diff options
Diffstat (limited to 'llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp')
-rw-r--r-- | llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp index b39245b20b3..bd99fabb48c 100644 --- a/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp +++ b/llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp @@ -460,6 +460,14 @@ void SystemZAsmPrinter::EmitInstruction(const MachineInstr *MI) { } break; + case TargetOpcode::STACKMAP: + LowerSTACKMAP(*MI); + return; + + case TargetOpcode::PATCHPOINT: + LowerPATCHPOINT(*MI, Lower); + return; + default: Lower.lower(MI, LoweredMI); break; @@ -467,6 +475,123 @@ void SystemZAsmPrinter::EmitInstruction(const MachineInstr *MI) { EmitToStreamer(*OutStreamer, LoweredMI); } + +// Emit the largest nop instruction smaller than or equal to NumBytes +// bytes. Return the size of nop emitted. +static unsigned EmitNop(MCContext &OutContext, MCStreamer &OutStreamer, + unsigned NumBytes, const MCSubtargetInfo &STI) { + if (NumBytes < 2) { + llvm_unreachable("Zero nops?"); + return 0; + } + else if (NumBytes < 4) { + OutStreamer.EmitInstruction(MCInstBuilder(SystemZ::BCRAsm) + .addImm(0).addReg(SystemZ::R0D), STI); + return 2; + } + else if (NumBytes < 6) { + OutStreamer.EmitInstruction(MCInstBuilder(SystemZ::BCAsm) + .addImm(0).addReg(0).addImm(0).addReg(0), + STI); + return 4; + } + else { + MCSymbol *DotSym = OutContext.createTempSymbol(); + const MCSymbolRefExpr *Dot = MCSymbolRefExpr::create(DotSym, OutContext); + OutStreamer.EmitInstruction(MCInstBuilder(SystemZ::BRCLAsm) + .addImm(0).addExpr(Dot), STI); + OutStreamer.EmitLabel(DotSym); + return 6; + } +} + +void SystemZAsmPrinter::LowerSTACKMAP(const MachineInstr &MI) { + const SystemZInstrInfo *TII = + static_cast<const SystemZInstrInfo *>(MF->getSubtarget().getInstrInfo()); + + unsigned NumNOPBytes = MI.getOperand(1).getImm(); + + SM.recordStackMap(MI); + assert(NumNOPBytes % 2 == 0 && "Invalid number of NOP bytes requested!"); + + // Scan ahead to trim the shadow. + unsigned ShadowBytes = 0; + const MachineBasicBlock &MBB = *MI.getParent(); + MachineBasicBlock::const_iterator MII(MI); + ++MII; + while (ShadowBytes < NumNOPBytes) { + if (MII == MBB.end() || + MII->getOpcode() == TargetOpcode::PATCHPOINT || + MII->getOpcode() == TargetOpcode::STACKMAP) + break; + ShadowBytes += TII->getInstSizeInBytes(*MII); + if (MII->isCall()) + break; + ++MII; + } + + // Emit nops. + while (ShadowBytes < NumNOPBytes) + ShadowBytes += EmitNop(OutContext, *OutStreamer, NumNOPBytes - ShadowBytes, + getSubtargetInfo()); +} + +// Lower a patchpoint of the form: +// [<def>], <id>, <numBytes>, <target>, <numArgs> +void SystemZAsmPrinter::LowerPATCHPOINT(const MachineInstr &MI, + SystemZMCInstLower &Lower) { + SM.recordPatchPoint(MI); + PatchPointOpers Opers(&MI); + + unsigned EncodedBytes = 0; + const MachineOperand &CalleeMO = Opers.getCallTarget(); + + if (CalleeMO.isImm()) { + uint64_t CallTarget = CalleeMO.getImm(); + if (CallTarget) { + unsigned ScratchIdx = -1; + unsigned ScratchReg = 0; + do { + ScratchIdx = Opers.getNextScratchIdx(ScratchIdx + 1); + ScratchReg = MI.getOperand(ScratchIdx).getReg(); + } while (ScratchReg == SystemZ::R0D); + + // Materialize the call target address + EmitToStreamer(*OutStreamer, MCInstBuilder(SystemZ::LLILF) + .addReg(ScratchReg) + .addImm(CallTarget & 0xFFFFFFFF)); + EncodedBytes += 6; + if (CallTarget >> 32) { + EmitToStreamer(*OutStreamer, MCInstBuilder(SystemZ::IIHF) + .addReg(ScratchReg) + .addImm(CallTarget >> 32)); + EncodedBytes += 6; + } + + EmitToStreamer(*OutStreamer, MCInstBuilder(SystemZ::BASR) + .addReg(SystemZ::R14D) + .addReg(ScratchReg)); + EncodedBytes += 2; + } + } else if (CalleeMO.isGlobal()) { + const MCExpr *Expr = Lower.getExpr(CalleeMO, MCSymbolRefExpr::VK_PLT); + EmitToStreamer(*OutStreamer, MCInstBuilder(SystemZ::BRASL) + .addReg(SystemZ::R14D) + .addExpr(Expr)); + EncodedBytes += 6; + } + + // Emit padding. + unsigned NumBytes = Opers.getNumPatchBytes(); + assert(NumBytes >= EncodedBytes && + "Patchpoint can't request size less than the length of a call."); + assert((NumBytes - EncodedBytes) % 2 == 0 && + "Invalid number of NOP bytes requested!"); + while (EncodedBytes < NumBytes) + EncodedBytes += EmitNop(OutContext, *OutStreamer, NumBytes - EncodedBytes, + getSubtargetInfo()); +} + // Convert a SystemZ-specific constant pool modifier into the associated // MCSymbolRefExpr variant kind. static MCSymbolRefExpr::VariantKind @@ -521,6 +646,10 @@ bool SystemZAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, return false; } +void SystemZAsmPrinter::EmitEndOfAsmFile(Module &M) { + SM.serializeToStackMapSection(); +} + // Force static initialization. extern "C" void LLVMInitializeSystemZAsmPrinter() { RegisterAsmPrinter<SystemZAsmPrinter> X(getTheSystemZTarget()); |