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This patch that enables the Mips assembler to use symbols for offset for instructions

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This patch uses the generated instruction info tables to 
identify memory/load store instructions.
After successful matching and based on the operand type 
and size, it generates additional instructions to the output.

Contributor: Vladimir Medic



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177685 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jack Carter
2013-03-22 00:05:30 +00:00
parent 7697370adf
commit 25df6a93f3
3 changed files with 176 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

167
lib/Target/Mips/AsmParser/MipsAsmParser.cpp
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@@ -122,6 +122,9 @@ class MipsAsmParser : public MCTargetAsmParser {
SmallVectorImpl<MCInst> &Instructions);
void expandLoadAddressReg(MCInst &Inst, SMLoc IDLoc,
SmallVectorImpl<MCInst> &Instructions);
void expandMemInst(MCInst &Inst, SMLoc IDLoc,
SmallVectorImpl<MCInst> &Instructions,
bool isLoad,bool isImmOpnd);
bool reportParseError(StringRef ErrorMsg);
bool parseMemOffset(const MCExpr *&Res);
@@ -171,6 +174,9 @@ class MipsAsmParser : public MCTargetAsmParser {
unsigned getReg(int RC,int RegNo);
int getATReg();
bool processInstruction(MCInst &Inst, SMLoc IDLoc,
SmallVectorImpl<MCInst> &Instructions);
public:
MipsAsmParser(MCSubtargetInfo &sti, MCAsmParser &parser)
: MCTargetAsmParser(), STI(sti), Parser(parser) {
@@ -395,6 +401,56 @@ public:
};
}
namespace llvm {
extern const MCInstrDesc MipsInsts[];
}
static const MCInstrDesc &getInstDesc(unsigned Opcode) {
return MipsInsts[Opcode];
}
bool MipsAsmParser::processInstruction(MCInst &Inst, SMLoc IDLoc,
SmallVectorImpl<MCInst> &Instructions) {
const MCInstrDesc &MCID = getInstDesc(Inst.getOpcode());
Inst.setLoc(IDLoc);
if (MCID.mayLoad() || MCID.mayStore()) {
// Check the offset of memory operand, if it is a symbol
// reference or immediate we may have to expand instructions
for (unsigned i=0;i<MCID.getNumOperands();i++) {
const MCOperandInfo &OpInfo = MCID.OpInfo[i];
if ((OpInfo.OperandType == MCOI::OPERAND_MEMORY) ||
(OpInfo.OperandType == MCOI::OPERAND_UNKNOWN)) {
MCOperand &Op = Inst.getOperand(i);
if (Op.isImm()) {
int MemOffset = Op.getImm();
if (MemOffset < -32768 || MemOffset > 32767) {
// Offset can't exceed 16bit value
expandMemInst(Inst,IDLoc,Instructions,MCID.mayLoad(),true);
return false;
}
} else if (Op.isExpr()) {
const MCExpr *Expr = Op.getExpr();
if (Expr->getKind() == MCExpr::SymbolRef){
const MCSymbolRefExpr *SR =
static_cast<const MCSymbolRefExpr*>(Expr);
if (SR->getKind() == MCSymbolRefExpr::VK_None) {
// Expand symbol
expandMemInst(Inst,IDLoc,Instructions,MCID.mayLoad(),false);
return false;
}
}
}
}
}
}
if (needsExpansion(Inst))
expandInstruction(Inst, IDLoc, Instructions);
else
Instructions.push_back(Inst);
return false;
}
bool MipsAsmParser::needsExpansion(MCInst &Inst) {
switch(Inst.getOpcode()) {
@@ -541,28 +597,103 @@ void MipsAsmParser::expandLoadAddressImm(MCInst &Inst, SMLoc IDLoc,
}
}
void MipsAsmParser::expandMemInst(MCInst &Inst, SMLoc IDLoc,
SmallVectorImpl<MCInst> &Instructions,
bool isLoad,bool isImmOpnd) {
const MCSymbolRefExpr *SR;
MCInst TempInst;
unsigned ImmOffset,HiOffset,LoOffset;
const MCExpr *ExprOffset;
unsigned TmpRegNum;
unsigned AtRegNum = getReg((isMips64()) ? Mips::CPU64RegsRegClassID:
Mips::CPURegsRegClassID,
getATReg());
// 1st operand is either source or dst register
assert(Inst.getOperand(0).isReg() && "expected register operand kind");
unsigned RegOpNum = Inst.getOperand(0).getReg();
// 2nd operand is base register
assert(Inst.getOperand(1).isReg() && "expected register operand kind");
unsigned BaseRegNum = Inst.getOperand(1).getReg();
// 3rd operand is either immediate or expression
if (isImmOpnd) {
assert(Inst.getOperand(2).isImm() && "expected immediate operand kind");
ImmOffset = Inst.getOperand(2).getImm();
LoOffset = ImmOffset & 0x0000ffff;
HiOffset = (ImmOffset & 0xffff0000) >> 16;
// If msb of LoOffset is 1(negative number) we must increment HiOffset
if (LoOffset & 0x8000)
HiOffset++;
}
else
ExprOffset = Inst.getOperand(2).getExpr();
// All instructions will have the same location
TempInst.setLoc(IDLoc);
// 1st instruction in expansion is LUi. For load instruction we can use
// the dst register as a temporary if base and dst are different,
// but for stores we must use $at
TmpRegNum = (isLoad && (BaseRegNum != RegOpNum))?RegOpNum:AtRegNum;
TempInst.setOpcode(Mips::LUi);
TempInst.addOperand(MCOperand::CreateReg(TmpRegNum));
if (isImmOpnd)
TempInst.addOperand(MCOperand::CreateImm(HiOffset));
else {
if (ExprOffset->getKind() == MCExpr::SymbolRef) {
SR = static_cast<const MCSymbolRefExpr*>(ExprOffset);
const MCSymbolRefExpr *HiExpr = MCSymbolRefExpr::
Create(SR->getSymbol().getName(),
MCSymbolRefExpr::VK_Mips_ABS_HI,
getContext());
TempInst.addOperand(MCOperand::CreateExpr(HiExpr));
}
}
// Add the instruction to the list
Instructions.push_back(TempInst);
// and prepare TempInst for next instruction
TempInst.clear();
// which is add temp register to base
TempInst.setOpcode(Mips::ADDu);
TempInst.addOperand(MCOperand::CreateReg(TmpRegNum));
TempInst.addOperand(MCOperand::CreateReg(TmpRegNum));
TempInst.addOperand(MCOperand::CreateReg(BaseRegNum));
Instructions.push_back(TempInst);
TempInst.clear();
// and finaly, create original instruction with low part
// of offset and new base
TempInst.setOpcode(Inst.getOpcode());
TempInst.addOperand(MCOperand::CreateReg(RegOpNum));
TempInst.addOperand(MCOperand::CreateReg(TmpRegNum));
if (isImmOpnd)
TempInst.addOperand(MCOperand::CreateImm(LoOffset));
else {
if (ExprOffset->getKind() == MCExpr::SymbolRef) {
const MCSymbolRefExpr *LoExpr = MCSymbolRefExpr::
Create(SR->getSymbol().getName(),
MCSymbolRefExpr::VK_Mips_ABS_LO,
getContext());
TempInst.addOperand(MCOperand::CreateExpr(LoExpr));
}
}
Instructions.push_back(TempInst);
TempInst.clear();
}
bool MipsAsmParser::
MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
SmallVectorImpl<MCParsedAsmOperand*> &Operands,
MCStreamer &Out, unsigned &ErrorInfo,
bool MatchingInlineAsm) {
MCInst Inst;
SmallVector<MCInst, 8> Instructions;
unsigned MatchResult = MatchInstructionImpl(Operands, Inst, ErrorInfo,
MatchingInlineAsm);
switch (MatchResult) {
default: break;
case Match_Success: {
if (needsExpansion(Inst)) {
SmallVector<MCInst, 4> Instructions;
expandInstruction(Inst, IDLoc, Instructions);
for(unsigned i =0; i < Instructions.size(); i++){
Out.EmitInstruction(Instructions[i]);
}
} else {
Inst.setLoc(IDLoc);
Out.EmitInstruction(Inst);
}
if (processInstruction(Inst,IDLoc,Instructions))
return true;
for(unsigned i =0; i < Instructions.size(); i++)
Out.EmitInstruction(Instructions[i]);
return false;
}
case Match_MissingFeature:
@@ -898,24 +1029,25 @@ bool MipsAsmParser::parseRelocOperand(const MCExpr *&Res) {
// Check the type of the expression
if (const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(IdVal)) {
// it's a constant, evaluate lo or hi value
int Val = MCE->getValue();
// It's a constant, evaluate lo or hi value
if (Str == "lo") {
Val = Val & 0xffff;
short Val = MCE->getValue();
Res = MCConstantExpr::Create(Val, getContext());
} else if (Str == "hi") {
int Val = MCE->getValue();
int LoSign = Val & 0x8000;
Val = (Val & 0xffff0000) >> 16;
//lower part is treated as signed int, so if it is negative
//we must add 1 to hi part to compensate
// Lower part is treated as a signed int, so if it is negative
// we must add 1 to the hi part to compensate
if (LoSign)
Val++;
Res = MCConstantExpr::Create(Val, getContext());
}
Res = MCConstantExpr::Create(Val, getContext());
return false;
}
if (const MCSymbolRefExpr *MSRE = dyn_cast<MCSymbolRefExpr>(IdVal)) {
// it's a symbol, create symbolic expression from symbol
// It's a symbol, create symbolic expression from symbol
StringRef Symbol = MSRE->getSymbol().getName();
MCSymbolRefExpr::VariantKind VK = getVariantKind(Str);
Res = MCSymbolRefExpr::Create(Symbol,VK,getContext());
@@ -940,6 +1072,7 @@ bool MipsAsmParser::parseMemOffset(const MCExpr *&Res) {
switch(getLexer().getKind()) {
default:
return true;
case AsmToken::Identifier:
case AsmToken::Integer:
case AsmToken::Minus:
case AsmToken::Plus: