diff options
Diffstat (limited to 'llvm/lib/Target/ARM')
| -rw-r--r-- | llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp | 71 |
1 files changed, 66 insertions, 5 deletions
diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp index bb2628ef724..8b231d3f7d1 100644 --- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp +++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp @@ -257,9 +257,15 @@ class ARMAsmParser : public MCTargetAsmParser { bool hasThumb() const { return getSTI().getFeatureBits()[ARM::HasV4TOps]; } + bool hasThumb2() const { + return getSTI().getFeatureBits()[ARM::FeatureThumb2]; + } bool hasV6Ops() const { return getSTI().getFeatureBits()[ARM::HasV6Ops]; } + bool hasV6T2Ops() const { + return getSTI().getFeatureBits()[ARM::HasV6T2Ops]; + } bool hasV6MOps() const { return getSTI().getFeatureBits()[ARM::HasV6MOps]; } @@ -5247,7 +5253,6 @@ bool ARMAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic) { S = Parser.getTok().getLoc(); if (Mnemonic != "ldr") // only parse for ldr pseudo (e.g. ldr r0, =val) return Error(S, "unexpected token in operand"); - Parser.Lex(); // Eat '=' const MCExpr *SubExprVal; if (getParser().parseExpression(SubExprVal)) @@ -6870,10 +6875,10 @@ bool ARMAsmParser::processInstruction(MCInst &Inst, return true; case ARM::LDRConstPool: case ARM::tLDRConstPool: - case ARM::t2LDRConstPool: { - // Handle the pseudo instruction for ldr rn,= - // For now we always create the constant pool entry and load from it - // FIXME: Use a MOV or MVN when the immediate will fit + case ARM::t2LDRConstPool: { + // Pseudo instruction ldr rt, =immediate is converted to a + // MOV rt, immediate if immediate is known and representable + // otherwise we create a constant pool entry that we load from. MCInst TmpInst; if (Inst.getOpcode() == ARM::LDRConstPool) TmpInst.setOpcode(ARM::LDRi12); @@ -6884,6 +6889,62 @@ bool ARMAsmParser::processInstruction(MCInst &Inst, const ARMOperand &PoolOperand = static_cast<ARMOperand &>(*Operands[3]); const MCExpr *SubExprVal = PoolOperand.getConstantPoolImm(); + // If SubExprVal is a constant we may be able to use a MOV + if (isa<MCConstantExpr>(SubExprVal) && + Inst.getOperand(0).getReg() != ARM::PC && + Inst.getOperand(0).getReg() != ARM::SP) { + int64_t Value = + (int64_t) (cast<MCConstantExpr>(SubExprVal))->getValue(); + bool UseMov = true; + bool MovHasS = true; + if (Inst.getOpcode() == ARM::LDRConstPool) { + // ARM Constant + if (ARM_AM::getSOImmVal(Value) != -1) { + Value = ARM_AM::getSOImmVal(Value); + TmpInst.setOpcode(ARM::MOVi); + } + else if (ARM_AM::getSOImmVal(~Value) != -1) { + Value = ARM_AM::getSOImmVal(~Value); + TmpInst.setOpcode(ARM::MVNi); + } + else if (hasV6T2Ops() && + Value >=0 && Value < 65536) { + TmpInst.setOpcode(ARM::MOVi16); + MovHasS = false; + } + else + UseMov = false; + } + else { + // Thumb/Thumb2 Constant + if (hasThumb2() && + ARM_AM::getT2SOImmVal(Value) != -1) + TmpInst.setOpcode(ARM::t2MOVi); + else if (hasThumb2() && + ARM_AM::getT2SOImmVal(~Value) != -1) { + TmpInst.setOpcode(ARM::t2MVNi); + Value = ~Value; + } + else if (hasV8MBaseline() && + Value >=0 && Value < 65536) { + TmpInst.setOpcode(ARM::t2MOVi16); + MovHasS = false; + } + else + UseMov = false; + } + if (UseMov) { + TmpInst.addOperand(Inst.getOperand(0)); // Rt + TmpInst.addOperand(MCOperand::createImm(Value)); // Immediate + TmpInst.addOperand(Inst.getOperand(2)); // CondCode + TmpInst.addOperand(Inst.getOperand(3)); // CondCode + if (MovHasS) + TmpInst.addOperand(MCOperand::createReg(0)); // S + Inst = TmpInst; + return true; + } + } + // No opportunity to use MOV/MVN create constant pool const MCExpr *CPLoc = getTargetStreamer().addConstantPoolEntry(SubExprVal, PoolOperand.getStartLoc()); |
