[PowerPC] 32-bit ELF PIC support
This adds initial support for PPC32 ELF PIC (Position Independent Code; the
-fPIC variety), thus rectifying a long-standing deficiency in the PowerPC
backend.
Patch by Justin Hibbits!
llvm-svn: 213427
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index bc057bf..e2826f7 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -1491,10 +1491,9 @@
HiOpFlags = PPCII::MO_HA;
LoOpFlags = PPCII::MO_LO;
- // Don't use the pic base if not in PIC relocation model. Or if we are on a
- // non-darwin platform. We don't support PIC on other platforms yet.
- bool isPIC = TM.getRelocationModel() == Reloc::PIC_ &&
- TM.getSubtarget<PPCSubtarget>().isDarwin();
+ // Don't use the pic base if not in PIC relocation model.
+ bool isPIC = TM.getRelocationModel() == Reloc::PIC_;
+
if (isPIC) {
HiOpFlags |= PPCII::MO_PIC_FLAG;
LoOpFlags |= PPCII::MO_PIC_FLAG;
@@ -1550,6 +1549,15 @@
unsigned MOHiFlag, MOLoFlag;
bool isPIC = GetLabelAccessInfo(DAG.getTarget(), MOHiFlag, MOLoFlag);
+
+ if (isPIC && Subtarget.isSVR4ABI()) {
+ SDValue GA = DAG.getTargetConstantPool(C, PtrVT, CP->getAlignment(),
+ PPCII::MO_PIC_FLAG);
+ SDLoc DL(CP);
+ return DAG.getNode(PPCISD::TOC_ENTRY, DL, MVT::i32, GA,
+ DAG.getNode(PPCISD::GlobalBaseReg, DL, PtrVT));
+ }
+
SDValue CPIHi =
DAG.getTargetConstantPool(C, PtrVT, CP->getAlignment(), 0, MOHiFlag);
SDValue CPILo =
@@ -1571,6 +1579,15 @@
unsigned MOHiFlag, MOLoFlag;
bool isPIC = GetLabelAccessInfo(DAG.getTarget(), MOHiFlag, MOLoFlag);
+
+ if (isPIC && Subtarget.isSVR4ABI()) {
+ SDValue GA = DAG.getTargetJumpTable(JT->getIndex(), PtrVT,
+ PPCII::MO_PIC_FLAG);
+ SDLoc DL(GA);
+ return DAG.getNode(PPCISD::TOC_ENTRY, SDLoc(JT), PtrVT, GA,
+ DAG.getNode(PPCISD::GlobalBaseReg, DL, PtrVT));
+ }
+
SDValue JTIHi = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, MOHiFlag);
SDValue JTILo = DAG.getTargetJumpTable(JT->getIndex(), PtrVT, MOLoFlag);
return LowerLabelRef(JTIHi, JTILo, isPIC, DAG);
@@ -1700,6 +1717,14 @@
unsigned MOHiFlag, MOLoFlag;
bool isPIC = GetLabelAccessInfo(DAG.getTarget(), MOHiFlag, MOLoFlag, GV);
+ if (isPIC && Subtarget.isSVR4ABI()) {
+ SDValue GA = DAG.getTargetGlobalAddress(GV, DL, PtrVT,
+ GSDN->getOffset(),
+ PPCII::MO_PIC_FLAG);
+ return DAG.getNode(PPCISD::TOC_ENTRY, DL, MVT::i32, GA,
+ DAG.getNode(PPCISD::GlobalBaseReg, DL, MVT::i32));
+ }
+
SDValue GAHi =
DAG.getTargetGlobalAddress(GV, DL, PtrVT, GSDN->getOffset(), MOHiFlag);
SDValue GALo =
@@ -3357,15 +3382,18 @@
// far-call stubs may be outside relocation limits for a BL instruction.
if (!DAG.getTarget().getSubtarget<PPCSubtarget>().isJITCodeModel()) {
unsigned OpFlags = 0;
- if (DAG.getTarget().getRelocationModel() != Reloc::Static &&
+ if ((DAG.getTarget().getRelocationModel() != Reloc::Static &&
(Subtarget.getTargetTriple().isMacOSX() &&
Subtarget.getTargetTriple().isMacOSXVersionLT(10, 5)) &&
(G->getGlobal()->isDeclaration() ||
- G->getGlobal()->isWeakForLinker())) {
+ G->getGlobal()->isWeakForLinker())) ||
+ (Subtarget.isTargetELF() && !isPPC64 &&
+ !G->getGlobal()->hasLocalLinkage() &&
+ DAG.getTarget().getRelocationModel() == Reloc::PIC_)) {
// PC-relative references to external symbols should go through $stub,
// unless we're building with the leopard linker or later, which
// automatically synthesizes these stubs.
- OpFlags = PPCII::MO_DARWIN_STUB;
+ OpFlags = PPCII::MO_PLT_OR_STUB;
}
// If the callee is a GlobalAddress/ExternalSymbol node (quite common,
@@ -3381,13 +3409,15 @@
if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
unsigned char OpFlags = 0;
- if (DAG.getTarget().getRelocationModel() != Reloc::Static &&
- (Subtarget.getTargetTriple().isMacOSX() &&
- Subtarget.getTargetTriple().isMacOSXVersionLT(10, 5))) {
+ if ((DAG.getTarget().getRelocationModel() != Reloc::Static &&
+ (Subtarget.getTargetTriple().isMacOSX() &&
+ Subtarget.getTargetTriple().isMacOSXVersionLT(10, 5))) ||
+ (Subtarget.isTargetELF() && !isPPC64 &&
+ DAG.getTarget().getRelocationModel() == Reloc::PIC_) ) {
// PC-relative references to external symbols should go through $stub,
// unless we're building with the leopard linker or later, which
// automatically synthesizes these stubs.
- OpFlags = PPCII::MO_DARWIN_STUB;
+ OpFlags = PPCII::MO_PLT_OR_STUB;
}
Callee = DAG.getTargetExternalSymbol(S->getSymbol(), Callee.getValueType(),
@@ -6613,7 +6643,10 @@
// Since FP is only updated here but NOT referenced, it's treated as GPR.
unsigned FP = (PVT == MVT::i64) ? PPC::X31 : PPC::R31;
unsigned SP = (PVT == MVT::i64) ? PPC::X1 : PPC::R1;
- unsigned BP = (PVT == MVT::i64) ? PPC::X30 : PPC::R30;
+ unsigned BP = (PVT == MVT::i64) ? PPC::X30 :
+ (Subtarget.isSVR4ABI() &&
+ MF->getTarget().getRelocationModel() == Reloc::PIC_ ?
+ PPC::R29 : PPC::R30);
MachineInstrBuilder MIB;