[PPC32] Support PLT calls for -msecure-plt -fpic
Summary:
In Secure PLT ABI, -fpic is similar to -fPIC. The differences are that:
* -fpic stores the address of _GLOBAL_OFFSET_TABLE_ in r30, while -fPIC stores .got2+0x8000.
* -fpic uses an addend of 0 for R_PPC_PLTREL24, while -fPIC uses 0x8000.
Reviewers: hfinkel, jhibbits, joerg, nemanjai, spetrovic
Reviewed By: jhibbits
Subscribers: adalava, kbarton, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63563
llvm-svn: 364324
diff --git a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
index 464e933..0d8c848 100644
--- a/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -461,6 +461,7 @@
StringRef Name = "__tls_get_addr";
MCSymbol *TlsGetAddr = OutContext.getOrCreateSymbol(Name);
MCSymbolRefExpr::VariantKind Kind = MCSymbolRefExpr::VK_None;
+ const Module *M = MF->getFunction().getParent();
assert(MI->getOperand(0).isReg() &&
((Subtarget->isPPC64() && MI->getOperand(0).getReg() == PPC::X3) ||
@@ -478,10 +479,10 @@
MCSymbolRefExpr::create(TlsGetAddr, Kind, OutContext);
// Add 32768 offset to the symbol so we follow up the latest GOT/PLT ABI.
- if (Kind == MCSymbolRefExpr::VK_PLT && Subtarget->isSecurePlt())
- TlsRef = MCBinaryExpr::createAdd(TlsRef,
- MCConstantExpr::create(32768, OutContext),
- OutContext);
+ if (Kind == MCSymbolRefExpr::VK_PLT && Subtarget->isSecurePlt() &&
+ M->getPICLevel() == PICLevel::BigPIC)
+ TlsRef = MCBinaryExpr::createAdd(
+ TlsRef, MCConstantExpr::create(32768, OutContext), OutContext);
const MachineOperand &MO = MI->getOperand(2);
const GlobalValue *GValue = MO.getGlobal();
MCSymbol *MOSymbol = getSymbol(GValue);
@@ -583,34 +584,30 @@
// Into: lwz %rt, .L0$poff - .L0$pb(%ri)
// add %rd, %rt, %ri
// or into (if secure plt mode is on):
- // addis r30, r30, .LTOC - .L0$pb@ha
- // addi r30, r30, .LTOC - .L0$pb@l
+ // addis r30, r30, {.LTOC,_GLOBAL_OFFSET_TABLE} - .L0$pb@ha
+ // addi r30, r30, {.LTOC,_GLOBAL_OFFSET_TABLE} - .L0$pb@l
// Get the offset from the GOT Base Register to the GOT
LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
if (Subtarget->isSecurePlt() && isPositionIndependent() ) {
unsigned PICR = TmpInst.getOperand(0).getReg();
- MCSymbol *LTOCSymbol = OutContext.getOrCreateSymbol(StringRef(".LTOC"));
+ MCSymbol *BaseSymbol = OutContext.getOrCreateSymbol(
+ M->getPICLevel() == PICLevel::SmallPIC ? "_GLOBAL_OFFSET_TABLE_"
+ : ".LTOC");
const MCExpr *PB =
- MCSymbolRefExpr::create(MF->getPICBaseSymbol(),
- OutContext);
+ MCSymbolRefExpr::create(MF->getPICBaseSymbol(), OutContext);
- const MCExpr *LTOCDeltaExpr =
- MCBinaryExpr::createSub(MCSymbolRefExpr::create(LTOCSymbol, OutContext),
- PB, OutContext);
+ const MCExpr *DeltaExpr = MCBinaryExpr::createSub(
+ MCSymbolRefExpr::create(BaseSymbol, OutContext), PB, OutContext);
- const MCExpr *LTOCDeltaHi =
- PPCMCExpr::createHa(LTOCDeltaExpr, false, OutContext);
- EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::ADDIS)
- .addReg(PICR)
- .addReg(PICR)
- .addExpr(LTOCDeltaHi));
+ const MCExpr *DeltaHi = PPCMCExpr::createHa(DeltaExpr, false, OutContext);
+ EmitToStreamer(
+ *OutStreamer,
+ MCInstBuilder(PPC::ADDIS).addReg(PICR).addReg(PICR).addExpr(DeltaHi));
- const MCExpr *LTOCDeltaLo =
- PPCMCExpr::createLo(LTOCDeltaExpr, false, OutContext);
- EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::ADDI)
- .addReg(PICR)
- .addReg(PICR)
- .addExpr(LTOCDeltaLo));
+ const MCExpr *DeltaLo = PPCMCExpr::createLo(DeltaExpr, false, OutContext);
+ EmitToStreamer(
+ *OutStreamer,
+ MCInstBuilder(PPC::ADDI).addReg(PICR).addReg(PICR).addExpr(DeltaLo));
return;
} else {
MCSymbol *PICOffset =
diff --git a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index 5a7dfed..543cac0 100644
--- a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -439,7 +439,8 @@
if (PPCLowering->getPointerTy(CurDAG->getDataLayout()) == MVT::i32) {
if (PPCSubTarget->isTargetELF()) {
GlobalBaseReg = PPC::R30;
- if (M->getPICLevel() == PICLevel::SmallPIC) {
+ if (!PPCSubTarget->isSecurePlt() &&
+ M->getPICLevel() == PICLevel::SmallPIC) {
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MoveGOTtoLR));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
MF->getInfo<PPCFunctionInfo>()->setUsesPICBase(true);
@@ -4395,11 +4396,9 @@
getGlobalBaseReg();
} break;
case PPCISD::CALL: {
- const Module *M = MF->getFunction().getParent();
-
if (PPCLowering->getPointerTy(CurDAG->getDataLayout()) != MVT::i32 ||
- (!TM.isPositionIndependent() || !PPCSubTarget->isSecurePlt()) ||
- !PPCSubTarget->isTargetELF() || M->getPICLevel() == PICLevel::SmallPIC)
+ !TM.isPositionIndependent() || !PPCSubTarget->isSecurePlt() ||
+ !PPCSubTarget->isTargetELF())
break;
SDValue Op = N->getOperand(1);
diff --git a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
index 858dc0b..027e6bd 100644
--- a/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
+++ b/llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
@@ -110,16 +110,16 @@
RefKind = MCSymbolRefExpr::VK_PLT;
const MachineFunction *MF = MO.getParent()->getParent()->getParent();
+ const Module *M = MF->getFunction().getParent();
const PPCSubtarget *Subtarget = &(MF->getSubtarget<PPCSubtarget>());
const TargetMachine &TM = Printer.TM;
const MCExpr *Expr = MCSymbolRefExpr::create(Symbol, RefKind, Ctx);
- // -msecure-plt option works only in PIC mode. If secure plt mode
- // is on add 32768 to symbol.
+ // If -msecure-plt -fPIC, add 32768 to symbol.
if (Subtarget->isSecurePlt() && TM.isPositionIndependent() &&
+ M->getPICLevel() == PICLevel::BigPIC &&
MO.getTargetFlags() == PPCII::MO_PLT)
- Expr = MCBinaryExpr::createAdd(Expr,
- MCConstantExpr::create(32768, Ctx),
- Ctx);
+ Expr =
+ MCBinaryExpr::createAdd(Expr, MCConstantExpr::create(32768, Ctx), Ctx);
if (!MO.isJTI() && MO.getOffset())
Expr = MCBinaryExpr::createAdd(Expr,