Support jump tables when in PIC relocation model
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29318 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/AsmPrinter.h b/include/llvm/CodeGen/AsmPrinter.h
index c90a3ee..802fe6d 100644
--- a/include/llvm/CodeGen/AsmPrinter.h
+++ b/include/llvm/CodeGen/AsmPrinter.h
@@ -156,9 +156,15 @@
/// before emitting the constant pool for a function.
const char *ConstantPoolSection; // Defaults to "\t.section .rodata\n"
- /// JumpTableSection - This is the section that we SwitchToSection right
- /// before emitting the jump tables for a function.
- const char *JumpTableSection; // Defaults to "\t.section .rodata\n"
+ /// JumpTableDataSection - This is the section that we SwitchToSection right
+ /// before emitting the jump tables for a function when the relocation model
+ /// is not PIC.
+ const char *JumpTableDataSection; // Defaults to "\t.section .rodata\n"
+
+ /// JumpTableTextSection - This is the section that we SwitchToSection right
+ /// before emitting the jump tables for a function when the relocation model
+ /// is PIC.
+ const char *JumpTableTextSection; // Defaults to "\t.text\n"
/// StaticCtorsSection - This is the directive that is emitted to switch to
/// a section to emit the static constructor list.
diff --git a/lib/CodeGen/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter.cpp
index 6e5dab7..a0f377c 100644
--- a/lib/CodeGen/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter.cpp
@@ -52,7 +52,8 @@
DataSectionStartSuffix(""),
SectionEndDirectiveSuffix(0),
ConstantPoolSection("\t.section .rodata\n"),
- JumpTableSection("\t.section .rodata\n"),
+ JumpTableDataSection("\t.section .rodata\n"),
+ JumpTableTextSection("\t.text\n"),
StaticCtorsSection("\t.section .ctors,\"aw\",@progbits"),
StaticDtorsSection("\t.section .dtors,\"aw\",@progbits"),
FourByteConstantSection(0),
@@ -89,7 +90,7 @@
O << CurrentSection << TextSectionStartSuffix << '\n';
}
-/// SwitchToTextSection - Switch to the specified text section of the executable
+/// SwitchToDataSection - Switch to the specified data section of the executable
/// if we are not already in it!
///
void AsmPrinter::SwitchToDataSection(const char *NewSection,
@@ -209,29 +210,30 @@
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
if (JT.empty()) return;
const TargetData *TD = TM.getTargetData();
+ const char *PtrDataDirective = Data32bitsDirective;
- // FIXME: someday we need to handle PIC jump tables
- assert((TM.getRelocationModel() == Reloc::Static ||
- TM.getRelocationModel() == Reloc::DynamicNoPIC) &&
- "Unhandled relocation model emitting jump table information!");
-
- SwitchToDataSection(JumpTableSection, 0);
+ // Pick the directive to use to print the jump table entries, and switch to
+ // the appropriate section.
+ if (TM.getRelocationModel() == Reloc::PIC_) {
+ SwitchToTextSection(JumpTableTextSection, 0);
+ } else {
+ SwitchToDataSection(JumpTableDataSection, 0);
+ if (TD->getPointerSize() == 8)
+ PtrDataDirective = Data64bitsDirective;
+ }
EmitAlignment(Log2_32(TD->getPointerAlignment()));
- // Pick the directive to use based on the pointer size. FIXME: when we support
- // PIC jumptables, this should always use the 32-bit directive for label
- // differences.
- const char *PtrDataDirective = Data32bitsDirective;
- if (TD->getPointerSize() == 8)
- PtrDataDirective = Data64bitsDirective;
-
for (unsigned i = 0, e = JT.size(); i != e; ++i) {
O << PrivateGlobalPrefix << "JTI" << getFunctionNumber() << '_' << i
<< ":\n";
const std::vector<MachineBasicBlock*> &JTBBs = JT[i].MBBs;
for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
O << PtrDataDirective << ' ';
- printBasicBlockLabel(JTBBs[ii]);
+ printBasicBlockLabel(JTBBs[ii], false, false);
+ if (TM.getRelocationModel() == Reloc::PIC_) {
+ O << '-' << PrivateGlobalPrefix << "JTI" << getFunctionNumber()
+ << '_' << i;
+ }
O << '\n';
}
}
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index e8e7a47..76510f3 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -850,9 +850,15 @@
SDOperand Copy = DAG.getCopyFromReg(getRoot(), JT.Reg, PTy);
SDOperand IDX = DAG.getNode(ISD::MUL, PTy, Copy,
DAG.getConstant(PTyBytes, PTy));
- SDOperand ADD = DAG.getNode(ISD::ADD, PTy, IDX, DAG.getJumpTable(JT.JTI,PTy));
+ SDOperand TAB = DAG.getJumpTable(JT.JTI,PTy);
+ SDOperand ADD = DAG.getNode(ISD::ADD, PTy, IDX, TAB);
SDOperand LD = DAG.getLoad(PTy, Copy.getValue(1), ADD, DAG.getSrcValue(0));
- DAG.setRoot(DAG.getNode(ISD::BRIND, MVT::Other, LD.getValue(1), LD));
+ if (TLI.getTargetMachine().getRelocationModel() == Reloc::PIC_) {
+ ADD = DAG.getNode(ISD::ADD, PTy, LD.getValue(0), TAB);
+ DAG.setRoot(DAG.getNode(ISD::BRIND, MVT::Other, LD.getValue(1), ADD));
+ } else {
+ DAG.setRoot(DAG.getNode(ISD::BRIND, MVT::Other, LD.getValue(1), LD));
+ }
}
void SelectionDAGLowering::visitSwitch(SwitchInst &I) {
@@ -896,20 +902,20 @@
// to represent the switch.
MachineFunction *CurMF = CurMBB->getParent();
const BasicBlock *LLVMBB = CurMBB->getBasicBlock();
- Reloc::Model Relocs = TLI.getTargetMachine().getRelocationModel();
// If the switch has more than 5 blocks, and at least 31.25% dense, and the
// target supports indirect branches, then emit a jump table rather than
// lowering the switch to a binary tree of conditional branches.
// FIXME: Make this work with PIC code
if (TLI.isOperationLegal(ISD::BRIND, TLI.getPointerTy()) &&
- (Relocs == Reloc::Static || Relocs == Reloc::DynamicNoPIC) &&
Cases.size() > 5) {
uint64_t First = cast<ConstantIntegral>(Cases.front().first)->getRawValue();
uint64_t Last = cast<ConstantIntegral>(Cases.back().first)->getRawValue();
double Density = (double)Cases.size() / (double)((Last - First) + 1ULL);
if (Density >= 0.3125) {
+ Reloc::Model Relocs = TLI.getTargetMachine().getRelocationModel();
+
// Create a new basic block to hold the code for loading the address
// of the jump table, and jumping to it. Update successor information;
// we will either branch to the default case for the switch, or the jump
diff --git a/lib/Target/PowerPC/PPCAsmPrinter.cpp b/lib/Target/PowerPC/PPCAsmPrinter.cpp
index 6e75f3c..bf9c608 100644
--- a/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -282,8 +282,8 @@
Data64bitsDirective = 0; // we can't emit a 64-bit unit
AlignmentIsInBytes = false; // Alignment is by power of 2.
ConstantPoolSection = "\t.const\t";
- // FIXME: Conditionalize jump table section based on PIC
- JumpTableSection = ".const";
+ JumpTableDataSection = ".const";
+ JumpTableTextSection = "\t.text";
LCOMMDirective = "\t.lcomm\t";
StaticCtorsSection = ".mod_init_func";
StaticDtorsSection = ".mod_term_func";
diff --git a/lib/Target/X86/X86ATTAsmPrinter.cpp b/lib/Target/X86/X86ATTAsmPrinter.cpp
index 769aa73..712f34a 100755
--- a/lib/Target/X86/X86ATTAsmPrinter.cpp
+++ b/lib/Target/X86/X86ATTAsmPrinter.cpp
@@ -143,7 +143,9 @@
if (!isMemOp) O << '$';
O << PrivateGlobalPrefix << "JTI" << getFunctionNumber() << "_"
<< MO.getJumpTableIndex();
- // FIXME: PIC relocation model
+ if (Subtarget->TargetType == X86Subtarget::isDarwin &&
+ TM.getRelocationModel() == Reloc::PIC_)
+ O << "-\"L" << getFunctionNumber() << "$pb\"";
return;
}
case MachineOperand::MO_ConstantPoolIndex: {
diff --git a/lib/Target/X86/X86AsmPrinter.cpp b/lib/Target/X86/X86AsmPrinter.cpp
index 069b047..2c4b110 100644
--- a/lib/Target/X86/X86AsmPrinter.cpp
+++ b/lib/Target/X86/X86AsmPrinter.cpp
@@ -62,7 +62,7 @@
ZeroDirective = "\t.space\t"; // ".space N" emits N zeros.
PrivateGlobalPrefix = "L"; // Marker for constant pool idxs
ConstantPoolSection = "\t.const\n";
- JumpTableSection = "\t.const\n"; // FIXME: depends on PIC mode
+ JumpTableDataSection = "\t.const\n"; // FIXME: depends on PIC mode
FourByteConstantSection = "\t.literal4\n";
EightByteConstantSection = "\t.literal8\n";
LCOMMDirective = "\t.lcomm\t";