gem5/arch/sparc/isa/base.isa

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////////////////////////////////////////////////////////////////////
//
// Base class for sparc instructions, and some support functions
//
output header {{
union CondCodes
{
struct
{
uint8_t c:1;
uint8_t v:1;
uint8_t z:1;
uint8_t n:1;
};
uint32_t bits;
};
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;
void printReg(std::ostream &os, int reg) const;
};
bool passesCondition(uint32_t codes, uint32_t condition);
}};
def template ROrImmDecode {{
{
return (I ? (SparcStaticInst *)(new %(class_name)sImm(machInst))
: (SparcStaticInst *)(new %(class_name)s(machInst)));
}
}};
let {{
def splitOutImm(code):
matcher = re.compile(r'Rs(?P<rNum>\d)_or_imm(?P<iNum>d{0,2})')
rOrImmMatch = matcher.search(code)
if (rOrImmMatch == None):
return (False, CodeBlock(code), None, '', '')
rString = matcher.sub(r'(?P=rNum)', rOrImmMatch.string)
iString = matcher.sub(r'(?P=iNum)', rOrImmMatch.string)
orig_code = code
code = matcher.sub(r'Rs(?P<rNum>)', orig_code)
imm_code = matcher.sub('imm', orig_code)
return (True, CodeBlock(code), CodeBlock(imm_code), rString, iString)
}};
output decoder {{
void
SparcStaticInst::printReg(std::ostream &os, int reg) const
{
if (reg < FP_Base_DepTag) {
ccprintf(os, "r%d", reg);
}
else {
ccprintf(os, "f%d", reg - FP_Base_DepTag);
}
}
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(uint32_t codes, uint32_t condition)
{
CondCodes condCodes;
condCodes.bits = codes;
switch(condition)
{
case Always:
return true;
case Never:
return false;
case NotEqual:
return !condCodes.z;
case Equal:
return condCodes.z;
case Greater:
return !(condCodes.z | (condCodes.n ^ condCodes.v));
case LessOrEqual:
return condCodes.z | (condCodes.n ^ condCodes.v);
case GreaterOrEqual:
return !(condCodes.n ^ condCodes.v);
case Less:
return (condCodes.n ^ condCodes.v);
case GreaterUnsigned:
return !(condCodes.c | condCodes.z);
case LessOrEqualUnsigned:
return (condCodes.c | condCodes.z);
case CarryClear:
return !condCodes.c;
case CarrySet:
return condCodes.c;
case Positive:
return !condCodes.n;
case Negative:
return condCodes.n;
case OverflowClear:
return !condCodes.v;
case OverflowSet:
return condCodes.v;
}
panic("Tried testing condition nonexistant "
"condition code %d", condition);
}
}};