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llvm-6502/lib/Target/SparcV9/SparcV9CodeEmitter.cpp
Misha Brukman 103f0c3472 Added some optimizations: 
* Generate a single BA instead of 6-instruction JUMP if possible
  (this occurs both in the creation and overwriting of the stub code)
* If possible, rewrite the ORIGINAL call to call the generated function
  directly, thus bypassing the stub entirely

Also added some statistics on how often calls are overwritten and how often the
CompilationCallback is invoked.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8376 91177308-0d34-0410-b5e6-96231b3b80d8
2003-09-05 22:59:31 +00:00

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//===-- SparcV9CodeEmitter.cpp --------------------------------------------===//
//
// FIXME: document
//
//===----------------------------------------------------------------------===//
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/PassManager.h"
#include "llvm/CodeGen/MachineCodeEmitter.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFunctionInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetData.h"
#include "Support/Debug.h"
#include "Support/hash_set"
#include "Support/Statistic.h"
#include "SparcInternals.h"
#include "SparcV9CodeEmitter.h"
#include "Config/alloca.h"
namespace {
Statistic<> OverwrittenCalls("call-ovwr", "Number of over-written calls");
Statistic<> UnmodifiedCalls("call-skip", "Number of unmodified calls");
Statistic<> CallbackCalls("callback", "Number CompilationCallback() calls");
}
bool UltraSparc::addPassesToEmitMachineCode(FunctionPassManager &PM,
MachineCodeEmitter &MCE) {
MachineCodeEmitter *M = &MCE;
DEBUG(M = MachineCodeEmitter::createFilePrinterEmitter(MCE));
PM.add(new SparcV9CodeEmitter(*this, *M));
PM.add(createMachineCodeDestructionPass()); // Free stuff no longer needed
return false;
}
namespace {
class JITResolver {
SparcV9CodeEmitter &SparcV9;
MachineCodeEmitter &MCE;
/// LazyCodeGenMap - Keep track of call sites for functions that are to be
/// lazily resolved.
///
std::map<uint64_t, Function*> LazyCodeGenMap;
/// LazyResolverMap - Keep track of the lazy resolver created for a
/// particular function so that we can reuse them if necessary.
///
std::map<Function*, uint64_t> LazyResolverMap;
public:
enum CallType { ShortCall, FarCall };
private:
/// We need to keep track of whether we used a simple call or a far call
/// (many instructions) in sequence. This means we need to keep track of
/// what type of stub we generate.
static std::map<uint64_t, CallType> LazyCallFlavor;
public:
JITResolver(SparcV9CodeEmitter &V9,
MachineCodeEmitter &mce) : SparcV9(V9), MCE(mce) {}
uint64_t getLazyResolver(Function *F);
uint64_t addFunctionReference(uint64_t Address, Function *F);
void deleteFunctionReference(uint64_t Address);
void addCallFlavor(uint64_t Address, CallType Flavor) {
LazyCallFlavor[Address] = Flavor;
}
// Utility functions for accessing data from static callback
uint64_t getCurrentPCValue() {
return MCE.getCurrentPCValue();
}
unsigned getBinaryCodeForInstr(MachineInstr &MI) {
return SparcV9.getBinaryCodeForInstr(MI);
}
inline uint64_t insertFarJumpAtAddr(int64_t Value, uint64_t Addr);
private:
uint64_t emitStubForFunction(Function *F);
static void SaveRegisters(uint64_t DoubleFP[], uint64_t &FSR,
uint64_t &FPRS, uint64_t &CCR);
static void RestoreRegisters(uint64_t DoubleFP[], uint64_t &FSR,
uint64_t &FPRS, uint64_t &CCR);
static void CompilationCallback();
uint64_t resolveFunctionReference(uint64_t RetAddr);
};
JITResolver *TheJITResolver;
std::map<uint64_t, JITResolver::CallType> JITResolver::LazyCallFlavor;
}
/// addFunctionReference - This method is called when we need to emit the
/// address of a function that has not yet been emitted, so we don't know the
/// address. Instead, we emit a call to the CompilationCallback method, and
/// keep track of where we are.
///
uint64_t JITResolver::addFunctionReference(uint64_t Address, Function *F) {
LazyCodeGenMap[Address] = F;
return (intptr_t)&JITResolver::CompilationCallback;
}
/// deleteFunctionReference - If we are emitting a far call, we already added a
/// reference to the function, but it is now incorrect, since the address to the
/// JIT resolver is too far away to be a simple call instruction. This is used
/// to remove the address from the map.
///
void JITResolver::deleteFunctionReference(uint64_t Address) {
std::map<uint64_t, Function*>::iterator I = LazyCodeGenMap.find(Address);
assert(I != LazyCodeGenMap.end() && "Not in map!");
LazyCodeGenMap.erase(I);
}
uint64_t JITResolver::resolveFunctionReference(uint64_t RetAddr) {
std::map<uint64_t, Function*>::iterator I = LazyCodeGenMap.find(RetAddr);
assert(I != LazyCodeGenMap.end() && "Not in map!");
Function *F = I->second;
LazyCodeGenMap.erase(I);
return MCE.forceCompilationOf(F);
}
uint64_t JITResolver::getLazyResolver(Function *F) {
std::map<Function*, uint64_t>::iterator I = LazyResolverMap.lower_bound(F);
if (I != LazyResolverMap.end() && I->first == F) return I->second;
//std::cerr << "Getting lazy resolver for : " << ((Value*)F)->getName() << "\n";
uint64_t Stub = emitStubForFunction(F);
LazyResolverMap.insert(I, std::make_pair(F, Stub));
return Stub;
}
uint64_t JITResolver::insertFarJumpAtAddr(int64_t Target, uint64_t Addr) {
static const unsigned
o6 = SparcIntRegClass::o6, g0 = SparcIntRegClass::g0,
g1 = SparcIntRegClass::g1, g5 = SparcIntRegClass::g5;
MachineInstr* BinaryCode[] = {
//
// Get address to branch into %g1, using %g5 as a temporary
//
// sethi %uhi(Target), %g5 ;; get upper 22 bits of Target into %g5
BuildMI(V9::SETHI, 2).addSImm(Target >> 42).addReg(g5),
// or %g5, %ulo(Target), %g5 ;; get 10 lower bits of upper word into %g5
BuildMI(V9::ORi, 3).addReg(g5).addSImm((Target >> 32) & 0x03ff).addReg(g5),
// sllx %g5, 32, %g5 ;; shift those 10 bits to the upper word
BuildMI(V9::SLLXi6, 3).addReg(g5).addSImm(32).addReg(g5),
// sethi %hi(Target), %g1 ;; extract bits 10-31 into the dest reg
BuildMI(V9::SETHI, 2).addSImm((Target >> 10) & 0x03fffff).addReg(g1),
// or %g5, %g1, %g1 ;; get upper word (in %g5) into %g1
BuildMI(V9::ORr, 3).addReg(g5).addReg(g1).addReg(g1),
// or %g1, %lo(Target), %g1 ;; get lowest 10 bits of Target into %g1
BuildMI(V9::ORi, 3).addReg(g1).addSImm(Target & 0x03ff).addReg(g1),
// jmpl %g1, %g0, %g0 ;; indirect branch on %g1
BuildMI(V9::JMPLRETr, 3).addReg(g1).addReg(g0).addReg(g0),
// nop ;; delay slot
BuildMI(V9::NOP, 0)
};
for (unsigned i=0, e=sizeof(BinaryCode)/sizeof(BinaryCode[0]); i!=e; ++i) {
*((unsigned*)(intptr_t)Addr) = getBinaryCodeForInstr(*BinaryCode[i]);
delete BinaryCode[i];
Addr += 4;
}
return Addr;
}
void JITResolver::SaveRegisters(uint64_t DoubleFP[], uint64_t &FSR,
uint64_t &FPRS, uint64_t &CCR) {
#if defined(sparc) || defined(__sparc__) || defined(__sparcv9)
#if 0
__asm__ __volatile__ (// Save condition-code registers
"stx %%fsr, %0;\n\t"
"rd %%fprs, %1;\n\t"
"rd %%ccr, %2;\n\t"
: "=m"(FSR), "=r"(FPRS), "=r"(CCR));
#endif
// GCC says: `asm' only allows up to thirty parameters!
__asm__ __volatile__ (// Save Single/Double FP registers, part 1
"std %%f0, %0;\n\t" "std %%f2, %1;\n\t"
"std %%f4, %2;\n\t" "std %%f6, %3;\n\t"
"std %%f8, %4;\n\t" "std %%f10, %5;\n\t"
"std %%f12, %6;\n\t" "std %%f14, %7;\n\t"
"std %%f16, %8;\n\t" "std %%f18, %9;\n\t"
"std %%f20, %10;\n\t" "std %%f22, %11;\n\t"
"std %%f24, %12;\n\t" "std %%f26, %13;\n\t"
"std %%f28, %14;\n\t" "std %%f30, %15;\n\t"
: "=m"(DoubleFP[ 0]), "=m"(DoubleFP[ 1]),
"=m"(DoubleFP[ 2]), "=m"(DoubleFP[ 3]),
"=m"(DoubleFP[ 4]), "=m"(DoubleFP[ 5]),
"=m"(DoubleFP[ 6]), "=m"(DoubleFP[ 7]),
"=m"(DoubleFP[ 8]), "=m"(DoubleFP[ 9]),
"=m"(DoubleFP[10]), "=m"(DoubleFP[11]),
"=m"(DoubleFP[12]), "=m"(DoubleFP[13]),
"=m"(DoubleFP[14]), "=m"(DoubleFP[15]));
__asm__ __volatile__ (// Save Double FP registers, part 2
"std %%f32, %0;\n\t" "std %%f34, %1;\n\t"
"std %%f36, %2;\n\t" "std %%f38, %3;\n\t"
"std %%f40, %4;\n\t" "std %%f42, %5;\n\t"
"std %%f44, %6;\n\t" "std %%f46, %7;\n\t"
"std %%f48, %8;\n\t" "std %%f50, %9;\n\t"
"std %%f52, %10;\n\t" "std %%f54, %11;\n\t"
"std %%f56, %12;\n\t" "std %%f58, %13;\n\t"
"std %%f60, %14;\n\t" "std %%f62, %15;\n\t"
: "=m"(DoubleFP[16]), "=m"(DoubleFP[17]),
"=m"(DoubleFP[18]), "=m"(DoubleFP[19]),
"=m"(DoubleFP[20]), "=m"(DoubleFP[21]),
"=m"(DoubleFP[22]), "=m"(DoubleFP[23]),
"=m"(DoubleFP[24]), "=m"(DoubleFP[25]),
"=m"(DoubleFP[26]), "=m"(DoubleFP[27]),
"=m"(DoubleFP[28]), "=m"(DoubleFP[29]),
"=m"(DoubleFP[30]), "=m"(DoubleFP[31]));
#endif
}
void JITResolver::RestoreRegisters(uint64_t DoubleFP[], uint64_t &FSR,
uint64_t &FPRS, uint64_t &CCR)
{
#if defined(sparc) || defined(__sparc__) || defined(__sparcv9)
#if 0
__asm__ __volatile__ (// Restore condition-code registers
"ldx %0, %%fsr;\n\t"
"wr %1, 0, %%fprs;\n\t"
"wr %2, 0, %%ccr;\n\t"
:: "m"(FSR), "r"(FPRS), "r"(CCR));
#endif
// GCC says: `asm' only allows up to thirty parameters!
__asm__ __volatile__ (// Restore Single/Double FP registers, part 1
"ldd %0, %%f0;\n\t" "ldd %1, %%f2;\n\t"
"ldd %2, %%f4;\n\t" "ldd %3, %%f6;\n\t"
"ldd %4, %%f8;\n\t" "ldd %5, %%f10;\n\t"
"ldd %6, %%f12;\n\t" "ldd %7, %%f14;\n\t"
"ldd %8, %%f16;\n\t" "ldd %9, %%f18;\n\t"
"ldd %10, %%f20;\n\t" "ldd %11, %%f22;\n\t"
"ldd %12, %%f24;\n\t" "ldd %13, %%f26;\n\t"
"ldd %14, %%f28;\n\t" "ldd %15, %%f30;\n\t"
:: "m"(DoubleFP[0]), "m"(DoubleFP[1]),
"m"(DoubleFP[2]), "m"(DoubleFP[3]),
"m"(DoubleFP[4]), "m"(DoubleFP[5]),
"m"(DoubleFP[6]), "m"(DoubleFP[7]),
"m"(DoubleFP[8]), "m"(DoubleFP[9]),
"m"(DoubleFP[10]), "m"(DoubleFP[11]),
"m"(DoubleFP[12]), "m"(DoubleFP[13]),
"m"(DoubleFP[14]), "m"(DoubleFP[15]));
__asm__ __volatile__ (// Restore Double FP registers, part 2
"ldd %0, %%f32;\n\t" "ldd %1, %%f34;\n\t"
"ldd %2, %%f36;\n\t" "ldd %3, %%f38;\n\t"
"ldd %4, %%f40;\n\t" "ldd %5, %%f42;\n\t"
"ldd %6, %%f44;\n\t" "ldd %7, %%f46;\n\t"
"ldd %8, %%f48;\n\t" "ldd %9, %%f50;\n\t"
"ldd %10, %%f52;\n\t" "ldd %11, %%f54;\n\t"
"ldd %12, %%f56;\n\t" "ldd %13, %%f58;\n\t"
"ldd %14, %%f60;\n\t" "ldd %15, %%f62;\n\t"
:: "m"(DoubleFP[16]), "m"(DoubleFP[17]),
"m"(DoubleFP[18]), "m"(DoubleFP[19]),
"m"(DoubleFP[20]), "m"(DoubleFP[21]),
"m"(DoubleFP[22]), "m"(DoubleFP[23]),
"m"(DoubleFP[24]), "m"(DoubleFP[25]),
"m"(DoubleFP[26]), "m"(DoubleFP[27]),
"m"(DoubleFP[28]), "m"(DoubleFP[29]),
"m"(DoubleFP[30]), "m"(DoubleFP[31]));
#endif
}
void JITResolver::CompilationCallback() {
// Local space to save double registers
uint64_t DoubleFP[32];
uint64_t FSR, FPRS, CCR;
SaveRegisters(DoubleFP, FSR, FPRS, CCR);
++CallbackCalls;
uint64_t CameFrom = (uint64_t)(intptr_t)__builtin_return_address(0);
uint64_t CameFrom1 = (uint64_t)(intptr_t)__builtin_return_address(1);
int64_t Target = (int64_t)TheJITResolver->resolveFunctionReference(CameFrom);
DEBUG(std::cerr << "In callback! Addr=0x" << std::hex << CameFrom << "\n");
register int64_t returnAddr = 0;
#if defined(sparc) || defined(__sparc__) || defined(__sparcv9)
__asm__ __volatile__ ("add %%i7, %%g0, %0" : "=r" (returnAddr) : );
DEBUG(std::cerr << "Read i7 (return addr) = "
<< std::hex << returnAddr << ", value: "
<< std::hex << *(unsigned*)returnAddr << "\n");
#endif
// If we can rewrite the ORIGINAL caller, we eliminate the whole need for a
// trampoline function stub!!
unsigned OrigCallInst = *((unsigned*)(intptr_t)CameFrom1);
int64_t OrigTarget = (Target-CameFrom1) >> 2;
if ((OrigCallInst & (1 << 30)) &&
(OrigTarget <= (1 << 30) && OrigTarget >= -(1 << 30)))
{
// The original call instruction was CALL <immed>, which means we can
// overwrite it directly, since the offset will fit into 30 bits
MachineInstr *C = BuildMI(V9::CALL, 1).addSImm(OrigTarget);
*((unsigned*)(intptr_t)CameFrom1)=TheJITResolver->getBinaryCodeForInstr(*C);
delete C;
++OverwrittenCalls;
} else {
++UnmodifiedCalls;
}
// Rewrite the call target so that we don't fault every time we execute it.
//
static const unsigned o6 = SparcIntRegClass::o6;
// Subtract enough to overwrite up to the 'save' instruction
// This depends on whether we made a short call (1 instruction) or the
// farCall (7 instructions)
uint64_t Offset = (LazyCallFlavor[CameFrom] == ShortCall) ? 4 : 28;
uint64_t CodeBegin = CameFrom - Offset;
// FIXME FIXME FIXME FIXME: __builtin_frame_address doesn't work if frame
// pointer elimination has been performed. Having a variable sized alloca
// disables frame pointer elimination currently, even if it's dead. This is
// a gross hack.
alloca(42+Offset);
// FIXME FIXME FIXME FIXME
// Make sure that what we're about to overwrite is indeed "save"
MachineInstr *SV =BuildMI(V9::SAVEi, 3).addReg(o6).addSImm(-192).addReg(o6);
unsigned SaveInst = TheJITResolver->getBinaryCodeForInstr(*SV);
delete SV;
unsigned CodeInMem = *(unsigned*)(intptr_t)CodeBegin;
if (CodeInMem != SaveInst) {
std::cerr << "About to overwrite smthg not a save instr!";
abort();
}
DEBUG(std::cerr << "Emitting a jump to 0x" << std::hex << Target << "\n");
// If the target function is close enough to fit into the 19bit disp of
// BA, we should use this version, as its much cheaper to generate.
int64_t BranchTarget = (Target-CodeBegin) >> 2;
if (BranchTarget >= (1 << 19) || BranchTarget <= -(1 << 19)) {
TheJITResolver->insertFarJumpAtAddr(Target, CodeBegin);
} else {
// ba <target>
MachineInstr *I = BuildMI(V9::BA, 1).addSImm(BranchTarget);
*((unsigned*)(intptr_t)CodeBegin) =
TheJITResolver->getBinaryCodeForInstr(*I);
CodeBegin += 4;
delete I;
// nop
I = BuildMI(V9::NOP, 0);
*((unsigned*)(intptr_t)CodeBegin) =
TheJITResolver->getBinaryCodeForInstr(*I);
delete I;
}
RestoreRegisters(DoubleFP, FSR, FPRS, CCR);
// Change the return address to reexecute the restore, then the jump. However,
// we can't just modify %i7 here, because we return to the function that will
// restore the floating-point registers for us. Thus, we just return the value
// we want it to be, and the parent will take care of setting %i7 correctly.
DEBUG(std::cerr << "Callback returning to: 0x"
<< std::hex << (CameFrom-Offset-12) << "\n");
#if defined(sparc) || defined(__sparc__) || defined(__sparcv9)
__asm__ __volatile__ ("sub %%i7, %0, %%i7" : : "r" (Offset+12));
#endif
}
/// emitStubForFunction - This method is used by the JIT when it needs to emit
/// the address of a function for a function whose code has not yet been
/// generated. In order to do this, it generates a stub which jumps to the lazy
/// function compiler, which will eventually get fixed to call the function
/// directly.
///
uint64_t JITResolver::emitStubForFunction(Function *F) {
MCE.startFunctionStub(*F, 44);
DEBUG(std::cerr << "Emitting stub at addr: 0x"
<< std::hex << MCE.getCurrentPCValue() << "\n");
unsigned o6 = SparcIntRegClass::o6, g0 = SparcIntRegClass::g0;
// restore %g0, 0, %g0
MachineInstr *R = BuildMI(V9::RESTOREi, 3).addMReg(g0).addSImm(0)
.addMReg(g0, MOTy::Def);
SparcV9.emitWord(SparcV9.getBinaryCodeForInstr(*R));
delete R;
// save %sp, -192, %sp
MachineInstr *SV = BuildMI(V9::SAVEi, 3).addReg(o6).addSImm(-192).addReg(o6);
SparcV9.emitWord(SparcV9.getBinaryCodeForInstr(*SV));
delete SV;
int64_t CurrPC = MCE.getCurrentPCValue();
int64_t Addr = (int64_t)addFunctionReference(CurrPC, F);
int64_t CallTarget = (Addr-CurrPC) >> 2;
if (CallTarget >= (1 << 29) || CallTarget <= -(1 << 29)) {
// Since this is a far call, the actual address of the call is shifted
// by the number of instructions it takes to calculate the exact address
deleteFunctionReference(CurrPC);
SparcV9.emitFarCall(Addr, F);
} else {
// call CallTarget ;; invoke the callback
MachineInstr *Call = BuildMI(V9::CALL, 1).addSImm(CallTarget);
SparcV9.emitWord(SparcV9.getBinaryCodeForInstr(*Call));
delete Call;
// nop ;; call delay slot
MachineInstr *Nop = BuildMI(V9::NOP, 0);
SparcV9.emitWord(SparcV9.getBinaryCodeForInstr(*Nop));
delete Nop;
addCallFlavor(CurrPC, ShortCall);
}
SparcV9.emitWord(0xDEADBEEF); // marker so that we know it's really a stub
return (intptr_t)MCE.finishFunctionStub(*F)+4; /* 1 instr past the restore */
}
SparcV9CodeEmitter::SparcV9CodeEmitter(TargetMachine &tm,
MachineCodeEmitter &M): TM(tm), MCE(M)
{
TheJITResolver = new JITResolver(*this, M);
}
SparcV9CodeEmitter::~SparcV9CodeEmitter() {
delete TheJITResolver;
}
void SparcV9CodeEmitter::emitWord(unsigned Val) {
// Output the constant in big endian byte order...
unsigned byteVal;
for (int i = 3; i >= 0; --i) {
byteVal = Val >> 8*i;
MCE.emitByte(byteVal & 255);
}
}
unsigned
SparcV9CodeEmitter::getRealRegNum(unsigned fakeReg,
MachineInstr &MI) {
const TargetRegInfo &RI = TM.getRegInfo();
unsigned regClass, regType = RI.getRegType(fakeReg);
// At least map fakeReg into its class
fakeReg = RI.getClassRegNum(fakeReg, regClass);
switch (regClass) {
case UltraSparcRegInfo::IntRegClassID: {
// Sparc manual, p31
static const unsigned IntRegMap[] = {
// "o0", "o1", "o2", "o3", "o4", "o5", "o7",
8, 9, 10, 11, 12, 13, 15,
// "l0", "l1", "l2", "l3", "l4", "l5", "l6", "l7",
16, 17, 18, 19, 20, 21, 22, 23,
// "i0", "i1", "i2", "i3", "i4", "i5", "i6", "i7",
24, 25, 26, 27, 28, 29, 30, 31,
// "g0", "g1", "g2", "g3", "g4", "g5", "g6", "g7",
0, 1, 2, 3, 4, 5, 6, 7,
// "o6"
14
};
return IntRegMap[fakeReg];
break;
}
case UltraSparcRegInfo::FloatRegClassID: {
DEBUG(std::cerr << "FP reg: " << fakeReg << "\n");
if (regType == UltraSparcRegInfo::FPSingleRegType) {
// only numbered 0-31, hence can already fit into 5 bits (and 6)
DEBUG(std::cerr << "FP single reg, returning: " << fakeReg << "\n");
} else if (regType == UltraSparcRegInfo::FPDoubleRegType) {
// FIXME: This assumes that we only have 5-bit register fiels!
// From Sparc Manual, page 40.
// The bit layout becomes: b[4], b[3], b[2], b[1], b[5]
fakeReg |= (fakeReg >> 5) & 1;
fakeReg &= 0x1f;
DEBUG(std::cerr << "FP double reg, returning: " << fakeReg << "\n");
}
return fakeReg;
}
case UltraSparcRegInfo::IntCCRegClassID: {
/* xcc, icc, ccr */
static const unsigned IntCCReg[] = { 6, 4, 2 };
assert(fakeReg < sizeof(IntCCReg)/sizeof(IntCCReg[0])
&& "CC register out of bounds for IntCCReg map");
DEBUG(std::cerr << "IntCC reg: " << IntCCReg[fakeReg] << "\n");
return IntCCReg[fakeReg];
}
case UltraSparcRegInfo::FloatCCRegClassID: {
/* These are laid out %fcc0 - %fcc3 => 0 - 3, so are correct */
DEBUG(std::cerr << "FP CC reg: " << fakeReg << "\n");
return fakeReg;
}
default:
assert(0 && "Invalid unified register number in getRegType");
return fakeReg;
}
}
// WARNING: if the call used the delay slot to do meaningful work, that's not
// being accounted for, and the behavior will be incorrect!!
inline void SparcV9CodeEmitter::emitFarCall(uint64_t Target, Function *F) {
static const unsigned o6 = SparcIntRegClass::o6,
o7 = SparcIntRegClass::o7, g0 = SparcIntRegClass::g0,
g1 = SparcIntRegClass::g1, g5 = SparcIntRegClass::g5;
MachineInstr* BinaryCode[] = {
//
// Get address to branch into %g1, using %g5 as a temporary
//
// sethi %uhi(Target), %g5 ;; get upper 22 bits of Target into %g5
BuildMI(V9::SETHI, 2).addSImm(Target >> 42).addReg(g5),
// or %g5, %ulo(Target), %g5 ;; get 10 lower bits of upper word into %1
BuildMI(V9::ORi, 3).addReg(g5).addSImm((Target >> 32) & 0x03ff).addReg(g5),
// sllx %g5, 32, %g5 ;; shift those 10 bits to the upper word
BuildMI(V9::SLLXi6, 3).addReg(g5).addSImm(32).addReg(g5),
// sethi %hi(Target), %g1 ;; extract bits 10-31 into the dest reg
BuildMI(V9::SETHI, 2).addSImm((Target >> 10) & 0x03fffff).addReg(g1),
// or %g5, %g1, %g1 ;; get upper word (in %g5) into %g1
BuildMI(V9::ORr, 3).addReg(g5).addReg(g1).addReg(g1),
// or %g1, %lo(Target), %g1 ;; get lowest 10 bits of Target into %g1
BuildMI(V9::ORi, 3).addReg(g1).addSImm(Target & 0x03ff).addReg(g1),
// jmpl %g1, %g0, %o7 ;; indirect call on %g1
BuildMI(V9::JMPLRETr, 3).addReg(g1).addReg(g0).addReg(o7),
// nop ;; delay slot
BuildMI(V9::NOP, 0)
};
for (unsigned i=0, e=sizeof(BinaryCode)/sizeof(BinaryCode[0]); i!=e; ++i) {
// This is where we save the return address in the LazyResolverMap!!
if (i == 6 && F != 0) { // Do this right before the JMPL
uint64_t CurrPC = MCE.getCurrentPCValue();
TheJITResolver->addFunctionReference(CurrPC, F);
// Remember that this is a far call, to subtract appropriate offset later
TheJITResolver->addCallFlavor(CurrPC, JITResolver::FarCall);
}
emitWord(getBinaryCodeForInstr(*BinaryCode[i]));
delete BinaryCode[i];
}
}
int64_t SparcV9CodeEmitter::getMachineOpValue(MachineInstr &MI,
MachineOperand &MO) {
int64_t rv = 0; // Return value; defaults to 0 for unhandled cases
// or things that get fixed up later by the JIT.
if (MO.isVirtualRegister()) {
std::cerr << "ERROR: virtual register found in machine code.\n";
abort();
} else if (MO.isPCRelativeDisp()) {
DEBUG(std::cerr << "PCRelativeDisp: ");
Value *V = MO.getVRegValue();
if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) {
DEBUG(std::cerr << "Saving reference to BB (VReg)\n");
unsigned* CurrPC = (unsigned*)(intptr_t)MCE.getCurrentPCValue();
BBRefs.push_back(std::make_pair(BB, std::make_pair(CurrPC, &MI)));
} else if (const Constant *C = dyn_cast<Constant>(V)) {
if (ConstantMap.find(C) != ConstantMap.end()) {
rv = (int64_t)MCE.getConstantPoolEntryAddress(ConstantMap[C]);
DEBUG(std::cerr << "const: 0x" << std::hex << rv << "\n");
} else {
std::cerr << "ERROR: constant not in map:" << MO << "\n";
abort();
}
} else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
// same as MO.isGlobalAddress()
DEBUG(std::cerr << "GlobalValue: ");
// external function calls, etc.?
if (Function *F = dyn_cast<Function>(GV)) {
DEBUG(std::cerr << "Function: ");
if (F->isExternal()) {
// Sparc backend broken: this MO should be `ExternalSymbol'
rv = (int64_t)MCE.getGlobalValueAddress(F->getName());
} else {
rv = (int64_t)MCE.getGlobalValueAddress(F);
}
if (rv == 0) {
DEBUG(std::cerr << "not yet generated\n");
// Function has not yet been code generated!
TheJITResolver->addFunctionReference(MCE.getCurrentPCValue(), F);
// Delayed resolution...
rv = TheJITResolver->getLazyResolver(F);
} else {
DEBUG(std::cerr << "already generated: 0x" << std::hex << rv << "\n");
}
} else {
rv = (int64_t)MCE.getGlobalValueAddress(GV);
if (rv == 0) {
if (Constant *C = ConstantPointerRef::get(GV)) {
if (ConstantMap.find(C) != ConstantMap.end()) {
rv = MCE.getConstantPoolEntryAddress(ConstantMap[C]);
} else {
std::cerr << "Constant: 0x" << std::hex << (intptr_t)C
<< ", " << *V << " not found in ConstantMap!\n";
abort();
}
}
}
DEBUG(std::cerr << "Global addr: 0x" << std::hex << rv << "\n");
}
// The real target of the call is Addr = PC + (rv * 4)
// So undo that: give the instruction (Addr - PC) / 4
if (MI.getOpcode() == V9::CALL) {
int64_t CurrPC = MCE.getCurrentPCValue();
DEBUG(std::cerr << "rv addr: 0x" << std::hex << rv << "\n"
<< "curr PC: 0x" << std::hex << CurrPC << "\n");
int64_t CallInstTarget = (rv - CurrPC) >> 2;
if (CallInstTarget >= (1<<29) || CallInstTarget <= -(1<<29)) {
DEBUG(std::cerr << "Making far call!\n");
// addresss is out of bounds for the 30-bit call,
// make an indirect jump-and-link
emitFarCall(rv);
// this invalidates the instruction so that the call with an incorrect
// address will not be emitted
rv = 0;
} else {
// The call fits into 30 bits, so just return the corrected address
rv = CallInstTarget;
}
DEBUG(std::cerr << "returning addr: 0x" << rv << "\n");
}
} else {
std::cerr << "ERROR: PC relative disp unhandled:" << MO << "\n";
abort();
}
} else if (MO.isPhysicalRegister() ||
MO.getType() == MachineOperand::MO_CCRegister)
{
// This is necessary because the Sparc backend doesn't actually lay out
// registers in the real fashion -- it skips those that it chooses not to
// allocate, i.e. those that are the FP, SP, etc.
unsigned fakeReg = MO.getAllocatedRegNum();
unsigned realRegByClass = getRealRegNum(fakeReg, MI);
DEBUG(std::cerr << MO << ": Reg[" << std::dec << fakeReg << "] => "
<< realRegByClass << " (LLC: "
<< TM.getRegInfo().getUnifiedRegName(fakeReg) << ")\n");
rv = realRegByClass;
} else if (MO.isImmediate()) {
rv = MO.getImmedValue();
DEBUG(std::cerr << "immed: " << rv << "\n");
} else if (MO.isGlobalAddress()) {
DEBUG(std::cerr << "GlobalAddress: not PC-relative\n");
rv = (int64_t)
(intptr_t)getGlobalAddress(cast<GlobalValue>(MO.getVRegValue()),
MI, MO.isPCRelative());
} else if (MO.isMachineBasicBlock()) {
// Duplicate code of the above case for VirtualRegister, BasicBlock...
// It should really hit this case, but Sparc backend uses VRegs instead
DEBUG(std::cerr << "Saving reference to MBB\n");
const BasicBlock *BB = MO.getMachineBasicBlock()->getBasicBlock();
unsigned* CurrPC = (unsigned*)(intptr_t)MCE.getCurrentPCValue();
BBRefs.push_back(std::make_pair(BB, std::make_pair(CurrPC, &MI)));
} else if (MO.isExternalSymbol()) {
// Sparc backend doesn't generate this (yet...)
std::cerr << "ERROR: External symbol unhandled: " << MO << "\n";
abort();
} else if (MO.isFrameIndex()) {
// Sparc backend doesn't generate this (yet...)
int FrameIndex = MO.getFrameIndex();
std::cerr << "ERROR: Frame index unhandled.\n";
abort();
} else if (MO.isConstantPoolIndex()) {
// Sparc backend doesn't generate this (yet...)
std::cerr << "ERROR: Constant Pool index unhandled.\n";
abort();
} else {
std::cerr << "ERROR: Unknown type of MachineOperand: " << MO << "\n";
abort();
}
// Finally, deal with the various bitfield-extracting functions that
// are used in SPARC assembly. (Some of these make no sense in combination
// with some of the above; we'll trust that the instruction selector
// will not produce nonsense, and not check for valid combinations here.)
if (MO.opLoBits32()) { // %lo(val) == %lo() in Sparc ABI doc
return rv & 0x03ff;
} else if (MO.opHiBits32()) { // %lm(val) == %hi() in Sparc ABI doc
return (rv >> 10) & 0x03fffff;
} else if (MO.opLoBits64()) { // %hm(val) == %ulo() in Sparc ABI doc
return (rv >> 32) & 0x03ff;
} else if (MO.opHiBits64()) { // %hh(val) == %uhi() in Sparc ABI doc
return rv >> 42;
} else { // (unadorned) val
return rv;
}
}
unsigned SparcV9CodeEmitter::getValueBit(int64_t Val, unsigned bit) {
Val >>= bit;
return (Val & 1);
}
bool SparcV9CodeEmitter::runOnMachineFunction(MachineFunction &MF) {
MCE.startFunction(MF);
DEBUG(std::cerr << "Starting function " << MF.getFunction()->getName()
<< ", address: " << "0x" << std::hex
<< (long)MCE.getCurrentPCValue() << "\n");
// The Sparc backend does not use MachineConstantPool;
// instead, it has its own constant pool implementation.
// We create a new MachineConstantPool here to be compatible with the emitter.
MachineConstantPool MCP;
const hash_set<const Constant*> &pool = MF.getInfo()->getConstantPoolValues();
for (hash_set<const Constant*>::const_iterator I = pool.begin(),
E = pool.end(); I != E; ++I)
{
Constant *C = (Constant*)*I;
unsigned idx = MCP.getConstantPoolIndex(C);
DEBUG(std::cerr << "Constant[" << idx << "] = 0x" << (intptr_t)C << "\n");
ConstantMap[C] = idx;
}
MCE.emitConstantPool(&MCP);
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
emitBasicBlock(*I);
MCE.finishFunction(MF);
DEBUG(std::cerr << "Finishing fn " << MF.getFunction()->getName() << "\n");
ConstantMap.clear();
// Resolve branches to BasicBlocks for the entire function
for (unsigned i = 0, e = BBRefs.size(); i != e; ++i) {
long Location = BBLocations[BBRefs[i].first];
unsigned *Ref = BBRefs[i].second.first;
MachineInstr *MI = BBRefs[i].second.second;
DEBUG(std::cerr << "Fixup @ " << std::hex << Ref << " to 0x" << Location
<< " in instr: " << std::dec << *MI);
for (unsigned ii = 0, ee = MI->getNumOperands(); ii != ee; ++ii) {
MachineOperand &op = MI->getOperand(ii);
if (op.isPCRelativeDisp()) {
// the instruction's branch target is made such that it branches to
// PC + (branchTarget * 4), so undo that arithmetic here:
// Location is the target of the branch
// Ref is the location of the instruction, and hence the PC
int64_t branchTarget = (Location - (long)Ref) >> 2;
// Save the flags.
bool loBits32=false, hiBits32=false, loBits64=false, hiBits64=false;
if (op.opLoBits32()) { loBits32=true; }
if (op.opHiBits32()) { hiBits32=true; }
if (op.opLoBits64()) { loBits64=true; }
if (op.opHiBits64()) { hiBits64=true; }
MI->SetMachineOperandConst(ii, MachineOperand::MO_SignExtendedImmed,
branchTarget);
if (loBits32) { MI->setOperandLo32(ii); }
else if (hiBits32) { MI->setOperandHi32(ii); }
else if (loBits64) { MI->setOperandLo64(ii); }
else if (hiBits64) { MI->setOperandHi64(ii); }
DEBUG(std::cerr << "Rewrote BB ref: ");
unsigned fixedInstr = SparcV9CodeEmitter::getBinaryCodeForInstr(*MI);
*Ref = fixedInstr;
break;
}
}
}
BBRefs.clear();
BBLocations.clear();
return false;
}
void SparcV9CodeEmitter::emitBasicBlock(MachineBasicBlock &MBB) {
currBB = MBB.getBasicBlock();
BBLocations[currBB] = MCE.getCurrentPCValue();
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end(); I != E; ++I){
unsigned binCode = getBinaryCodeForInstr(**I);
if (binCode == (1 << 30)) {
// this is an invalid call: the addr is out of bounds. that means a code
// sequence has already been emitted, and this is a no-op
DEBUG(std::cerr << "Call supressed: already emitted far call.\n");
} else {
emitWord(binCode);
}
}
}
void* SparcV9CodeEmitter::getGlobalAddress(GlobalValue *V, MachineInstr &MI,
bool isPCRelative)
{
if (isPCRelative) { // must be a call, this is a major hack!
// Try looking up the function to see if it is already compiled!
if (void *Addr = (void*)(intptr_t)MCE.getGlobalValueAddress(V)) {
intptr_t CurByte = MCE.getCurrentPCValue();
// The real target of the call is Addr = PC + (target * 4)
// CurByte is the PC, Addr we just received
return (void*) (((long)Addr - (long)CurByte) >> 2);
} else {
if (Function *F = dyn_cast<Function>(V)) {
// Function has not yet been code generated!
TheJITResolver->addFunctionReference(MCE.getCurrentPCValue(),
cast<Function>(V));
// Delayed resolution...
return
(void*)(intptr_t)TheJITResolver->getLazyResolver(cast<Function>(V));
} else if (Constant *C = ConstantPointerRef::get(V)) {
if (ConstantMap.find(C) != ConstantMap.end()) {
return (void*)
(intptr_t)MCE.getConstantPoolEntryAddress(ConstantMap[C]);
} else {
std::cerr << "Constant: 0x" << std::hex << &*C << std::dec
<< ", " << *V << " not found in ConstantMap!\n";
abort();
}
} else {
std::cerr << "Unhandled global: " << *V << "\n";
abort();
}
}
} else {
return (void*)(intptr_t)MCE.getGlobalValueAddress(V);
}
}
#include "SparcV9CodeEmitter.inc"
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