//===- AsmWriterEmitter.cpp - Generate an assembly writer -----------------===//
-//
+//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+//
//===----------------------------------------------------------------------===//
//
// This tablegen backend is emits an assembly printer for the current target.
#include "AsmWriterEmitter.h"
#include "CodeGenTarget.h"
#include "Record.h"
+#include <algorithm>
#include <ostream>
using namespace llvm;
MVT::ValueType VT) : OperandType(isMachineInstrOperand),
Str(Printer), MIOpNo(OpNo), OpVT(VT){}
+ bool operator!=(const AsmWriterOperand &Other) const {
+ if (OperandType != Other.OperandType || Str != Other.Str) return true;
+ if (OperandType == isMachineInstrOperand)
+ return MIOpNo != Other.MIOpNo || OpVT != Other.OpVT;
+ return false;
+ }
+ bool operator==(const AsmWriterOperand &Other) const {
+ return !operator!=(Other);
+ }
void EmitCode(std::ostream &OS) const;
};
struct AsmWriterInst {
std::vector<AsmWriterOperand> Operands;
const CodeGenInstruction *CGI;
-
+
AsmWriterInst(const CodeGenInstruction &CGI, unsigned Variant);
- void EmitCode(std::ostream &OS) const {
- for (unsigned i = 0, e = Operands.size(); i != e; ++i)
- Operands[i].EmitCode(OS);
- }
+
+ /// MatchesAllButOneOp - If this instruction is exactly identical to the
+ /// specified instruction except for one differing operand, return the
+ /// differing operand number. Otherwise return ~0.
+ unsigned MatchesAllButOneOp(const AsmWriterInst &Other) const;
+
private:
void AddLiteralString(const std::string &Str) {
// If the last operand was already a literal text string, append this to
if (OperandType == isLiteralTextOperand)
OS << "O << \"" << Str << "\"; ";
else
- OS << Str << "(MI, " << MIOpNo << ", MVT::" << getName(OpVT) << "); ";
+ OS << Str << "(MI, " << MIOpNo << ", MVT::" << getEnumName(OpVT) << "); ";
}
LastEmitted = DollarPos;
} else if (AsmString[DollarPos] == '{') {
if (inVariant)
- throw "Nested variants found for instruction '" + CGI.Name + "'!";
+ throw "Nested variants found for instruction '" +
+ CGI.TheDef->getName() + "'!";
LastEmitted = DollarPos+1;
inVariant = true; // We are now inside of the variant!
for (unsigned i = 0; i != Variant; ++i) {
std::string::size_type NP =
AsmString.find_first_of("|}", LastEmitted);
if (NP == std::string::npos)
- throw "Incomplete variant for instruction '" + CGI.Name + "'!";
+ throw "Incomplete variant for instruction '" +
+ CGI.TheDef->getName() + "'!";
LastEmitted = NP+1;
if (AsmString[NP] == '}') {
inVariant = false; // No text for this variant.
} else if (AsmString[DollarPos] == '|') {
if (!inVariant)
throw "'|' character found outside of a variant in instruction '"
- + CGI.Name + "'!";
+ + CGI.TheDef->getName() + "'!";
// Move to the end of variant list.
std::string::size_type NP = AsmString.find('}', LastEmitted);
if (NP == std::string::npos)
- throw "Incomplete variant for instruction '" + CGI.Name + "'!";
+ throw "Incomplete variant for instruction '" +
+ CGI.TheDef->getName() + "'!";
LastEmitted = NP+1;
inVariant = false;
} else if (AsmString[DollarPos] == '}') {
if (!inVariant)
throw "'}' character found outside of a variant in instruction '"
- + CGI.Name + "'!";
+ + CGI.TheDef->getName() + "'!";
LastEmitted = DollarPos+1;
inVariant = false;
} else if (DollarPos+1 != AsmString.size() &&
LastEmitted = DollarPos+2;
} else {
// Get the name of the variable.
- // TODO: should eventually handle ${foo}bar as $foo
std::string::size_type VarEnd = DollarPos+1;
+
+ // handle ${foo}bar as $foo by detecting whether the character following
+ // the dollar sign is a curly brace. If so, advance VarEnd and DollarPos
+ // so the variable name does not contain the leading curly brace.
+ bool hasCurlyBraces = false;
+ if (VarEnd < AsmString.size() && '{' == AsmString[VarEnd]) {
+ hasCurlyBraces = true;
+ ++DollarPos;
+ ++VarEnd;
+ }
+
while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd]))
++VarEnd;
std::string VarName(AsmString.begin()+DollarPos+1,
AsmString.begin()+VarEnd);
+
+ // In order to avoid starting the next string at the terminating curly
+ // brace, advance the end position past it if we found an opening curly
+ // brace.
+ if (hasCurlyBraces) {
+ if (VarEnd >= AsmString.size())
+ throw "Reached end of string before terminating curly brace in '"
+ + CGI.TheDef->getName() + "'";
+ if (AsmString[VarEnd] != '}')
+ throw "Variant name beginning with '{' did not end with '}' in '"
+ + CGI.TheDef->getName() + "'";
+ ++VarEnd;
+ }
if (VarName.empty())
- throw "Stray '$' in '" + CGI.Name + "' asm string, maybe you want $$?";
+ throw "Stray '$' in '" + CGI.TheDef->getName() +
+ "' asm string, maybe you want $$?";
unsigned OpNo = CGI.getOperandNamed(VarName);
CodeGenInstruction::OperandInfo OpInfo = CGI.OperandList[OpNo];
if (CGI.isTwoAddress && MIOp != 0) {
if (MIOp == 1)
throw "Should refer to operand #0 instead of #1 for two-address"
- " instruction '" + CGI.Name + "'!";
+ " instruction '" + CGI.TheDef->getName() + "'!";
--MIOp;
}
AddLiteralString("\\n");
}
+/// MatchesAllButOneOp - If this instruction is exactly identical to the
+/// specified instruction except for one differing operand, return the differing
+/// operand number. If more than one operand mismatches, return ~1, otherwise
+/// if the instructions are identical return ~0.
+unsigned AsmWriterInst::MatchesAllButOneOp(const AsmWriterInst &Other)const{
+ if (Operands.size() != Other.Operands.size()) return ~1;
+
+ unsigned MismatchOperand = ~0U;
+ for (unsigned i = 0, e = Operands.size(); i != e; ++i) {
+ if (Operands[i] != Other.Operands[i])
+ if (MismatchOperand != ~0U) // Already have one mismatch?
+ return ~1U;
+ else
+ MismatchOperand = i;
+ }
+ return MismatchOperand;
+}
+
+static void PrintCases(std::vector<std::pair<std::string,
+ AsmWriterOperand> > &OpsToPrint, std::ostream &O) {
+ O << " case " << OpsToPrint.back().first << ": ";
+ AsmWriterOperand TheOp = OpsToPrint.back().second;
+ OpsToPrint.pop_back();
+
+ // Check to see if any other operands are identical in this list, and if so,
+ // emit a case label for them.
+ for (unsigned i = OpsToPrint.size(); i != 0; --i)
+ if (OpsToPrint[i-1].second == TheOp) {
+ O << "\n case " << OpsToPrint[i-1].first << ": ";
+ OpsToPrint.erase(OpsToPrint.begin()+i-1);
+ }
+
+ // Finally, emit the code.
+ TheOp.EmitCode(O);
+ O << "break;\n";
+}
+
+
+/// EmitInstructions - Emit the last instruction in the vector and any other
+/// instructions that are suitably similar to it.
+static void EmitInstructions(std::vector<AsmWriterInst> &Insts,
+ std::ostream &O) {
+ AsmWriterInst FirstInst = Insts.back();
+ Insts.pop_back();
+
+ std::vector<AsmWriterInst> SimilarInsts;
+ unsigned DifferingOperand = ~0;
+ for (unsigned i = Insts.size(); i != 0; --i) {
+ unsigned DiffOp = Insts[i-1].MatchesAllButOneOp(FirstInst);
+ if (DiffOp != ~1U) {
+ if (DifferingOperand == ~0U) // First match!
+ DifferingOperand = DiffOp;
+
+ // If this differs in the same operand as the rest of the instructions in
+ // this class, move it to the SimilarInsts list.
+ if (DifferingOperand == DiffOp || DiffOp == ~0U) {
+ SimilarInsts.push_back(Insts[i-1]);
+ Insts.erase(Insts.begin()+i-1);
+ }
+ }
+ }
+
+ std::string Namespace = FirstInst.CGI->Namespace;
+
+ O << " case " << Namespace << "::"
+ << FirstInst.CGI->TheDef->getName() << ":\n";
+ for (unsigned i = 0, e = SimilarInsts.size(); i != e; ++i)
+ O << " case " << Namespace << "::"
+ << SimilarInsts[i].CGI->TheDef->getName() << ":\n";
+ for (unsigned i = 0, e = FirstInst.Operands.size(); i != e; ++i) {
+ if (i != DifferingOperand) {
+ // If the operand is the same for all instructions, just print it.
+ O << " ";
+ FirstInst.Operands[i].EmitCode(O);
+ } else {
+ // If this is the operand that varies between all of the instructions,
+ // emit a switch for just this operand now.
+ O << " switch (MI->getOpcode()) {\n";
+ std::vector<std::pair<std::string, AsmWriterOperand> > OpsToPrint;
+ OpsToPrint.push_back(std::make_pair(Namespace+"::"+
+ FirstInst.CGI->TheDef->getName(),
+ FirstInst.Operands[i]));
+
+ for (unsigned si = 0, e = SimilarInsts.size(); si != e; ++si) {
+ AsmWriterInst &AWI = SimilarInsts[si];
+ OpsToPrint.push_back(std::make_pair(Namespace+"::"+
+ AWI.CGI->TheDef->getName(),
+ AWI.Operands[i]));
+ }
+ std::reverse(OpsToPrint.begin(), OpsToPrint.end());
+ while (!OpsToPrint.empty())
+ PrintCases(OpsToPrint, O);
+ O << " }";
+ }
+ O << "\n";
+ }
+
+ O << " break;\n";
+}
void AsmWriterEmitter::run(std::ostream &O) {
EmitSourceFileHeader("Assembly Writer Source Fragment", O);
"/// it returns false.\n"
"bool " << Target.getName() << ClassName
<< "::printInstruction(const MachineInstr *MI) {\n";
- O << " switch (MI->getOpcode()) {\n"
- " default: return false;\n";
std::string Namespace = Target.inst_begin()->second.Namespace;
if (!I->second.AsmString.empty())
Instructions.push_back(AsmWriterInst(I->second, Variant));
- for (unsigned i = 0, e = Instructions.size(); i != e; ++i) {
- O << " case " << Namespace << "::"
- << Instructions[i].CGI->Name << ": ";
- Instructions[i].EmitCode(O);
- O << " break;\n";
+ // If all of the instructions start with a constant string (a very very common
+ // occurance), emit all of the constant strings as a big table lookup instead
+ // of requiring a switch for them.
+ bool AllStartWithString = true;
+
+ for (unsigned i = 0, e = Instructions.size(); i != e; ++i)
+ if (Instructions[i].Operands.empty() ||
+ Instructions[i].Operands[0].OperandType !=
+ AsmWriterOperand::isLiteralTextOperand) {
+ AllStartWithString = false;
+ break;
+ }
+
+ if (AllStartWithString) {
+ // Compute the CodeGenInstruction -> AsmWriterInst mapping. Note that not
+ // all machine instructions are necessarily being printed, so there may be
+ // target instructions not in this map.
+ std::map<const CodeGenInstruction*, AsmWriterInst*> CGIAWIMap;
+ for (unsigned i = 0, e = Instructions.size(); i != e; ++i)
+ CGIAWIMap.insert(std::make_pair(Instructions[i].CGI, &Instructions[i]));
+
+ // Emit a table of constant strings.
+ std::vector<const CodeGenInstruction*> NumberedInstructions;
+ Target.getInstructionsByEnumValue(NumberedInstructions);
+
+ O << " static const char * const OpStrs[] = {\n";
+ for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) {
+ AsmWriterInst *AWI = CGIAWIMap[NumberedInstructions[i]];
+ if (AWI == 0) {
+ // Something not handled by the asmwriter printer.
+ O << " 0,\t// ";
+ } else {
+ O << " \"" << AWI->Operands[0].Str << "\",\t// ";
+ // Nuke the string from the operand list. It is now handled!
+ AWI->Operands.erase(AWI->Operands.begin());
+ }
+ O << NumberedInstructions[i]->TheDef->getName() << "\n";
+ }
+ O << " };\n\n"
+ << " // Emit the opcode for the instruction.\n"
+ << " if (const char *AsmStr = OpStrs[MI->getOpcode()])\n"
+ << " O << AsmStr;\n\n";
}
-
+
+ // Because this is a vector we want to emit from the end. Reverse all of the
+ // elements in the vector.
+ std::reverse(Instructions.begin(), Instructions.end());
+
+ O << " switch (MI->getOpcode()) {\n"
+ " default: return false;\n";
+
+ while (!Instructions.empty())
+ EmitInstructions(Instructions, O);
+
O << " }\n"
" return true;\n"
"}\n";
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