[llvm-commits] [llvm] r47554 - /llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
Evan Cheng
evan.cheng at apple.com
Mon Feb 25 11:52:31 PST 2008
On Feb 25, 2008, at 11:20 AM, Dale Johannesen wrote:
> Author: johannes
> Date: Mon Feb 25 13:20:14 2008
> New Revision: 47554
>
> URL: http://llvm.org/viewvc/llvm-project?rev=47554&view=rev
> Log:
> Expand removal of MMX memory copies to allow 1 level
> of TokenFactor underneath chain (seems to be enough)
>
>
> Modified:
> llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
>
> Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=47554&r1=47553&r2=47554&view=diff
>
> =
> =
> =
> =
> =
> =
> =
> =
> ======================================================================
> --- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
> +++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Feb 25
> 13:20:14 2008
> @@ -5878,50 +5878,86 @@
> const X86Subtarget *Subtarget) {
> // Turn load->store of MMX types into GPR load/stores. This
> avoids clobbering
> // the FP state in cases where an emms may be missing.
> + // A preferable solution to the general problem is to figure out
> the right
> + // places to insert EMMS. This qualifies as a quick hack.
> if (MVT::isVector(St->getValue().getValueType()) &&
> MVT::getSizeInBits(St->getValue().getValueType()) == 64 &&
> - // Must be a store of a load.
> - isa<LoadSDNode>(St->getChain()) &&
> - St->getChain().Val == St->getValue().Val &&
> - St->getValue().hasOneUse() && St->getChain().hasOneUse() &&
> - !St->isVolatile() && !cast<LoadSDNode>(St->getChain())-
> >isVolatile()) {
> - LoadSDNode *Ld = cast<LoadSDNode>(St->getChain());
> -
> - // If we are a 64-bit capable x86, lower to a single movq load/
> store pair.
> - if (Subtarget->is64Bit()) {
> - SDOperand NewLd = DAG.getLoad(MVT::i64, Ld->getChain(), Ld-
> >getBasePtr(),
> - Ld->getSrcValue(), Ld-
> >getSrcValueOffset(),
> - Ld->isVolatile(), Ld-
> >getAlignment());
> - return DAG.getStore(NewLd.getValue(1), NewLd, St->getBasePtr(),
> + isa<LoadSDNode>(St->getValue()) &&
> + !cast<LoadSDNode>(St->getValue())->isVolatile() &&
> + St->getChain().hasOneUse() && !St->isVolatile()) {
> + LoadSDNode *Ld = 0;
> + int TokenFactorIndex = -1;
> + SmallVector<SDOperand, 8> Ops;
> + SDNode* ChainVal = St->getChain().Val;
> + // Must be a store of a load. We currently handle two cases:
> the load
> + // is a direct child, and it's under an intervening
> TokenFactor. It is
> + // possible to dig deeper under nested TokenFactors.
> + if (ChainVal == St->getValue().Val)
> + Ld = cast<LoadSDNode>(St->getChain());
> + else if (St->getValue().hasOneUse() &&
> + ChainVal->getOpcode() == ISD::TokenFactor) {
> + for (unsigned i=0, e = ChainVal->getNumOperands(); i != e; +
> +i) {
> + if (ChainVal->getOperand(i).Val == St->getValue().Val) {
> + if (TokenFactorIndex != -1)
> + return SDOperand();
Is it necessary to abort the optimization here? You are creating a new
TokenFactor node below, right? Why not just trim it? Perhaps
SelectionDAG::getNode should ensure TokenFactor nodes do have
duplicate operands?
Evan
>
> + TokenFactorIndex = i;
> + Ld = cast<LoadSDNode>(St->getValue());
> + } else
> + Ops.push_back(ChainVal->getOperand(i));
> + }
> + }
> + if (Ld) {
> + // If we are a 64-bit capable x86, lower to a single movq
> load/store pair.
> + if (Subtarget->is64Bit()) {
> + SDOperand NewLd = DAG.getLoad(MVT::i64, Ld->getChain(),
> + Ld->getBasePtr(), Ld-
> >getSrcValue(),
> + Ld->getSrcValueOffset(), Ld-
> >isVolatile(),
> + Ld->getAlignment());
> + SDOperand NewChain = NewLd.getValue(1);
> + if (TokenFactorIndex != -1) {
> + Ops.push_back(NewLd);
> + NewChain = DAG.getNode(ISD::TokenFactor, MVT::Other,
> &Ops[0],
> + Ops.size());
> + }
> + return DAG.getStore(NewChain, NewLd, St->getBasePtr(),
> + St->getSrcValue(), St-
> >getSrcValueOffset(),
> + St->isVolatile(), St->getAlignment());
> + }
> +
> + // Otherwise, lower to two 32-bit copies.
> + SDOperand LoAddr = Ld->getBasePtr();
> + SDOperand HiAddr = DAG.getNode(ISD::ADD, MVT::i32, LoAddr,
> + DAG.getConstant(MVT::i32, 4));
> +
> + SDOperand LoLd = DAG.getLoad(MVT::i32, Ld->getChain(), LoAddr,
> + Ld->getSrcValue(), Ld-
> >getSrcValueOffset(),
> + Ld->isVolatile(), Ld-
> >getAlignment());
> + SDOperand HiLd = DAG.getLoad(MVT::i32, Ld->getChain(), HiAddr,
> + Ld->getSrcValue(), Ld-
> >getSrcValueOffset()+4,
> + Ld->isVolatile(),
> + MinAlign(Ld->getAlignment(), 4));
> +
> + SDOperand NewChain = LoLd.getValue(1);
> + if (TokenFactorIndex != -1) {
> + Ops.push_back(LoLd);
> + Ops.push_back(HiLd);
> + NewChain = DAG.getNode(ISD::TokenFactor, MVT::Other, &Ops[0],
> + Ops.size());
> + }
> +
> + LoAddr = St->getBasePtr();
> + HiAddr = DAG.getNode(ISD::ADD, MVT::i32, LoAddr,
> + DAG.getConstant(MVT::i32, 4));
> +
> + SDOperand LoSt = DAG.getStore(NewChain, LoLd, LoAddr,
> St->getSrcValue(), St->getSrcValueOffset(),
> St->isVolatile(), St->getAlignment());
> + SDOperand HiSt = DAG.getStore(NewChain, HiLd, HiAddr,
> + St->getSrcValue(), St-
> >getSrcValueOffset()+4,
> + St->isVolatile(),
> + MinAlign(St->getAlignment(), 4));
> + return DAG.getNode(ISD::TokenFactor, MVT::Other, LoSt, HiSt);
> }
> -
> - // Otherwise, lower to two 32-bit copies.
> - SDOperand LoAddr = Ld->getBasePtr();
> - SDOperand HiAddr = DAG.getNode(ISD::ADD, MVT::i32, LoAddr,
> - DAG.getConstant(MVT::i32, 4));
> -
> - SDOperand LoLd = DAG.getLoad(MVT::i32, Ld->getChain(), LoAddr,
> - Ld->getSrcValue(), Ld-
> >getSrcValueOffset(),
> - Ld->isVolatile(), Ld-
> >getAlignment());
> - SDOperand HiLd = DAG.getLoad(MVT::i32, Ld->getChain(), HiAddr,
> - Ld->getSrcValue(), Ld-
> >getSrcValueOffset()+4,
> - Ld->isVolatile(),
> - MinAlign(Ld->getAlignment(), 4));
> -
> - LoAddr = St->getBasePtr();
> - HiAddr = DAG.getNode(ISD::ADD, MVT::i32, LoAddr,
> - DAG.getConstant(MVT::i32, 4));
> -
> - SDOperand LoSt = DAG.getStore(LoLd.getValue(1), LoLd, LoAddr,
> - St->getSrcValue(), St->getSrcValueOffset(),
> - St->isVolatile(), St->getAlignment());
> - SDOperand HiSt = DAG.getStore(HiLd.getValue(1), HiLd, HiAddr,
> - St->getSrcValue(), St-
> >getSrcValueOffset()+4,
> - St->isVolatile(),
> - MinAlign(St->getAlignment(), 4));
> - return DAG.getNode(ISD::TokenFactor, MVT::Other, LoSt, HiSt);
> }
> return SDOperand();
> }
>
>
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