gem5/arch/sparc/isa/base.isa

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////////////////////////////////////////////////////////////////////
//
// Base class for sparc instructions, and some support functions
//
output header {{
struct condCodes
{
uint8_t c:1;
uint8_t v:1;
uint8_t z:1;
uint8_t n:1;
}
enum condTest
{
Always=0x8,
Never=0x0,
NotEqual=0x9,
Equal=0x1,
Greater=0xA,
LessOrEqual=0x2,
GreaterOrEqual=0xB,
Less=0x3,
GreaterUnsigned=0xC,
LessOrEqualUnsigned=0x4,
CarryClear=0xD,
CarrySet=0x5,
Positive=0xE,
Negative=0x6,
OverflowClear=0xF,
OverflowSet=0x7
}
/**
* Base class for all SPARC static instructions.
*/
class SparcStaticInst : public StaticInst
{
protected:
// Constructor.
SparcStaticInst(const char *mnem,
MachInst _machInst, OpClass __opClass)
: StaticInst(mnem, _machInst, __opClass)
{
}
std::string generateDisassembly(Addr pc,
const SymbolTable *symtab) const;
};
bool passesCondition(condCodes codes, condTest condition);
}};
output decoder {{
std::string SparcStaticInst::generateDisassembly(Addr pc,
const SymbolTable *symtab) const
{
std::stringstream ss;
ccprintf(ss, "%-10s ", mnemonic);
// just print the first two source regs... if there's
// a third one, it's a read-modify-write dest (Rc),
// e.g. for CMOVxx
if(_numSrcRegs > 0)
{
printReg(ss, _srcRegIdx[0]);
}
if(_numSrcRegs > 1)
{
ss << ",";
printReg(ss, _srcRegIdx[1]);
}
// just print the first dest... if there's a second one,
// it's generally implicit
if(_numDestRegs > 0)
{
if(_numSrcRegs > 0)
ss << ",";
printReg(ss, _destRegIdx[0]);
}
return ss.str();
}
bool passesCondition(condCodes codes, condTest condition)
{
switch(condition)
{
case Always:
return true;
case Never:
return false;
case NotEqual:
return !codes.z;
case Equal:
return codes.z;
case Greater:
return !(codes.z | (codes.n ^ codes.v));
case LessOrEqual:
return codes.z | (codes.n ^ codes.v);
case GreaterOrEqual:
return !(codes.n ^ codes.v);
case Less:
return (codes.n ^ codes.v);
case GreaterUnsigned:
return !(codes.c | codes.z);
case LessOrEqualUnsigned:
return (codes.c | codes.z);
case CarryClear:
return !codes.c;
case CarrySet:
return codes.c;
case Positive:
return !codes.n;
case Negative:
return codes.n;
case OverflowClear:
return !codes.v;
case OverflowSet:
return codes.v;
}
}
}};