[mips] Expand JAL instructions when PIC is enabled.
Summary: This is the correct way to handle JAL instructions when PIC is enabled. Patch by Toma Tabacu Reviewers: seanbruno, tomatabacu Subscribers: brooks, seanbruno, emaste, llvm-commits Differential Revision: http://reviews.llvm.org/D6231 llvm-svn: 245305
This commit is contained in:
Daniel Sanders
parent
c5635a6af7
commit
63f4a5dcad
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@ -1318,6 +1318,44 @@ static bool hasShortDelaySlot(unsigned Opcode) {
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}
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}
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static const MCSymbol *getSingleMCSymbol(const MCExpr *Expr) {
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if (const MCSymbolRefExpr *SRExpr = dyn_cast<MCSymbolRefExpr>(Expr)) {
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return &SRExpr->getSymbol();
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}
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if (const MCBinaryExpr *BExpr = dyn_cast<MCBinaryExpr>(Expr)) {
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const MCSymbol *LHSSym = getSingleMCSymbol(BExpr->getLHS());
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const MCSymbol *RHSSym = getSingleMCSymbol(BExpr->getRHS());
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if (LHSSym)
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return LHSSym;
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if (RHSSym)
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return RHSSym;
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return nullptr;
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}
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if (const MCUnaryExpr *UExpr = dyn_cast<MCUnaryExpr>(Expr))
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return getSingleMCSymbol(UExpr->getSubExpr());
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return nullptr;
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}
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static unsigned countMCSymbolRefExpr(const MCExpr *Expr) {
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if (isa<MCSymbolRefExpr>(Expr))
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return 1;
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if (const MCBinaryExpr *BExpr = dyn_cast<MCBinaryExpr>(Expr))
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return countMCSymbolRefExpr(BExpr->getLHS()) +
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countMCSymbolRefExpr(BExpr->getRHS());
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if (const MCUnaryExpr *UExpr = dyn_cast<MCUnaryExpr>(Expr))
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return countMCSymbolRefExpr(UExpr->getSubExpr());
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return 0;
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}
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bool MipsAsmParser::processInstruction(MCInst &Inst, SMLoc IDLoc,
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SmallVectorImpl<MCInst> &Instructions) {
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const MCInstrDesc &MCID = getInstDesc(Inst.getOpcode());
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@ -1468,6 +1506,94 @@ bool MipsAsmParser::processInstruction(MCInst &Inst, SMLoc IDLoc,
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}
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}
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// This expansion is not in a function called by expandInstruction() because
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// the pseudo-instruction doesn't have a distinct opcode.
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if ((Inst.getOpcode() == Mips::JAL || Inst.getOpcode() == Mips::JAL_MM) &&
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inPicMode()) {
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warnIfNoMacro(IDLoc);
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const MCExpr *JalExpr = Inst.getOperand(0).getExpr();
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// We can do this expansion if there's only 1 symbol in the argument
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// expression.
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if (countMCSymbolRefExpr(JalExpr) > 1)
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return Error(IDLoc, "jal doesn't support multiple symbols in PIC mode");
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// FIXME: This is checking the expression can be handled by the later stages
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// of the assembler. We ought to leave it to those later stages but
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// we can't do that until we stop evaluateRelocExpr() rewriting the
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// expressions into non-equivalent forms.
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const MCSymbol *JalSym = getSingleMCSymbol(JalExpr);
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// FIXME: Add support for label+offset operands (currently causes an error).
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// FIXME: Add support for forward-declared local symbols.
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// FIXME: Add expansion for when the LargeGOT option is enabled.
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if (JalSym->isInSection() || JalSym->isTemporary()) {
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if (isABI_O32()) {
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// If it's a local symbol and the O32 ABI is being used, we expand to:
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// lw $25, 0($gp)
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// R_(MICRO)MIPS_GOT16 label
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// addiu $25, $25, 0
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// R_(MICRO)MIPS_LO16 label
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// jalr $25
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const MCExpr *Got16RelocExpr = evaluateRelocExpr(JalExpr, "got");
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const MCExpr *Lo16RelocExpr = evaluateRelocExpr(JalExpr, "lo");
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MCInst LwInst;
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LwInst.setOpcode(Mips::LW);
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LwInst.addOperand(MCOperand::createReg(Mips::T9));
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LwInst.addOperand(MCOperand::createReg(Mips::GP));
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LwInst.addOperand(MCOperand::createExpr(Got16RelocExpr));
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Instructions.push_back(LwInst);
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MCInst AddiuInst;
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AddiuInst.setOpcode(Mips::ADDiu);
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AddiuInst.addOperand(MCOperand::createReg(Mips::T9));
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AddiuInst.addOperand(MCOperand::createReg(Mips::T9));
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AddiuInst.addOperand(MCOperand::createExpr(Lo16RelocExpr));
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Instructions.push_back(AddiuInst);
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} else if (isABI_N32() || isABI_N64()) {
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// If it's a local symbol and the N32/N64 ABIs are being used,
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// we expand to:
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// lw/ld $25, 0($gp)
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// R_(MICRO)MIPS_GOT_DISP label
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// jalr $25
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const MCExpr *GotDispRelocExpr = evaluateRelocExpr(JalExpr, "got_disp");
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MCInst LoadInst;
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LoadInst.setOpcode(ABI.ArePtrs64bit() ? Mips::LD : Mips::LW);
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LoadInst.addOperand(MCOperand::createReg(Mips::T9));
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LoadInst.addOperand(MCOperand::createReg(Mips::GP));
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LoadInst.addOperand(MCOperand::createExpr(GotDispRelocExpr));
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Instructions.push_back(LoadInst);
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}
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} else {
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// If it's an external/weak symbol, we expand to:
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// lw/ld $25, 0($gp)
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// R_(MICRO)MIPS_CALL16 label
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// jalr $25
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const MCExpr *Call16RelocExpr = evaluateRelocExpr(JalExpr, "call16");
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MCInst LoadInst;
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LoadInst.setOpcode(ABI.ArePtrs64bit() ? Mips::LD : Mips::LW);
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LoadInst.addOperand(MCOperand::createReg(Mips::T9));
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LoadInst.addOperand(MCOperand::createReg(Mips::GP));
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LoadInst.addOperand(MCOperand::createExpr(Call16RelocExpr));
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Instructions.push_back(LoadInst);
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}
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MCInst JalrInst;
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JalrInst.setOpcode(inMicroMipsMode() ? Mips::JALR_MM : Mips::JALR);
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JalrInst.addOperand(MCOperand::createReg(Mips::RA));
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JalrInst.addOperand(MCOperand::createReg(Mips::T9));
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// FIXME: Add an R_(MICRO)MIPS_JALR relocation after the JALR.
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// This relocation is supposed to be an optimization hint for the linker
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// and is not necessary for correctness.
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Inst = JalrInst;
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}
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if (MCID.mayLoad() || MCID.mayStore()) {
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// Check the offset of memory operand, if it is a symbol
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// reference or immediate we may have to expand instructions.
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@ -41,7 +41,9 @@ bar:
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# Test R_MIPS_26 relocation.
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# rtdyld-check: decode_operand(insn1, 0)[25:0] = foo
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insn1:
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.option pic0
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jal foo
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.option pic2
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nop
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# Test R_MIPS_PC16 relocation.
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@ -0,0 +1,183 @@
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# RUN: llvm-mc %s -arch=mips -mcpu=mips32 -show-encoding |\
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# RUN: FileCheck %s -check-prefix=ALL -check-prefix=NORMAL -check-prefix=O32
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# RUN: llvm-mc %s -arch=mips -mcpu=mips64 -target-abi n32 -show-encoding |\
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# RUN: FileCheck %s -check-prefix=ALL -check-prefix=NORMAL -check-prefix=N32
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# RUN: llvm-mc %s -arch=mips64 -mcpu=mips64 -target-abi n64 -show-encoding |\
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# RUN: FileCheck %s -check-prefix=ALL -check-prefix=NORMAL -check-prefix=N64
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# RUN: llvm-mc %s -arch=mips -mcpu=mips32 -mattr=micromips -show-encoding |\
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# RUN: FileCheck %s -check-prefix=ALL -check-prefix=MICROMIPS -check-prefix=O32-MICROMIPS
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# RUN: llvm-mc %s -arch=mips -mcpu=mips64 -target-abi n32 -mattr=micromips -show-encoding |\
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# RUN: FileCheck %s -check-prefix=ALL -check-prefix=MICROMIPS -check-prefix=N32-MICROMIPS
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# RUN: llvm-mc %s -arch=mips64 -mcpu=mips64 -target-abi n64 -mattr=micromips -show-encoding |\
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# RUN: FileCheck %s -check-prefix=ALL -check-prefix=MICROMIPS -check-prefix=N64-MICROMIPS
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.weak weak_label
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.text
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.option pic2
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.ent local_label
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local_label:
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.frame $sp, 0, $ra
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.set noreorder
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jal local_label
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nop
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jal weak_label
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nop
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jal global_label
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nop
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jal .text
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nop
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# local labels ($tmp symbols)
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jal 1f
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nop
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.end local_label
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1:
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nop
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add $8, $8, $8
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nop
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# Expanding "jal local_label":
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# O32: lw $25, %got(local_label)($gp) # encoding: [0x8f,0x99,A,A]
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# O32: # fixup A - offset: 0, value: local_label@GOT, kind: fixup_Mips_GOT_Local
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# O32: addiu $25, $25, %lo(local_label) # encoding: [0x27,0x39,A,A]
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# O32: # fixup A - offset: 0, value: local_label@ABS_LO, kind: fixup_Mips_LO16
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# N32: lw $25, %got_disp(local_label)($gp) # encoding: [0x8f,0x99,A,A]
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# N32: # fixup A - offset: 0, value: local_label@GOT_DISP, kind: fixup_Mips_GOT_DISP
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# N64: ld $25, %got_disp(local_label)($gp) # encoding: [0xdf,0x99,A,A]
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# N64: # fixup A - offset: 0, value: local_label@GOT_DISP, kind: fixup_Mips_GOT_DISP
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# O32-MICROMIPS: lw $25, %got(local_label)($gp) # encoding: [0xff,0x3c,A,A]
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# O32-MICROMIPS: # fixup A - offset: 0, value: local_label@GOT, kind: fixup_MICROMIPS_GOT16
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# O32-MICROMIPS: addiu $25, $25, %lo(local_label) # encoding: [0x33,0x39,A,A]
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# O32-MICROMIPS: # fixup A - offset: 0, value: local_label@ABS_LO, kind: fixup_MICROMIPS_LO16
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# N32-MICROMIPS: lw $25, %got_disp(local_label)($gp) # encoding: [0xff,0x3c,A,A]
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# N32-MICROMIPS: # fixup A - offset: 0, value: local_label@GOT_DISP, kind: fixup_MICROMIPS_GOT_DISP
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# N64-MICROMIPS: ld $25, %got_disp(local_label)($gp) # encoding: [0xdf,0x99,A,A]
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# N64-MICROMIPS: # fixup A - offset: 0, value: local_label@GOT_DISP, kind: fixup_MICROMIPS_GOT_DISP
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# NORMAL: jalr $25 # encoding: [0x03,0x20,0xf8,0x09]
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# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
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# ALL: nop # encoding: [0x00,0x00,0x00,0x00]
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# Expanding "jal weak_label":
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# O32: lw $25, %call16(weak_label)($gp) # encoding: [0x8f,0x99,A,A]
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# O32: # fixup A - offset: 0, value: weak_label@GOT_CALL, kind: fixup_Mips_CALL16
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# N32: lw $25, %call16(weak_label)($gp) # encoding: [0x8f,0x99,A,A]
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# N32: # fixup A - offset: 0, value: weak_label@GOT_CALL, kind: fixup_Mips_CALL16
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# N64: ld $25, %call16(weak_label)($gp) # encoding: [0xdf,0x99,A,A]
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# N64: # fixup A - offset: 0, value: weak_label@GOT_CALL, kind: fixup_Mips_CALL16
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# O32-MICROMIPS: lw $25, %call16(weak_label)($gp) # encoding: [0xff,0x3c,A,A]
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# O32-MICROMIPS: # fixup A - offset: 0, value: weak_label@GOT_CALL, kind: fixup_MICROMIPS_CALL16
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# N32-MICROMIPS: lw $25, %call16(weak_label)($gp) # encoding: [0xff,0x3c,A,A]
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# N32-MICROMIPS: # fixup A - offset: 0, value: weak_label@GOT_CALL, kind: fixup_MICROMIPS_CALL16
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# N64-MICROMIPS: ld $25, %call16(weak_label)($gp) # encoding: [0xdf,0x99,A,A]
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# N64-MICROMIPS: # fixup A - offset: 0, value: weak_label@GOT_CALL, kind: fixup_MICROMIPS_CALL16
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# NORMAL: jalr $25 # encoding: [0x03,0x20,0xf8,0x09]
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# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
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# ALL: nop # encoding: [0x00,0x00,0x00,0x00]
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# Expanding "jal global_label":
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# O32: lw $25, %call16(global_label)($gp) # encoding: [0x8f,0x99,A,A]
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# O32: # fixup A - offset: 0, value: global_label@GOT_CALL, kind: fixup_Mips_CALL16
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# N32: lw $25, %call16(global_label)($gp) # encoding: [0x8f,0x99,A,A]
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# N32: # fixup A - offset: 0, value: global_label@GOT_CALL, kind: fixup_Mips_CALL16
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# N64: ld $25, %call16(global_label)($gp) # encoding: [0xdf,0x99,A,A]
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# N64: # fixup A - offset: 0, value: global_label@GOT_CALL, kind: fixup_Mips_CALL16
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# O32-MICROMIPS: lw $25, %call16(global_label)($gp) # encoding: [0xff,0x3c,A,A]
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# O32-MICROMIPS: # fixup A - offset: 0, value: global_label@GOT_CALL, kind: fixup_MICROMIPS_CALL16
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# N32-MICROMIPS: lw $25, %call16(global_label)($gp) # encoding: [0xff,0x3c,A,A]
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# N32-MICROMIPS: # fixup A - offset: 0, value: global_label@GOT_CALL, kind: fixup_MICROMIPS_CALL16
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# N64-MICROMIPS: ld $25, %call16(global_label)($gp) # encoding: [0xdf,0x99,A,A]
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# N64-MICROMIPS: # fixup A - offset: 0, value: global_label@GOT_CALL, kind: fixup_MICROMIPS_CALL16
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# NORMAL: jalr $25 # encoding: [0x03,0x20,0xf8,0x09]
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# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
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# ALL: nop # encoding: [0x00,0x00,0x00,0x00]
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# FIXME: The .text section MCSymbol isn't created when printing assembly. However,
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# it is created when generating an ELF object file.
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# Expanding "jal .text":
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# O32-FIXME: lw $25, %got(.text)($gp) # encoding: [0x8f,0x99,A,A]
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# O32-FIXME: # fixup A - offset: 0, value: .text@GOT, kind: fixup_Mips_GOT_Local
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# O32-FIXME: addiu $25, $25, %lo(.text) # encoding: [0x27,0x39,A,A]
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# O32-FIXME: # fixup A - offset: 0, value: .text@ABS_LO, kind: fixup_Mips_LO16
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# N32-FIXME: lw $25, %got_disp(.text)($gp) # encoding: [0x8f,0x99,A,A]
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# N32-FIXME: # fixup A - offset: 0, value: .text@GOT_DISP, kind: fixup_Mips_GOT_DISP
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# N64-FIXME: ld $25, %got_disp(.text)($gp) # encoding: [0xdf,0x99,A,A]
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# N64-FIXME: # fixup A - offset: 0, value: .text@GOT_DISP, kind: fixup_Mips_GOT_DISP
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# O32-MICROMIPS-FIXME: lw $25, %got(.text)($gp) # encoding: [0xff,0x3c,A,A]
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# O32-MICROMIPS-FIXME: # fixup A - offset: 0, value: .text@GOT, kind: fixup_MICROMIPS_GOT16
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# O32-MICROMIPS-FIXME: addiu $25, $25, %lo(.text) # encoding: [0x33,0x39,A,A]
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# O32-MICROMIPS-FIXME: # fixup A - offset: 0, value: .text@ABS_LO, kind: fixup_MICROMIPS_LO16
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# N32-MICROMIPS-FIXME: lw $25, %got_disp(.text)($gp) # encoding: [0xff,0x3c,A,A]
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# N32-MICROMIPS-FIXME: # fixup A - offset: 0, value: .text@GOT_DISP, kind: fixup_MICROMIPS_GOT_DISP
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# N64-MICROMIPS-FIXME: ld $25, %got_disp(.text)($gp) # encoding: [0xdf,0x99,A,A]
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# N64-MICROMIPS-FIXME: # fixup A - offset: 0, value: .text@GOT_DISP, kind: fixup_MICROMIPS_GOT_DISP
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# NORMAL: jalr $25 # encoding: [0x03,0x20,0xf8,0x09]
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# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
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# ALL: nop # encoding: [0x00,0x00,0x00,0x00]
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# Expanding "jal 1f":
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# O32: lw $25, %got($tmp0)($gp) # encoding: [0x8f,0x99,A,A]
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# O32: # fixup A - offset: 0, value: ($tmp0)@GOT, kind: fixup_Mips_GOT_Local
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# O32: addiu $25, $25, %lo($tmp0) # encoding: [0x27,0x39,A,A]
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# O32: # fixup A - offset: 0, value: ($tmp0)@ABS_LO, kind: fixup_Mips_LO16
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# N32: lw $25, %got_disp($tmp0)($gp) # encoding: [0x8f,0x99,A,A]
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# N32: # fixup A - offset: 0, value: ($tmp0)@GOT_DISP, kind: fixup_Mips_GOT_DISP
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# N64: ld $25, %got_disp($tmp0)($gp) # encoding: [0xdf,0x99,A,A]
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# N64: # fixup A - offset: 0, value: ($tmp0)@GOT_DISP, kind: fixup_Mips_GOT_DISP
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# O32-MICROMIPS: lw $25, %got($tmp0)($gp) # encoding: [0xff,0x3c,A,A]
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# O32-MICROMIPS: # fixup A - offset: 0, value: ($tmp0)@GOT, kind: fixup_MICROMIPS_GOT16
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# O32-MICROMIPS: addiu $25, $25, %lo($tmp0) # encoding: [0x33,0x39,A,A]
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# O32-MICROMIPS: # fixup A - offset: 0, value: ($tmp0)@ABS_LO, kind: fixup_MICROMIPS_LO16
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# N32-MICROMIPS: lw $25, %got_disp($tmp0)($gp) # encoding: [0xff,0x3c,A,A]
|
||||
# N32-MICROMIPS: # fixup A - offset: 0, value: ($tmp0)@GOT_DISP, kind: fixup_MICROMIPS_GOT_DISP
|
||||
|
||||
# N64-MICROMIPS: ld $25, %got_disp($tmp0)($gp) # encoding: [0xdf,0x99,A,A]
|
||||
# N64-MICROMIPS: # fixup A - offset: 0, value: ($tmp0)@GOT_DISP, kind: fixup_MICROMIPS_GOT_DISP
|
||||
|
||||
# NORMAL: jalr $25 # encoding: [0x03,0x20,0xf8,0x09]
|
||||
# MICROMIPS: jalr $ra, $25 # encoding: [0x03,0xf9,0x0f,0x3c]
|
||||
# ALL: nop # encoding: [0x00,0x00,0x00,0x00]
|
||||
|
|
@ -67,6 +67,11 @@
|
|||
ulw $8, 2($9)
|
||||
ulw $8, 0x8000($9)
|
||||
|
||||
jal foo
|
||||
.option pic2
|
||||
jal foo
|
||||
.option pic0
|
||||
|
||||
add $4, $5, $6
|
||||
|
||||
.set noreorder
|
||||
|
|
@ -187,5 +192,12 @@
|
|||
ulw $8, 0x8000($9)
|
||||
# CHECK: [[@LINE-1]]:3: warning: macro instruction expanded into multiple instructions
|
||||
|
||||
jal foo
|
||||
# CHECK-NOT: [[@LINE-1]]:3: warning: macro instruction expanded into multiple instructions
|
||||
.option pic2
|
||||
jal foo
|
||||
# CHECK: [[@LINE-1]]:3: warning: macro instruction expanded into multiple instructions
|
||||
.option pic0
|
||||
|
||||
add $4, $5, $6
|
||||
# CHECK-NOT: [[@LINE-1]]:3: warning: macro instruction expanded into multiple instructions
|
||||
|
|
|
|||
Loading…
Reference in New Issue