantPacked::get(CV);
SDOperand CPIdx = DAG.getConstantPool(CP, Node->getValueType(0));
Result = DAG.getLoad(VT, DAG.getEntryNode(), CPIdx, DAG.getSrcValue(NULL));
break;
}
case ISD::TokenFactor:
if (Node->getNumOperands() == 2) {
bool Changed = false;

View File

@ -501,8 +501,6 @@ SDOperand SelectionDAG::getConstantFP(double Val, MVT::ValueType VT) {
return SDOperand(N, 0);
}
SDOperand SelectionDAG::getGlobalAddress(const GlobalValue *GV,
MVT::ValueType VT, int offset) {
SDNode *&N = GlobalValues[std::make_pair(GV, offset)];
@ -1837,6 +1835,7 @@ const char *SDNode::getOperationName(const SelectionDAG *G) const {
case ISD::Constant: return "Constant";
case ISD::TargetConstant: return "TargetConstant";
case ISD::ConstantFP: return "ConstantFP";
case ISD::ConstantVec: return "ConstantVec";
case ISD::GlobalAddress: return "GlobalAddress";
case ISD::TargetGlobalAddress: return "TargetGlobalAddress";
case ISD::FrameIndex: return "FrameIndex";

View File

@ -282,7 +282,8 @@ public:
SDOperand &N = NodeMap[V];
if (N.Val) return N;
MVT::ValueType VT = TLI.getValueType(V->getType());
const Type *VTy = V->getType();
MVT::ValueType VT = TLI.getValueType(VTy);
if (Constant *C = const_cast<Constant*>(dyn_cast<Constant>(V)))
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
visit(CE->getOpcode(), *CE);
@ -296,6 +297,30 @@ public:
return N = DAG.getNode(ISD::UNDEF, VT);
} else if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
return N = DAG.getConstantFP(CFP->getValue(), VT);
} else if (const PackedType *PTy = dyn_cast<PackedType>(VTy)) {
unsigned NumElements = PTy->getNumElements();
MVT::ValueType PVT = TLI.getValueType(PTy->getElementType());
MVT::ValueType TVT = MVT::getVectorType(PVT, NumElements);
// Now that we know the number and type of the elements, push a
// Constant or ConstantFP node onto the ops list for each element of
// the packed constant.
std::vector<SDOperand> Ops;
for (unsigned i = 0; i < NumElements; ++i) {
const Constant *CEl = C->getOperand(i);
if (MVT::isFloatingPoint(PVT))
Ops.push_back(DAG.getConstantFP(cast<ConstantFP>(CEl)->getValue(),
PVT));
else
Ops.push_back(
DAG.getConstant(cast<ConstantIntegral>(CEl)->getRawValue(),
PVT));
}
// Handle the case where we have a 1-element vector, in which
// case we want to immediately turn it into a scalar constant.
if (Ops.size() == 1)
return N = Ops[0];
return N = DAG.getNode(ISD::ConstantVec, TVT, Ops);
} else {
// Canonicalize all constant ints to be unsigned.
return N = DAG.getConstant(cast<ConstantIntegral>(C)->getRawValue(),VT);
@ -784,8 +809,7 @@ void SelectionDAGLowering::visitLoad(LoadInst &I) {
const Type *Ty = I.getType();
SDOperand L;
if (Type::PackedTyID == Ty->getTypeID()) {
const PackedType *PTy = cast<PackedType>(Ty);
if (const PackedType *PTy = dyn_cast<PackedType>(Ty)) {
unsigned NumElements = PTy->getNumElements();
MVT::ValueType PVT = TLI.getValueType(PTy->getElementType());
MVT::ValueType TVT = MVT::getVectorType(PVT, NumElements);