* PIC codegen for X86/Linux has been implemented
* PIC-aware internal structures in X86 Codegen have been refactored
* Visibility (default/weak) has been added
* Docs fixes (external weak linkage, visibility, formatting)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33136 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ATTAsmPrinter.cpp b/lib/Target/X86/X86ATTAsmPrinter.cpp
index ccc2965..7edea6f 100755
--- a/lib/Target/X86/X86ATTAsmPrinter.cpp
+++ b/lib/Target/X86/X86ATTAsmPrinter.cpp
@@ -19,6 +19,7 @@
#include "X86MachineFunctionInfo.h"
#include "X86TargetMachine.h"
#include "X86TargetAsmInfo.h"
+#include "llvm/ADT/StringExtras.h"
#include "llvm/CallingConv.h"
#include "llvm/Module.h"
#include "llvm/Support/Mangler.h"
@@ -29,6 +30,21 @@
STATISTIC(EmittedInsts, "Number of machine instrs printed");
+static std::string computePICLabel(unsigned fnNumber,
+ const X86Subtarget* Subtarget)
+{
+ std::string label;
+
+ if (Subtarget->isTargetDarwin()) {
+ label = "\"L" + utostr_32(fnNumber) + "$pb\"";
+ } else if (Subtarget->isTargetELF()) {
+ label = ".Lllvm$" + utostr_32(fnNumber) + "$piclabel";
+ } else
+ assert(0 && "Don't know how to print PIC label!\n");
+
+ return label;
+}
+
/// getSectionForFunction - Return the section that we should emit the
/// specified function body into.
std::string X86ATTAsmPrinter::getSectionForFunction(const Function &F) const {
@@ -109,12 +125,15 @@
}
break;
}
+ if (F->hasHiddenVisibility())
+ O << "\t.hidden " << CurrentFnName << "\n";
+
O << CurrentFnName << ":\n";
// Add some workaround for linkonce linkage on Cygwin\MinGW
if (Subtarget->isTargetCygMing() &&
(F->getLinkage() == Function::LinkOnceLinkage ||
F->getLinkage() == Function::WeakLinkage))
- O << "_llvm$workaround$fake$stub_" << CurrentFnName << ":\n";
+ O << "Lllvm$workaround$fake$stub$" << CurrentFnName << ":\n";
if (Subtarget->isTargetDarwin() ||
Subtarget->isTargetELF() ||
@@ -193,9 +212,14 @@
if (!isMemOp) O << '$';
O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() << "_"
<< MO.getJumpTableIndex();
- if (X86PICStyle == PICStyle::Stub &&
- TM.getRelocationModel() == Reloc::PIC_)
- O << "-\"L" << getFunctionNumber() << "$pb\"";
+
+ if (TM.getRelocationModel() == Reloc::PIC_) {
+ if (Subtarget->isPICStyleStub())
+ O << "-\"L" << getFunctionNumber() << "$pb\"";
+ else if (Subtarget->isPICStyleGOT())
+ O << "@GOTOFF";
+ }
+
if (isMemOp && Subtarget->is64Bit() && !NotRIPRel)
O << "(%rip)";
return;
@@ -205,9 +229,14 @@
if (!isMemOp) O << '$';
O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
<< MO.getConstantPoolIndex();
- if (X86PICStyle == PICStyle::Stub &&
- TM.getRelocationModel() == Reloc::PIC_)
- O << "-\"L" << getFunctionNumber() << "$pb\"";
+
+ if (TM.getRelocationModel() == Reloc::PIC_) {
+ if (Subtarget->isPICStyleStub())
+ O << "-\"L" << getFunctionNumber() << "$pb\"";
+ if (Subtarget->isPICStyleGOT())
+ O << "@GOTOFF";
+ }
+
int Offset = MO.getOffset();
if (Offset > 0)
O << "+" << Offset;
@@ -228,11 +257,11 @@
bool isExt = (GV->isExternal() || GV->hasWeakLinkage() ||
GV->hasLinkOnceLinkage());
+ bool isHidden = GV->hasHiddenVisibility();
X86SharedAsmPrinter::decorateName(Name, GV);
- if (X86PICStyle == PICStyle::Stub &&
- TM.getRelocationModel() != Reloc::Static) {
+ if (Subtarget->isPICStyleStub()) {
// Link-once, External, or Weakly-linked global variables need
// non-lazily-resolved stubs
if (isExt) {
@@ -258,6 +287,12 @@
O << "__imp_";
}
O << Name;
+
+ if (Subtarget->isPICStyleGOT() && isCallOp && isa<Function>(GV)) {
+ // Assemble call via PLT for non-local symbols
+ if (!isHidden || isExt)
+ O << "@PLT";
+ }
}
if (GV->hasExternalWeakLinkage())
@@ -269,31 +304,55 @@
else if (Offset < 0)
O << Offset;
- if (isMemOp && Subtarget->is64Bit()) {
- if (isExt && TM.getRelocationModel() != Reloc::Static)
- O << "@GOTPCREL(%rip)";
- else if (!NotRIPRel)
- // Use rip when possible to reduce code size, except when index or
- // base register are also part of the address. e.g.
- // foo(%rip)(%rcx,%rax,4) is not legal
- O << "(%rip)";
+ if (isMemOp) {
+ if (isExt) {
+ if (Subtarget->isPICStyleGOT()) {
+ O << "@GOT";
+ } else if (Subtarget->isPICStyleRIPRel()) {
+ O << "@GOTPCREL(%rip)";
+ } if (Subtarget->is64Bit() && !NotRIPRel)
+ // Use rip when possible to reduce code size, except when
+ // index or base register are also part of the address. e.g.
+ // foo(%rip)(%rcx,%rax,4) is not legal
+ O << "(%rip)";
+ } else {
+ if (Subtarget->is64Bit() && !NotRIPRel)
+ O << "(%rip)";
+ else if (Subtarget->isPICStyleGOT())
+ O << "@GOTOFF";
+ }
}
return;
}
case MachineOperand::MO_ExternalSymbol: {
bool isCallOp = Modifier && !strcmp(Modifier, "call");
- if (isCallOp &&
- X86PICStyle == PICStyle::Stub &&
- TM.getRelocationModel() != Reloc::Static) {
- std::string Name(TAI->getGlobalPrefix());
- Name += MO.getSymbolName();
+ std::string Name(TAI->getGlobalPrefix());
+ Name += MO.getSymbolName();
+ if (isCallOp && Subtarget->isPICStyleStub()) {
FnStubs.insert(Name);
O << "L" << Name << "$stub";
return;
}
if (!isCallOp) O << '$';
- O << TAI->getGlobalPrefix() << MO.getSymbolName();
+ O << Name;
+
+ if (Subtarget->isPICStyleGOT()) {
+ std::string GOTName(TAI->getGlobalPrefix());
+ GOTName+="_GLOBAL_OFFSET_TABLE_";
+ if (Name == GOTName)
+ // Really hack! Emit extra offset to PC during printing GOT offset to
+ // compensate size of popl instruction. The resulting code should look
+ // like:
+ // call .piclabel
+ // piclabel:
+ // popl %some_register
+ // addl $_GLOBAL_ADDRESS_TABLE_ + [.-piclabel], %some_register
+ O << " + [.-" << computePICLabel(getFunctionNumber(), Subtarget) << "]";
+ }
+
+ if (isCallOp && Subtarget->isPICStyleGOT())
+ O << "@PLT";
if (!isCallOp && Subtarget->is64Bit())
O << "(%rip)";
@@ -366,8 +425,8 @@
}
void X86ATTAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
- O << "\"L" << getFunctionNumber() << "$pb\"\n";
- O << "\"L" << getFunctionNumber() << "$pb\":";
+ std::string label = computePICLabel(getFunctionNumber(), Subtarget);
+ O << label << "\n" << label << ":";
}