[llvm-commits] [llvm] r55338 - in /llvm/trunk: lib/Target/X86/X86ISelDAGToDAG.cpp lib/Target/X86/X86ISelLowering.cpp test/CodeGen/X86/fold-call-2.ll
Evan Cheng
evan.cheng at apple.com
Mon Aug 25 14:27:19 PDT 2008
Author: evancheng
Date: Mon Aug 25 16:27:18 2008
New Revision: 55338
URL: http://llvm.org/viewvc/llvm-project?rev=55338&view=rev
Log:
Try approach to moving call address load inside of callseq_start. Now it's done during the preprocess of x86 isel. callseq_start's chain is changed to load's chain node; while load's chain is the last of callseq_start or the loads or copytoreg nodes inserted to move arguments to the right spot.
Modified:
llvm/trunk/lib/Target/X86/X86ISelDAGToDAG.cpp
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/test/CodeGen/X86/fold-call-2.ll
Modified: llvm/trunk/lib/Target/X86/X86ISelDAGToDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelDAGToDAG.cpp?rev=55338&r1=55337&r2=55338&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelDAGToDAG.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelDAGToDAG.cpp Mon Aug 25 16:27:18 2008
@@ -373,12 +373,12 @@
/// load's chain result.
static void MoveBelowTokenFactor(SelectionDAG *CurDAG, SDValue Load,
SDValue Store, SDValue TF) {
- std::vector<SDValue> Ops;
+ SmallVector<SDValue, 4> Ops;
for (unsigned i = 0, e = TF.Val->getNumOperands(); i != e; ++i)
- if (Load.Val == TF.Val->getOperand(i).Val)
- Ops.push_back(Load.Val->getOperand(0));
+ if (Load.Val == TF.getOperand(i).Val)
+ Ops.push_back(Load.getOperand(0));
else
- Ops.push_back(TF.Val->getOperand(i));
+ Ops.push_back(TF.getOperand(i));
CurDAG->UpdateNodeOperands(TF, &Ops[0], Ops.size());
CurDAG->UpdateNodeOperands(Load, TF, Load.getOperand(1), Load.getOperand(2));
CurDAG->UpdateNodeOperands(Store, Load.getValue(1), Store.getOperand(1),
@@ -411,6 +411,49 @@
return false;
}
+/// MoveBelowCallSeqStart - Replace CALLSEQ_START operand with load's chain
+/// operand and move load below the call's chain operand.
+static void MoveBelowCallSeqStart(SelectionDAG *CurDAG, SDValue Load,
+ SDValue Call, SDValue Chain) {
+ SmallVector<SDValue, 8> Ops;
+ for (unsigned i = 0, e = Chain.Val->getNumOperands(); i != e; ++i)
+ if (Load.Val == Chain.getOperand(i).Val)
+ Ops.push_back(Load.getOperand(0));
+ else
+ Ops.push_back(Chain.getOperand(i));
+ CurDAG->UpdateNodeOperands(Chain, &Ops[0], Ops.size());
+ CurDAG->UpdateNodeOperands(Load, Call.getOperand(0),
+ Load.getOperand(1), Load.getOperand(2));
+ Ops.clear();
+ Ops.push_back(SDValue(Load.Val, 1));
+ for (unsigned i = 1, e = Call.Val->getNumOperands(); i != e; ++i)
+ Ops.push_back(Call.getOperand(i));
+ CurDAG->UpdateNodeOperands(Call, &Ops[0], Ops.size());
+}
+
+/// isCalleeLoad - Return true if call address is a load and it can be
+/// moved below CALLSEQ_START and the chains leading up to the call.
+/// Return the CALLSEQ_START by reference as a second output.
+static bool isCalleeLoad(SDValue Callee, SDValue &Chain) {
+ if (Callee.Val == Chain.Val || !Callee.hasOneUse())
+ return false;
+ LoadSDNode *LD = dyn_cast<LoadSDNode>(Callee.Val);
+ if (!LD ||
+ LD->isVolatile() ||
+ LD->getAddressingMode() != ISD::UNINDEXED ||
+ LD->getExtensionType() != ISD::NON_EXTLOAD)
+ return false;
+
+ // Now let's find the callseq_start.
+ while (Chain.getOpcode() != ISD::CALLSEQ_START) {
+ if (!Chain.hasOneUse())
+ return false;
+ Chain = Chain.getOperand(0);
+ }
+ return Chain.getOperand(0).Val == Callee.Val;
+}
+
+
/// PreprocessForRMW - Preprocess the DAG to make instruction selection better.
/// This is only run if not in -fast mode (aka -O0).
/// This allows the instruction selector to pick more read-modify-write
@@ -454,9 +497,39 @@
void X86DAGToDAGISel::PreprocessForRMW() {
for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
E = CurDAG->allnodes_end(); I != E; ++I) {
+ if (I->getOpcode() == X86ISD::CALL) {
+ /// Also try moving call address load from outside callseq_start to just
+ /// before the call to allow it to be folded.
+ ///
+ /// [Load chain]
+ /// ^
+ /// |
+ /// [Load]
+ /// ^ ^
+ /// | |
+ /// / \--
+ /// / |
+ ///[CALLSEQ_START] |
+ /// ^ |
+ /// | |
+ /// [LOAD/C2Reg] |
+ /// | |
+ /// \ /
+ /// \ /
+ /// [CALL]
+ SDValue Chain = I->getOperand(0);
+ SDValue Load = I->getOperand(1);
+ if (!isCalleeLoad(Load, Chain))
+ continue;
+ MoveBelowCallSeqStart(CurDAG, Load, SDValue(I, 0), Chain);
+ ++NumLoadMoved;
+ continue;
+ }
+
if (!ISD::isNON_TRUNCStore(I))
continue;
SDValue Chain = I->getOperand(0);
+
if (Chain.Val->getOpcode() != ISD::TokenFactor)
continue;
@@ -471,35 +544,35 @@
SDValue Load;
unsigned Opcode = N1.Val->getOpcode();
switch (Opcode) {
- case ISD::ADD:
- case ISD::MUL:
- case ISD::AND:
- case ISD::OR:
- case ISD::XOR:
- case ISD::ADDC:
- case ISD::ADDE:
- case ISD::VECTOR_SHUFFLE: {
- SDValue N10 = N1.getOperand(0);
- SDValue N11 = N1.getOperand(1);
- RModW = isRMWLoad(N10, Chain, N2, Load);
- if (!RModW)
- RModW = isRMWLoad(N11, Chain, N2, Load);
- break;
- }
- case ISD::SUB:
- case ISD::SHL:
- case ISD::SRA:
- case ISD::SRL:
- case ISD::ROTL:
- case ISD::ROTR:
- case ISD::SUBC:
- case ISD::SUBE:
- case X86ISD::SHLD:
- case X86ISD::SHRD: {
- SDValue N10 = N1.getOperand(0);
- RModW = isRMWLoad(N10, Chain, N2, Load);
- break;
- }
+ case ISD::ADD:
+ case ISD::MUL:
+ case ISD::AND:
+ case ISD::OR:
+ case ISD::XOR:
+ case ISD::ADDC:
+ case ISD::ADDE:
+ case ISD::VECTOR_SHUFFLE: {
+ SDValue N10 = N1.getOperand(0);
+ SDValue N11 = N1.getOperand(1);
+ RModW = isRMWLoad(N10, Chain, N2, Load);
+ if (!RModW)
+ RModW = isRMWLoad(N11, Chain, N2, Load);
+ break;
+ }
+ case ISD::SUB:
+ case ISD::SHL:
+ case ISD::SRA:
+ case ISD::SRL:
+ case ISD::ROTL:
+ case ISD::ROTR:
+ case ISD::SUBC:
+ case ISD::SUBE:
+ case X86ISD::SHLD:
+ case X86ISD::SHRD: {
+ SDValue N10 = N1.getOperand(0);
+ RModW = isRMWLoad(N10, Chain, N2, Load);
+ break;
+ }
}
if (RModW) {
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=55338&r1=55337&r2=55338&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Aug 25 16:27:18 2008
@@ -1457,12 +1457,12 @@
SDValue X86TargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
MachineFunction &MF = DAG.getMachineFunction();
- SDValue Chain = Op.getOperand(0);
+ SDValue Chain = Op.getOperand(0);
unsigned CC = cast<ConstantSDNode>(Op.getOperand(1))->getValue();
bool isVarArg = cast<ConstantSDNode>(Op.getOperand(2))->getValue() != 0;
bool IsTailCall = cast<ConstantSDNode>(Op.getOperand(3))->getValue() != 0
&& CC == CallingConv::Fast && PerformTailCallOpt;
- SDValue Callee = Op.getOperand(4);
+ SDValue Callee = Op.getOperand(4);
bool Is64Bit = Subtarget->is64Bit();
bool IsStructRet = CallIsStructReturn(Op);
Modified: llvm/trunk/test/CodeGen/X86/fold-call-2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/fold-call-2.ll?rev=55338&r1=55337&r2=55338&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/fold-call-2.ll (original)
+++ llvm/trunk/test/CodeGen/X86/fold-call-2.ll Mon Aug 25 16:27:18 2008
@@ -1,5 +1,4 @@
; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin | grep mov | count 1
-; XFAIL: *
@f = external global void ()* ; <void ()**> [#uses=1]
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