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Factor replacement of stores of FP constants into new function 

llvm-svn: 248168
This commit is contained in:
Matt Arsenault 2015-09-21 15:59:43 +00:00
parent 30ad1a3c01
commit a30ddb6524
1 changed files with 104 additions and 72 deletions
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176
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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@ -301,6 +301,7 @@ namespace {
SDValue visitLOAD(SDNode *N);
SDValue replaceStoreChain(StoreSDNode *ST, SDValue BetterChain);
SDValue replaceStoreOfFPConstant(StoreSDNode *ST);
SDValue visitSTORE(SDNode *N);
SDValue visitINSERT_VECTOR_ELT(SDNode *N);
@ -11361,6 +11362,102 @@ SDValue DAGCombiner::replaceStoreChain(StoreSDNode *ST, SDValue BetterChain) {
return CombineTo(ST, Token, false);
}
SDValue DAGCombiner::replaceStoreOfFPConstant(StoreSDNode *ST) {
SDValue Value = ST->getValue();
if (Value.getOpcode() == ISD::TargetConstantFP)
return SDValue();
SDLoc DL(ST);
SDValue Chain = ST->getChain();
SDValue Ptr = ST->getBasePtr();
const ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Value);
// NOTE: If the original store is volatile, this transform must not increase
// the number of stores. For example, on x86-32 an f64 can be stored in one
// processor operation but an i64 (which is not legal) requires two. So the
// transform should not be done in this case.
SDValue Tmp;
switch (CFP->getSimpleValueType(0).SimpleTy) {
default:
llvm_unreachable("Unknown FP type");
case MVT::f16: // We don't do this for these yet.
case MVT::f80:
case MVT::f128:
case MVT::ppcf128:
return SDValue();
case MVT::f32:
if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
;
Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
bitcastToAPInt().getZExtValue(), SDLoc(CFP),
MVT::i32);
SDValue NewSt = DAG.getStore(Chain, DL, Tmp,
Ptr, ST->getMemOperand());
dbgs() << "Replacing FP constant: ";
Value->dump(&DAG);
if (cast<StoreSDNode>(NewSt)->getMemoryVT() != MVT::i32) {
dbgs() << "Different memoryvt\n";
} else {
dbgs() << "same memoryvt\n";
}
return NewSt;
}
return SDValue();
case MVT::f64:
if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
!ST->isVolatile()) ||
TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
;
Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
getZExtValue(), SDLoc(CFP), MVT::i64);
return DAG.getStore(Chain, DL, Tmp,
Ptr, ST->getMemOperand());
}
if (!ST->isVolatile() &&
TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
// Many FP stores are not made apparent until after legalize, e.g. for
// argument passing. Since this is so common, custom legalize the
// 64-bit integer store into two 32-bit stores.
uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, SDLoc(CFP), MVT::i32);
SDValue Hi = DAG.getConstant(Val >> 32, SDLoc(CFP), MVT::i32);
if (DAG.getDataLayout().isBigEndian())
std::swap(Lo, Hi);
unsigned Alignment = ST->getAlignment();
bool isVolatile = ST->isVolatile();
bool isNonTemporal = ST->isNonTemporal();
AAMDNodes AAInfo = ST->getAAInfo();
SDValue St0 = DAG.getStore(Chain, DL, Lo,
Ptr, ST->getPointerInfo(),
isVolatile, isNonTemporal,
ST->getAlignment(), AAInfo);
Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
DAG.getConstant(4, DL, Ptr.getValueType()));
Alignment = MinAlign(Alignment, 4U);
SDValue St1 = DAG.getStore(Chain, DL, Hi,
Ptr, ST->getPointerInfo().getWithOffset(4),
isVolatile, isNonTemporal,
Alignment, AAInfo);
return DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
St0, St1);
}
return SDValue();
}
}
SDValue DAGCombiner::visitSTORE(SDNode *N) {
StoreSDNode *ST = cast<StoreSDNode>(N);
SDValue Chain = ST->getChain();
@ -11389,78 +11486,13 @@ SDValue DAGCombiner::visitSTORE(SDNode *N) {
return Chain;
// Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(Value)) {
// NOTE: If the original store is volatile, this transform must not increase
// the number of stores. For example, on x86-32 an f64 can be stored in one
// processor operation but an i64 (which is not legal) requires two. So the
// transform should not be done in this case.
if (Value.getOpcode() != ISD::TargetConstantFP) {
SDValue Tmp;
switch (CFP->getSimpleValueType(0).SimpleTy) {
default: llvm_unreachable("Unknown FP type");
case MVT::f16: // We don't do this for these yet.
case MVT::f80:
case MVT::f128:
case MVT::ppcf128:
break;
case MVT::f32:
if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
;
Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
bitcastToAPInt().getZExtValue(), SDLoc(CFP),
MVT::i32);
return DAG.getStore(Chain, SDLoc(N), Tmp,
Ptr, ST->getMemOperand());
}
break;
case MVT::f64:
if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
!ST->isVolatile()) ||
TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
;
Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
getZExtValue(), SDLoc(CFP), MVT::i64);
return DAG.getStore(Chain, SDLoc(N), Tmp,
Ptr, ST->getMemOperand());
}
if (!ST->isVolatile() &&
TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
// Many FP stores are not made apparent until after legalize, e.g. for
// argument passing. Since this is so common, custom legalize the
// 64-bit integer store into two 32-bit stores.
uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, SDLoc(CFP), MVT::i32);
SDValue Hi = DAG.getConstant(Val >> 32, SDLoc(CFP), MVT::i32);
if (DAG.getDataLayout().isBigEndian())
std::swap(Lo, Hi);
unsigned Alignment = ST->getAlignment();
bool isVolatile = ST->isVolatile();
bool isNonTemporal = ST->isNonTemporal();
AAMDNodes AAInfo = ST->getAAInfo();
SDLoc DL(N);
SDValue St0 = DAG.getStore(Chain, SDLoc(ST), Lo,
Ptr, ST->getPointerInfo(),
isVolatile, isNonTemporal,
ST->getAlignment(), AAInfo);
Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
DAG.getConstant(4, DL, Ptr.getValueType()));
Alignment = MinAlign(Alignment, 4U);
SDValue St1 = DAG.getStore(Chain, SDLoc(ST), Hi,
Ptr, ST->getPointerInfo().getWithOffset(4),
isVolatile, isNonTemporal,
Alignment, AAInfo);
return DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
St0, St1);
}
break;
}
}
//
// Make sure to do this only after attempting to merge stores in order to
// avoid changing the types of some subset of stores due to visit order,
// preventing their merging.
if (isa<ConstantFPSDNode>(Value)) {
if (SDValue NewSt = replaceStoreOfFPConstant(ST))
return NewSt;
}
// Try to infer better alignment information than the store already has.