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-rw-r--r--llvm/lib/Target/X86/X86ISelPattern.cpp266
1 files changed, 141 insertions, 125 deletions
diff --git a/llvm/lib/Target/X86/X86ISelPattern.cpp b/llvm/lib/Target/X86/X86ISelPattern.cpp
index 0ec9f3c0204..3613b1fcb4d 100644
--- a/llvm/lib/Target/X86/X86ISelPattern.cpp
+++ b/llvm/lib/Target/X86/X86ISelPattern.cpp
@@ -345,7 +345,7 @@ namespace {
bool isFoldableLoad(SDOperand Op, SDOperand OtherOp);
void EmitFoldedLoad(SDOperand Op, X86AddressMode &AM);
-
+ bool TryToFoldLoadOpStore(SDNode *Node);
void EmitCMP(SDOperand LHS, SDOperand RHS, bool isOnlyUse);
bool EmitBranchCC(MachineBasicBlock *Dest, SDOperand Chain, SDOperand Cond);
@@ -2236,6 +2236,144 @@ unsigned ISel::SelectExpr(SDOperand N) {
return 0;
}
+/// TryToFoldLoadOpStore - Given a store node, try to fold together a
+/// load/op/store instruction. If successful return true.
+bool ISel::TryToFoldLoadOpStore(SDNode *Node) {
+ assert(Node->getOpcode() == ISD::STORE && "Can only do this for stores!");
+ SDOperand Chain = Node->getOperand(0);
+ SDOperand StVal = Node->getOperand(1);
+
+ // The chain has to be a load, the stored value must be an integer binary
+ // operation with one use.
+ if (Chain.getOpcode() != ISD::LOAD || !StVal.Val->hasOneUse() ||
+ StVal.Val->getNumOperands() != 2 ||
+ MVT::isFloatingPoint(StVal.getValueType()))
+ return false;
+
+ SDOperand TheLoad = Chain.getValue(0);
+
+ // Check to see if we are loading the same pointer that we're storing to.
+ if (TheLoad.getOperand(1) != Node->getOperand(2))
+ return false;
+
+ // Make sure that one of the operands of the binop is the load, and that the
+ // load folds into the binop.
+ if (((StVal.getOperand(0) != TheLoad ||
+ !isFoldableLoad(TheLoad, StVal.getOperand(1))) &&
+ (StVal.getOperand(1) != TheLoad ||
+ !isFoldableLoad(TheLoad, StVal.getOperand(0)))))
+ return false;
+
+ // Finally, check to see if this is one of the ops we can handle!
+ static const unsigned ADDTAB[] = {
+ X86::ADD8mi, X86::ADD16mi, X86::ADD32mi,
+ X86::ADD8mr, X86::ADD16mr, X86::ADD32mr,
+ };
+ static const unsigned SUBTAB[] = {
+ X86::SUB8mi, X86::SUB16mi, X86::SUB32mi,
+ X86::SUB8mr, X86::SUB16mr, X86::SUB32mr,
+ };
+ static const unsigned ANDTAB[] = {
+ X86::AND8mi, X86::AND16mi, X86::AND32mi,
+ X86::AND8mr, X86::AND16mr, X86::AND32mr,
+ };
+ static const unsigned ORTAB[] = {
+ X86::OR8mi, X86::OR16mi, X86::OR32mi,
+ X86::OR8mr, X86::OR16mr, X86::OR32mr,
+ };
+ static const unsigned XORTAB[] = {
+ X86::XOR8mi, X86::XOR16mi, X86::XOR32mi,
+ X86::XOR8mr, X86::XOR16mr, X86::XOR32mr,
+ };
+ static const unsigned SHLTAB[] = {
+ X86::SHL8mi, X86::SHL16mi, X86::SHL32mi,
+ /*Have to put the reg in CL*/0, 0, 0,
+ };
+ static const unsigned SARTAB[] = {
+ X86::SAR8mi, X86::SAR16mi, X86::SAR32mi,
+ /*Have to put the reg in CL*/0, 0, 0,
+ };
+ static const unsigned SHRTAB[] = {
+ X86::SHR8mi, X86::SHR16mi, X86::SHR32mi,
+ /*Have to put the reg in CL*/0, 0, 0,
+ };
+
+ const unsigned *TabPtr = 0;
+ switch (StVal.getOpcode()) {
+ default:
+ std::cerr << "CANNOT [mem] op= val: ";
+ StVal.Val->dump(); std::cerr << "\n";
+ case ISD::MUL:
+ case ISD::SDIV:
+ case ISD::UDIV:
+ case ISD::SREM:
+ case ISD::UREM: return false;
+
+ case ISD::ADD: TabPtr = ADDTAB; break;
+ case ISD::SUB: TabPtr = SUBTAB; break;
+ case ISD::AND: TabPtr = ANDTAB; break;
+ case ISD:: OR: TabPtr = ORTAB; break;
+ case ISD::XOR: TabPtr = XORTAB; break;
+ case ISD::SHL: TabPtr = SHLTAB; break;
+ case ISD::SRA: TabPtr = SARTAB; break;
+ case ISD::SRL: TabPtr = SHRTAB; break;
+ }
+
+ // Handle: [mem] op= CST
+ SDOperand Op0 = StVal.getOperand(0);
+ SDOperand Op1 = StVal.getOperand(1);
+ unsigned Opc;
+ if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Op1)) {
+ switch (Op0.getValueType()) { // Use Op0's type because of shifts.
+ default: break;
+ case MVT::i1:
+ case MVT::i8: Opc = TabPtr[0]; break;
+ case MVT::i16: Opc = TabPtr[1]; break;
+ case MVT::i32: Opc = TabPtr[2]; break;
+ }
+
+ if (Opc) {
+ X86AddressMode AM;
+ if (getRegPressure(TheLoad.getOperand(0)) >
+ getRegPressure(TheLoad.getOperand(1))) {
+ Select(TheLoad.getOperand(0));
+ SelectAddress(TheLoad.getOperand(1), AM);
+ } else {
+ SelectAddress(TheLoad.getOperand(1), AM);
+ Select(TheLoad.getOperand(0));
+ }
+
+ addFullAddress(BuildMI(BB, Opc, 4+1),AM).addImm(CN->getValue());
+ return true;
+ }
+ }
+
+ // If we have [mem] = V op [mem], try to turn it into:
+ // [mem] = [mem] op V.
+ if (Op1 == TheLoad && StVal.getOpcode() != ISD::SUB &&
+ StVal.getOpcode() != ISD::SHL && StVal.getOpcode() != ISD::SRA &&
+ StVal.getOpcode() != ISD::SRL)
+ std::swap(Op0, Op1);
+
+ if (Op0 != TheLoad) return false;
+
+ switch (Op0.getValueType()) {
+ default: return false;
+ case MVT::i1:
+ case MVT::i8: Opc = TabPtr[3]; break;
+ case MVT::i16: Opc = TabPtr[4]; break;
+ case MVT::i32: Opc = TabPtr[5]; break;
+ }
+
+ Select(TheLoad.getOperand(0));
+ X86AddressMode AM;
+ SelectAddress(TheLoad.getOperand(1), AM);
+ unsigned Reg = SelectExpr(Op1);
+ addFullAddress(BuildMI(BB, Opc, 4+1),AM).addReg(Reg);
+ return true;
+}
+
+
void ISel::Select(SDOperand N) {
unsigned Tmp1, Tmp2, Opc;
@@ -2488,130 +2626,8 @@ void ISel::Select(SDOperand N) {
}
// Check to see if this is a load/op/store combination.
- if (N.getOperand(1).Val->hasOneUse() &&
- N.getOperand(0).getOpcode() == ISD::LOAD &&
- N.getOperand(1).Val->getNumOperands() == 2 &&
- !MVT::isFloatingPoint(N.getOperand(0).getValue(0).getValueType())) {
- SDOperand TheLoad = N.getOperand(0).getValue(0);
-
- // See if the stored value is a simple binary operator that uses the load
- // as one of its operands.
- SDOperand Op = N.getOperand(1);
-
- // Check to see if we are loading the same pointer that we're storing to.
- if (TheLoad.getOperand(1) == N.getOperand(2) &&
- ((Op.getOperand(0) == TheLoad &&
- isFoldableLoad(TheLoad, Op.getOperand(1))) ||
- (Op.getOperand(1) == TheLoad &&
- isFoldableLoad(TheLoad, Op.getOperand(0))))) {
- // Finally, check to see if this is one of the ops we can handle!
- static const unsigned ADDTAB[] = {
- X86::ADD8mi, X86::ADD16mi, X86::ADD32mi,
- X86::ADD8mr, X86::ADD16mr, X86::ADD32mr,
- };
- static const unsigned SUBTAB[] = {
- X86::SUB8mi, X86::SUB16mi, X86::SUB32mi,
- X86::SUB8mr, X86::SUB16mr, X86::SUB32mr,
- };
- static const unsigned ANDTAB[] = {
- X86::AND8mi, X86::AND16mi, X86::AND32mi,
- X86::AND8mr, X86::AND16mr, X86::AND32mr,
- };
- static const unsigned ORTAB[] = {
- X86::OR8mi, X86::OR16mi, X86::OR32mi,
- X86::OR8mr, X86::OR16mr, X86::OR32mr,
- };
- static const unsigned XORTAB[] = {
- X86::XOR8mi, X86::XOR16mi, X86::XOR32mi,
- X86::XOR8mr, X86::XOR16mr, X86::XOR32mr,
- };
- static const unsigned SHLTAB[] = {
- X86::SHL8mi, X86::SHL16mi, X86::SHL32mi,
- /*Have to put the reg in CL*/0, 0, 0,
- };
- static const unsigned SARTAB[] = {
- X86::SAR8mi, X86::SAR16mi, X86::SAR32mi,
- /*Have to put the reg in CL*/0, 0, 0,
- };
- static const unsigned SHRTAB[] = {
- X86::SHR8mi, X86::SHR16mi, X86::SHR32mi,
- /*Have to put the reg in CL*/0, 0, 0,
- };
-
- const unsigned *TabPtr = 0;
- switch (Op.getOpcode()) {
- default: std::cerr << "CANNOT [mem] op= val: "; Op.Val->dump(); std::cerr << "\n"; break;
- case ISD::MUL:
- case ISD::SDIV:
- case ISD::UDIV:
- case ISD::SREM:
- case ISD::UREM: break;
-
- case ISD::ADD: TabPtr = ADDTAB; break;
- case ISD::SUB: TabPtr = SUBTAB; break;
- case ISD::AND: TabPtr = ANDTAB; break;
- case ISD:: OR: TabPtr = ORTAB; break;
- case ISD::XOR: TabPtr = XORTAB; break;
- case ISD::SHL: TabPtr = SHLTAB; break;
- case ISD::SRA: TabPtr = SARTAB; break;
- case ISD::SRL: TabPtr = SHRTAB; break;
- }
-
- if (TabPtr) {
- // Handle: [mem] op= CST
- SDOperand Op0 = Op.getOperand(0);
- SDOperand Op1 = Op.getOperand(1);
- if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(Op1)) {
- switch (Op0.getValueType()) { // Use Op0's type because of shifts.
- default: break;
- case MVT::i1:
- case MVT::i8: Opc = TabPtr[0]; break;
- case MVT::i16: Opc = TabPtr[1]; break;
- case MVT::i32: Opc = TabPtr[2]; break;
- }
-
- if (Opc) {
- if (getRegPressure(TheLoad.getOperand(0)) >
- getRegPressure(TheLoad.getOperand(1))) {
- Select(TheLoad.getOperand(0));
- SelectAddress(TheLoad.getOperand(1), AM);
- } else {
- SelectAddress(TheLoad.getOperand(1), AM);
- Select(TheLoad.getOperand(0));
- }
-
- addFullAddress(BuildMI(BB, Opc, 4+1),AM).addImm(CN->getValue());
- return;
- }
- }
-
- // If we have [mem] = V op [mem], try to turn it into:
- // [mem] = [mem] op V.
- if (Op1 == TheLoad && Op.getOpcode() != ISD::SUB &&
- Op.getOpcode() != ISD::SHL && Op.getOpcode() != ISD::SRA &&
- Op.getOpcode() != ISD::SRL)
- std::swap(Op0, Op1);
-
- if (Op0 == TheLoad) {
- switch (Op0.getValueType()) {
- default: break;
- case MVT::i1:
- case MVT::i8: Opc = TabPtr[3]; break;
- case MVT::i16: Opc = TabPtr[4]; break;
- case MVT::i32: Opc = TabPtr[5]; break;
- }
-
- if (Opc) {
- Select(TheLoad.getOperand(0));
- SelectAddress(TheLoad.getOperand(1), AM);
- unsigned Reg = SelectExpr(Op1);
- addFullAddress(BuildMI(BB, Opc, 4+1),AM).addReg(Reg);
- return;
- }
- }
- }
- }
- }
+ if (TryToFoldLoadOpStore(Node))
+ return;
switch (N.getOperand(1).getValueType()) {
default: assert(0 && "Cannot store this type!");
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