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llvm-6502/lib/Target/SparcV9/SparcV9CodeEmitter.cpp
Chris Lattner 83d72bcd11 Instead of silently breaking, print notification of why this doesn't work. 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16870 91177308-0d34-0410-b5e6-96231b3b80d8
2004-10-09 21:13:51 +00:00

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//===-- SparcV9CodeEmitter.cpp --------------------------------------------===//
//
// 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.
//
//===----------------------------------------------------------------------===//
//
// SPARC-specific backend for emitting machine code to memory.
//
// This module also contains the code for lazily resolving the targets
// of call instructions, including the callback used to redirect calls
// to functions for which the code has not yet been generated into the
// JIT compiler.
//
// This file #includes SparcV9CodeEmitter.inc, which contains the code
// for getBinaryCodeForInstr(), a method that converts a MachineInstr
// into the corresponding binary machine code word.
//
//===----------------------------------------------------------------------===//
#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/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/hash_set"
#include "llvm/ADT/Statistic.h"
#include "SparcV9Internals.h"
#include "SparcV9TargetMachine.h"
#include "SparcV9RegInfo.h"
#include "SparcV9CodeEmitter.h"
#include "MachineFunctionInfo.h"
#include "llvm/Config/alloca.h"
namespace llvm {
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 SparcV9TargetMachine::addPassesToEmitMachineCode(FunctionPassManager &PM,
MachineCodeEmitter &MCE) {
PM.add(new SparcV9CodeEmitter(*this, MCE));
PM.add(createSparcV9MachineCodeDestructionPass());
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 void insertFarJumpAtAddr(int64_t Value, uint64_t Addr);
void insertJumpAtAddr(int64_t Value, uint64_t &Addr);
private:
uint64_t emitStubForFunction(Function *F);
static void SaveRegisters(uint64_t DoubleFP[], uint64_t CC[],
uint64_t Globals[]);
static void RestoreRegisters(uint64_t DoubleFP[], uint64_t CC[],
uint64_t Globals[]);
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;
uint64_t Stub = emitStubForFunction(F);
LazyResolverMap.insert(I, std::make_pair(F, Stub));
return Stub;
}
void JITResolver::insertJumpAtAddr(int64_t JumpTarget, uint64_t &Addr) {
DEBUG(std::cerr << "Emitting a jump to 0x" << std::hex << JumpTarget << "\n");
// If the target function is close enough to fit into the 19bit disp of
// BA, we should use this version, as it's much cheaper to generate.
int64_t BranchTarget = (JumpTarget-Addr) >> 2;
if (BranchTarget >= (1 << 19) || BranchTarget <= -(1 << 19)) {
TheJITResolver->insertFarJumpAtAddr(JumpTarget, Addr);
} else {
// ba <target>
MachineInstr *I = BuildMI(V9::BA, 1).addSImm(BranchTarget);
*((unsigned*)(intptr_t)Addr) = getBinaryCodeForInstr(*I);
Addr += 4;
delete I;
// nop
I = BuildMI(V9::NOP, 0);
*((unsigned*)(intptr_t)Addr) = getBinaryCodeForInstr(*I);
delete I;
}
}
void JITResolver::insertFarJumpAtAddr(int64_t Target, uint64_t Addr) {
static const unsigned
o6 = SparcV9IntRegClass::o6, g0 = SparcV9IntRegClass::g0,
g1 = SparcV9IntRegClass::g1, g5 = SparcV9IntRegClass::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;
}
}
void JITResolver::SaveRegisters(uint64_t DoubleFP[], uint64_t CC[],
uint64_t Globals[]) {
#if defined(__sparcv9)
__asm__ __volatile__ (// Save condition-code registers
"stx %%fsr, %0;\n\t"
"rd %%fprs, %1;\n\t"
"rd %%ccr, %2;\n\t"
: "=m"(CC[0]), "=r"(CC[1]), "=r"(CC[2]));
__asm__ __volatile__ (// Save globals g1 and g5
"stx %%g1, %0;\n\t"
"stx %%g5, %0;\n\t"
: "=m"(Globals[0]), "=m"(Globals[1]));
// 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]));
#else
std::cerr << "ERROR: RUNNING CODE THAT ONLY WORKS ON A SPARCV9 HOST!\n";
abort();
#endif
}
void JITResolver::RestoreRegisters(uint64_t DoubleFP[], uint64_t CC[],
uint64_t Globals[])
{
#if defined(__sparcv9)
__asm__ __volatile__ (// Restore condition-code registers
"ldx %0, %%fsr;\n\t"
"wr %1, 0, %%fprs;\n\t"
"wr %2, 0, %%ccr;\n\t"
:: "m"(CC[0]), "r"(CC[1]), "r"(CC[2]));
__asm__ __volatile__ (// Restore globals g1 and g5
"ldx %0, %%g1;\n\t"
"ldx %0, %%g5;\n\t"
:: "m"(Globals[0]), "m"(Globals[1]));
// 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]));
#else
std::cerr << "ERROR: RUNNING CODE THAT ONLY WORKS ON A SPARCV9 HOST!\n";
abort();
#endif
}
void JITResolver::CompilationCallback() {
// Local space to save the registers
uint64_t DoubleFP[32];
uint64_t CC[3];
uint64_t Globals[2];
SaveRegisters(DoubleFP, CC, Globals);
++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(__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");
#else
std::cerr << "ERROR: RUNNING CODE THAT ONLY WORKS ON A SPARCV9 HOST!\n";
abort();
#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 = SparcV9IntRegClass::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();
}
// Overwrite it
TheJITResolver->insertJumpAtAddr(Target, CodeBegin);
// Flush the I-Cache: FLUSH clears out a doubleword at a given address
// Self-modifying code MUST clear out the I-Cache to be portable
#if defined(__sparcv9)
for (int i = -Offset, e = 32-((int64_t)Offset); i < e; i += 8)
__asm__ __volatile__ ("flush %%i7 + %0" : : "r" (i));
#endif
// Change the return address to re-execute the restore, then the jump.
DEBUG(std::cerr << "Callback returning to: 0x"
<< std::hex << (CameFrom-Offset-12) << "\n");
#if defined(__sparcv9)
__asm__ __volatile__ ("sub %%i7, %0, %%i7" : : "r" (Offset+12));
#endif
RestoreRegisters(DoubleFP, CC, Globals);
}
/// 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 = SparcV9IntRegClass::o6, g0 = SparcV9IntRegClass::g0;
// restore %g0, 0, %g0
MachineInstr *R = BuildMI(V9::RESTOREi, 3).addMReg(g0).addSImm(0)
.addMReg(g0, MachineOperand::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) {
MCE.emitWord(Val);
}
unsigned
SparcV9CodeEmitter::getRealRegNum(unsigned fakeReg,
MachineInstr &MI) {
const SparcV9RegInfo &RI = *TM.getRegInfo();
unsigned regClass, regType = RI.getRegType(fakeReg);
// At least map fakeReg into its class
fakeReg = RI.getClassRegNum(fakeReg, regClass);
switch (regClass) {
case SparcV9RegInfo::IntRegClassID: {
// SparcV9 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 SparcV9RegInfo::FloatRegClassID: {
DEBUG(std::cerr << "FP reg: " << fakeReg << "\n");
if (regType == SparcV9RegInfo::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 == SparcV9RegInfo::FPDoubleRegType) {
// FIXME: This assumes that we only have 5-bit register fields!
// From SparcV9 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 SparcV9RegInfo::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 SparcV9RegInfo::FloatCCRegClassID: {
/* These are laid out %fcc0 - %fcc3 => 0 - 3, so are correct */
DEBUG(std::cerr << "FP CC reg: " << fakeReg << "\n");
return fakeReg;
}
case SparcV9RegInfo::SpecialRegClassID: {
// Currently only "special" reg is %fsr, which is encoded as 1 in
// instructions and 0 in SparcV9SpecialRegClass.
static const unsigned SpecialReg[] = { 1 };
assert(fakeReg < sizeof(SpecialReg)/sizeof(SpecialReg[0])
&& "Special register out of bounds for SpecialReg map");
DEBUG(std::cerr << "Special reg: " << SpecialReg[fakeReg] << "\n");
return SpecialReg[fakeReg];
}
default:
assert(0 && "Invalid unified register number in getRealRegNum");
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 = SparcV9IntRegClass::o6,
o7 = SparcV9IntRegClass::o7, g0 = SparcV9IntRegClass::g0,
g1 = SparcV9IntRegClass::g1, g5 = SparcV9IntRegClass::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];
}
}
void SparcV9JITInfo::replaceMachineCodeForFunction (void *Old, void *New) {
assert (TheJITResolver &&
"Can only call replaceMachineCodeForFunction from within JIT");
uint64_t Target = (uint64_t)(intptr_t)New;
uint64_t CodeBegin = (uint64_t)(intptr_t)Old;
TheJITResolver->insertJumpAtAddr(Target, CodeBegin);
}
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.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 ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
// The real target of the branch is CI = PC + (rv * 4)
// So undo that: give the instruction (CI - PC) / 4
rv = (CI->getRawValue() - MCE.getCurrentPCValue()) / 4;
} 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: ");
// NOTE: This results in stubs being generated even for
// external, native functions, which is not optimal. See PR103.
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);
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");
// address 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.isRegister() || MO.getType() == MachineOperand::MO_CCRegister)
{
// This is necessary because the SparcV9 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.getReg();
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 SparcV9 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()) {
// SparcV9 backend doesn't generate this (yet...)
std::cerr << "ERROR: External symbol unhandled: " << MO << "\n";
abort();
} else if (MO.isFrameIndex()) {
// SparcV9 backend doesn't generate this (yet...)
int FrameIndex = MO.getFrameIndex();
std::cerr << "ERROR: Frame index unhandled.\n";
abort();
} else if (MO.isConstantPoolIndex()) {
unsigned Index = MO.getConstantPoolIndex();
rv = MCE.getConstantPoolEntryAddress(Index);
} 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.isLoBits32()) { // %lo(val) == %lo() in SparcV9 ABI doc
return rv & 0x03ff;
} else if (MO.isHiBits32()) { // %lm(val) == %hi() in SparcV9 ABI doc
return (rv >> 10) & 0x03fffff;
} else if (MO.isLoBits64()) { // %hm(val) == %ulo() in SparcV9 ABI doc
return (rv >> 32) & 0x03ff;
} else if (MO.isHiBits64()) { // %hh(val) == %uhi() in SparcV9 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");
MCE.emitConstantPool(MF.getConstantPool());
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");
// 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.isLoBits32()) { loBits32=true; }
if (op.isHiBits32()) { hiBits32=true; }
if (op.isLoBits64()) { loBits64=true; }
if (op.isHiBits64()) { hiBits64=true; }
MI->SetMachineOperandConst(ii, MachineOperand::MO_SignExtendedImmed,
branchTarget);
if (loBits32) { MI->getOperand(ii).markLo32(); }
else if (hiBits32) { MI->getOperand(ii).markHi32(); }
else if (loBits64) { MI->getOperand(ii).markLo64(); }
else if (hiBits64) { MI->getOperand(ii).markHi64(); }
DEBUG(std::cerr << "Rewrote BB ref: ");
unsigned fixedInstr = SparcV9CodeEmitter::getBinaryCodeForInstr(*MI);
MCE.emitWordAt (fixedInstr, Ref);
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 suppressed: 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 {
std::cerr << "Unhandled global: " << *V << "\n";
abort();
}
}
} else {
return (void*)(intptr_t)MCE.getGlobalValueAddress(V);
}
}
#include "SparcV9CodeEmitter.inc"
} // End llvm namespace
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