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Diffstat (limited to 'lib/Target/AArch64/AArch64ISelLowering.cpp')
-rw-r--r--lib/Target/AArch64/AArch64ISelLowering.cpp182
1 files changed, 73 insertions, 109 deletions
diff --git a/lib/Target/AArch64/AArch64ISelLowering.cpp b/lib/Target/AArch64/AArch64ISelLowering.cpp
index 399b5eeaf5f5..6458d56c751f 100644
--- a/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -64,8 +64,16 @@ EnableAArch64ExtrGeneration("aarch64-extr-generation", cl::Hidden,
static cl::opt<bool>
EnableAArch64SlrGeneration("aarch64-shift-insert-generation", cl::Hidden,
- cl::desc("Allow AArch64 SLI/SRI formation"),
- cl::init(false));
+ cl::desc("Allow AArch64 SLI/SRI formation"),
+ cl::init(false));
+
+// FIXME: The necessary dtprel relocations don't seem to be supported
+// well in the GNU bfd and gold linkers at the moment. Therefore, by
+// default, for now, fall back to GeneralDynamic code generation.
+cl::opt<bool> EnableAArch64ELFLocalDynamicTLSGeneration(
+ "aarch64-elf-ldtls-generation", cl::Hidden,
+ cl::desc("Allow AArch64 Local Dynamic TLS code generation"),
+ cl::init(false));
AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM)
@@ -760,7 +768,7 @@ const char *AArch64TargetLowering::getTargetNodeName(unsigned Opcode) const {
case AArch64ISD::CSNEG: return "AArch64ISD::CSNEG";
case AArch64ISD::CSINC: return "AArch64ISD::CSINC";
case AArch64ISD::THREAD_POINTER: return "AArch64ISD::THREAD_POINTER";
- case AArch64ISD::TLSDESC_CALL: return "AArch64ISD::TLSDESC_CALL";
+ case AArch64ISD::TLSDESC_CALLSEQ: return "AArch64ISD::TLSDESC_CALLSEQ";
case AArch64ISD::ADC: return "AArch64ISD::ADC";
case AArch64ISD::SBC: return "AArch64ISD::SBC";
case AArch64ISD::ADDS: return "AArch64ISD::ADDS";
@@ -2023,18 +2031,19 @@ SDValue AArch64TargetLowering::LowerFormalArguments(
unsigned CurArgIdx = 0;
for (unsigned i = 0; i != NumArgs; ++i) {
MVT ValVT = Ins[i].VT;
- std::advance(CurOrigArg, Ins[i].OrigArgIndex - CurArgIdx);
- CurArgIdx = Ins[i].OrigArgIndex;
-
- // Get type of the original argument.
- EVT ActualVT = getValueType(CurOrigArg->getType(), /*AllowUnknown*/ true);
- MVT ActualMVT = ActualVT.isSimple() ? ActualVT.getSimpleVT() : MVT::Other;
- // If ActualMVT is i1/i8/i16, we should set LocVT to i8/i8/i16.
- if (ActualMVT == MVT::i1 || ActualMVT == MVT::i8)
- ValVT = MVT::i8;
- else if (ActualMVT == MVT::i16)
- ValVT = MVT::i16;
+ if (Ins[i].isOrigArg()) {
+ std::advance(CurOrigArg, Ins[i].getOrigArgIndex() - CurArgIdx);
+ CurArgIdx = Ins[i].getOrigArgIndex();
+ // Get type of the original argument.
+ EVT ActualVT = getValueType(CurOrigArg->getType(), /*AllowUnknown*/ true);
+ MVT ActualMVT = ActualVT.isSimple() ? ActualVT.getSimpleVT() : MVT::Other;
+ // If ActualMVT is i1/i8/i16, we should set LocVT to i8/i8/i16.
+ if (ActualMVT == MVT::i1 || ActualMVT == MVT::i8)
+ ValVT = MVT::i8;
+ else if (ActualMVT == MVT::i16)
+ ValVT = MVT::i16;
+ }
CCAssignFn *AssignFn = CCAssignFnForCall(CallConv, /*IsVarArg=*/false);
bool Res =
AssignFn(i, ValVT, ValVT, CCValAssign::Full, Ins[i].Flags, CCInfo);
@@ -3049,61 +3058,34 @@ AArch64TargetLowering::LowerDarwinGlobalTLSAddress(SDValue Op,
/// When accessing thread-local variables under either the general-dynamic or
/// local-dynamic system, we make a "TLS-descriptor" call. The variable will
/// have a descriptor, accessible via a PC-relative ADRP, and whose first entry
-/// is a function pointer to carry out the resolution. This function takes the
-/// address of the descriptor in X0 and returns the TPIDR_EL0 offset in X0. All
-/// other registers (except LR, NZCV) are preserved.
-///
-/// Thus, the ideal call sequence on AArch64 is:
-///
-/// adrp x0, :tlsdesc:thread_var
-/// ldr x8, [x0, :tlsdesc_lo12:thread_var]
-/// add x0, x0, :tlsdesc_lo12:thread_var
-/// .tlsdesccall thread_var
-/// blr x8
-/// (TPIDR_EL0 offset now in x0).
+/// is a function pointer to carry out the resolution.
///
-/// The ".tlsdesccall" directive instructs the assembler to insert a particular
-/// relocation to help the linker relax this sequence if it turns out to be too
-/// conservative.
+/// The sequence is:
+/// adrp x0, :tlsdesc:var
+/// ldr x1, [x0, #:tlsdesc_lo12:var]
+/// add x0, x0, #:tlsdesc_lo12:var
+/// .tlsdesccall var
+/// blr x1
+/// (TPIDR_EL0 offset now in x0)
///
-/// FIXME: we currently produce an extra, duplicated, ADRP instruction, but this
-/// is harmless.
-SDValue AArch64TargetLowering::LowerELFTLSDescCall(SDValue SymAddr,
- SDValue DescAddr, SDLoc DL,
- SelectionDAG &DAG) const {
+/// The above sequence must be produced unscheduled, to enable the linker to
+/// optimize/relax this sequence.
+/// Therefore, a pseudo-instruction (TLSDESC_CALLSEQ) is used to represent the
+/// above sequence, and expanded really late in the compilation flow, to ensure
+/// the sequence is produced as per above.
+SDValue AArch64TargetLowering::LowerELFTLSDescCallSeq(SDValue SymAddr, SDLoc DL,
+ SelectionDAG &DAG) const {
EVT PtrVT = getPointerTy();
- // The function we need to call is simply the first entry in the GOT for this
- // descriptor, load it in preparation.
- SDValue Func = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, SymAddr);
-
- // TLS calls preserve all registers except those that absolutely must be
- // trashed: X0 (it takes an argument), LR (it's a call) and NZCV (let's not be
- // silly).
- const TargetRegisterInfo *TRI =
- getTargetMachine().getSubtargetImpl()->getRegisterInfo();
- const AArch64RegisterInfo *ARI =
- static_cast<const AArch64RegisterInfo *>(TRI);
- const uint32_t *Mask = ARI->getTLSCallPreservedMask();
-
- // The function takes only one argument: the address of the descriptor itself
- // in X0.
- SDValue Glue, Chain;
- Chain = DAG.getCopyToReg(DAG.getEntryNode(), DL, AArch64::X0, DescAddr, Glue);
- Glue = Chain.getValue(1);
+ SDValue Chain = DAG.getEntryNode();
+ SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
- // We're now ready to populate the argument list, as with a normal call:
- SmallVector<SDValue, 6> Ops;
+ SmallVector<SDValue, 2> Ops;
Ops.push_back(Chain);
- Ops.push_back(Func);
Ops.push_back(SymAddr);
- Ops.push_back(DAG.getRegister(AArch64::X0, PtrVT));
- Ops.push_back(DAG.getRegisterMask(Mask));
- Ops.push_back(Glue);
- SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
- Chain = DAG.getNode(AArch64ISD::TLSDESC_CALL, DL, NodeTys, Ops);
- Glue = Chain.getValue(1);
+ Chain = DAG.getNode(AArch64ISD::TLSDESC_CALLSEQ, DL, NodeTys, Ops);
+ SDValue Glue = Chain.getValue(1);
return DAG.getCopyFromReg(Chain, DL, AArch64::X0, PtrVT, Glue);
}
@@ -3114,9 +3096,18 @@ AArch64TargetLowering::LowerELFGlobalTLSAddress(SDValue Op,
assert(Subtarget->isTargetELF() && "This function expects an ELF target");
assert(getTargetMachine().getCodeModel() == CodeModel::Small &&
"ELF TLS only supported in small memory model");
+ // Different choices can be made for the maximum size of the TLS area for a
+ // module. For the small address model, the default TLS size is 16MiB and the
+ // maximum TLS size is 4GiB.
+ // FIXME: add -mtls-size command line option and make it control the 16MiB
+ // vs. 4GiB code sequence generation.
const GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
TLSModel::Model Model = getTargetMachine().getTLSModel(GA->getGlobal());
+ if (!EnableAArch64ELFLocalDynamicTLSGeneration) {
+ if (Model == TLSModel::LocalDynamic)
+ Model = TLSModel::GeneralDynamic;
+ }
SDValue TPOff;
EVT PtrVT = getPointerTy();
@@ -3127,17 +3118,20 @@ AArch64TargetLowering::LowerELFGlobalTLSAddress(SDValue Op,
if (Model == TLSModel::LocalExec) {
SDValue HiVar = DAG.getTargetGlobalAddress(
- GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_G1);
+ GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_HI12);
SDValue LoVar = DAG.getTargetGlobalAddress(
GV, DL, PtrVT, 0,
- AArch64II::MO_TLS | AArch64II::MO_G0 | AArch64II::MO_NC);
+ AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
- TPOff = SDValue(DAG.getMachineNode(AArch64::MOVZXi, DL, PtrVT, HiVar,
- DAG.getTargetConstant(16, MVT::i32)),
- 0);
- TPOff = SDValue(DAG.getMachineNode(AArch64::MOVKXi, DL, PtrVT, TPOff, LoVar,
- DAG.getTargetConstant(0, MVT::i32)),
- 0);
+ SDValue TPWithOff_lo =
+ SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, ThreadBase,
+ HiVar, DAG.getTargetConstant(0, MVT::i32)),
+ 0);
+ SDValue TPWithOff =
+ SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, TPWithOff_lo,
+ LoVar, DAG.getTargetConstant(0, MVT::i32)),
+ 0);
+ return TPWithOff;
} else if (Model == TLSModel::InitialExec) {
TPOff = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
TPOff = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, TPOff);
@@ -3152,19 +3146,6 @@ AArch64TargetLowering::LowerELFGlobalTLSAddress(SDValue Op,
DAG.getMachineFunction().getInfo<AArch64FunctionInfo>();
MFI->incNumLocalDynamicTLSAccesses();
- // Accesses used in this sequence go via the TLS descriptor which lives in
- // the GOT. Prepare an address we can use to handle this.
- SDValue HiDesc = DAG.getTargetExternalSymbol(
- "_TLS_MODULE_BASE_", PtrVT, AArch64II::MO_TLS | AArch64II::MO_PAGE);
- SDValue LoDesc = DAG.getTargetExternalSymbol(
- "_TLS_MODULE_BASE_", PtrVT,
- AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
-
- // First argument to the descriptor call is the address of the descriptor
- // itself.
- SDValue DescAddr = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, HiDesc);
- DescAddr = DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, DescAddr, LoDesc);
-
// The call needs a relocation too for linker relaxation. It doesn't make
// sense to call it MO_PAGE or MO_PAGEOFF though so we need another copy of
// the address.
@@ -3173,40 +3154,23 @@ AArch64TargetLowering::LowerELFGlobalTLSAddress(SDValue Op,
// Now we can calculate the offset from TPIDR_EL0 to this module's
// thread-local area.
- TPOff = LowerELFTLSDescCall(SymAddr, DescAddr, DL, DAG);
+ TPOff = LowerELFTLSDescCallSeq(SymAddr, DL, DAG);
// Now use :dtprel_whatever: operations to calculate this variable's offset
// in its thread-storage area.
SDValue HiVar = DAG.getTargetGlobalAddress(
- GV, DL, MVT::i64, 0, AArch64II::MO_TLS | AArch64II::MO_G1);
+ GV, DL, MVT::i64, 0, AArch64II::MO_TLS | AArch64II::MO_HI12);
SDValue LoVar = DAG.getTargetGlobalAddress(
GV, DL, MVT::i64, 0,
- AArch64II::MO_TLS | AArch64II::MO_G0 | AArch64II::MO_NC);
-
- SDValue DTPOff =
- SDValue(DAG.getMachineNode(AArch64::MOVZXi, DL, PtrVT, HiVar,
- DAG.getTargetConstant(16, MVT::i32)),
- 0);
- DTPOff =
- SDValue(DAG.getMachineNode(AArch64::MOVKXi, DL, PtrVT, DTPOff, LoVar,
- DAG.getTargetConstant(0, MVT::i32)),
- 0);
-
- TPOff = DAG.getNode(ISD::ADD, DL, PtrVT, TPOff, DTPOff);
- } else if (Model == TLSModel::GeneralDynamic) {
- // Accesses used in this sequence go via the TLS descriptor which lives in
- // the GOT. Prepare an address we can use to handle this.
- SDValue HiDesc = DAG.getTargetGlobalAddress(
- GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_PAGE);
- SDValue LoDesc = DAG.getTargetGlobalAddress(
- GV, DL, PtrVT, 0,
AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
- // First argument to the descriptor call is the address of the descriptor
- // itself.
- SDValue DescAddr = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, HiDesc);
- DescAddr = DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, DescAddr, LoDesc);
-
+ TPOff = SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, TPOff, HiVar,
+ DAG.getTargetConstant(0, MVT::i32)),
+ 0);
+ TPOff = SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, TPOff, LoVar,
+ DAG.getTargetConstant(0, MVT::i32)),
+ 0);
+ } else if (Model == TLSModel::GeneralDynamic) {
// The call needs a relocation too for linker relaxation. It doesn't make
// sense to call it MO_PAGE or MO_PAGEOFF though so we need another copy of
// the address.
@@ -3214,7 +3178,7 @@ AArch64TargetLowering::LowerELFGlobalTLSAddress(SDValue Op,
DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
// Finally we can make a call to calculate the offset from tpidr_el0.
- TPOff = LowerELFTLSDescCall(SymAddr, DescAddr, DL, DAG);
+ TPOff = LowerELFTLSDescCallSeq(SymAddr, DL, DAG);
} else
llvm_unreachable("Unsupported ELF TLS access model");
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-04 20:08:32 +0000