DirectXShaderCompiler/utils/TableGen/AsmWriterInst.cpp

201 строка
7.1 KiB
C++

//===- AsmWriterInst.h - Classes encapsulating a printable inst -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// These classes implement a parser for assembly strings.
//
//===----------------------------------------------------------------------===//
#include "AsmWriterInst.h"
#include "CodeGenTarget.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/TableGen/Error.h"
#include "llvm/TableGen/Record.h"
using namespace llvm;
static bool isIdentChar(char C) {
return (C >= 'a' && C <= 'z') ||
(C >= 'A' && C <= 'Z') ||
(C >= '0' && C <= '9') ||
C == '_';
}
std::string AsmWriterOperand::getCode() const {
if (OperandType == isLiteralTextOperand) {
if (Str.size() == 1)
return "O << '" + Str + "'; ";
return "O << \"" + Str + "\"; ";
}
if (OperandType == isLiteralStatementOperand)
return Str;
std::string Result = Str + "(MI";
if (MIOpNo != ~0U)
Result += ", " + utostr(MIOpNo);
if (PassSubtarget)
Result += ", STI";
Result += ", O";
if (!MiModifier.empty())
Result += ", \"" + MiModifier + '"';
return Result + "); ";
}
/// ParseAsmString - Parse the specified Instruction's AsmString into this
/// AsmWriterInst.
///
AsmWriterInst::AsmWriterInst(const CodeGenInstruction &CGI, unsigned Variant,
unsigned PassSubtarget) {
this->CGI = &CGI;
// NOTE: Any extensions to this code need to be mirrored in the
// AsmPrinter::printInlineAsm code that executes as compile time (assuming
// that inline asm strings should also get the new feature)!
std::string AsmString = CGI.FlattenAsmStringVariants(CGI.AsmString, Variant);
std::string::size_type LastEmitted = 0;
while (LastEmitted != AsmString.size()) {
std::string::size_type DollarPos =
AsmString.find_first_of("$\\", LastEmitted);
if (DollarPos == std::string::npos) DollarPos = AsmString.size();
// Emit a constant string fragment.
if (DollarPos != LastEmitted) {
for (; LastEmitted != DollarPos; ++LastEmitted)
switch (AsmString[LastEmitted]) {
case '\n':
AddLiteralString("\\n");
break;
case '\t':
AddLiteralString("\\t");
break;
case '"':
AddLiteralString("\\\"");
break;
case '\\':
AddLiteralString("\\\\");
break;
default:
AddLiteralString(std::string(1, AsmString[LastEmitted]));
break;
}
} else if (AsmString[DollarPos] == '\\') {
if (DollarPos+1 != AsmString.size()) {
if (AsmString[DollarPos+1] == 'n') {
AddLiteralString("\\n");
} else if (AsmString[DollarPos+1] == 't') {
AddLiteralString("\\t");
} else if (std::string("${|}\\").find(AsmString[DollarPos+1])
!= std::string::npos) {
AddLiteralString(std::string(1, AsmString[DollarPos+1]));
} else {
PrintFatalError("Non-supported escaped character found in instruction '" +
CGI.TheDef->getName() + "'!");
}
LastEmitted = DollarPos+2;
continue;
}
} else if (DollarPos+1 != AsmString.size() &&
AsmString[DollarPos+1] == '$') {
AddLiteralString("$"); // "$$" -> $
LastEmitted = DollarPos+2;
} else {
// Get the name of the variable.
std::string::size_type VarEnd = DollarPos+1;
// handle ${foo}bar as $foo by detecting whether the character following
// the dollar sign is a curly brace. If so, advance VarEnd and DollarPos
// so the variable name does not contain the leading curly brace.
bool hasCurlyBraces = false;
if (VarEnd < AsmString.size() && '{' == AsmString[VarEnd]) {
hasCurlyBraces = true;
++DollarPos;
++VarEnd;
}
while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd]))
++VarEnd;
std::string VarName(AsmString.begin()+DollarPos+1,
AsmString.begin()+VarEnd);
// Modifier - Support ${foo:modifier} syntax, where "modifier" is passed
// into printOperand. Also support ${:feature}, which is passed into
// PrintSpecial.
std::string Modifier;
// In order to avoid starting the next string at the terminating curly
// brace, advance the end position past it if we found an opening curly
// brace.
if (hasCurlyBraces) {
if (VarEnd >= AsmString.size())
PrintFatalError("Reached end of string before terminating curly brace in '"
+ CGI.TheDef->getName() + "'");
// Look for a modifier string.
if (AsmString[VarEnd] == ':') {
++VarEnd;
if (VarEnd >= AsmString.size())
PrintFatalError("Reached end of string before terminating curly brace in '"
+ CGI.TheDef->getName() + "'");
unsigned ModifierStart = VarEnd;
while (VarEnd < AsmString.size() && isIdentChar(AsmString[VarEnd]))
++VarEnd;
Modifier = std::string(AsmString.begin()+ModifierStart,
AsmString.begin()+VarEnd);
if (Modifier.empty())
PrintFatalError("Bad operand modifier name in '"+ CGI.TheDef->getName() + "'");
}
if (AsmString[VarEnd] != '}')
PrintFatalError("Variable name beginning with '{' did not end with '}' in '"
+ CGI.TheDef->getName() + "'");
++VarEnd;
}
if (VarName.empty() && Modifier.empty())
PrintFatalError("Stray '$' in '" + CGI.TheDef->getName() +
"' asm string, maybe you want $$?");
if (VarName.empty()) {
// Just a modifier, pass this into PrintSpecial.
Operands.emplace_back("PrintSpecial", ~0U, ~0U, Modifier,
PassSubtarget);
} else {
// Otherwise, normal operand.
unsigned OpNo = CGI.Operands.getOperandNamed(VarName);
CGIOperandList::OperandInfo OpInfo = CGI.Operands[OpNo];
unsigned MIOp = OpInfo.MIOperandNo;
Operands.emplace_back(OpInfo.PrinterMethodName, OpNo, MIOp, Modifier,
PassSubtarget);
}
LastEmitted = VarEnd;
}
}
Operands.emplace_back("return;", AsmWriterOperand::isLiteralStatementOperand);
}
/// 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;
MismatchOperand = i;
}
}
return MismatchOperand;
}