1 //===-- SparcEmitter.cpp - Write machine code to executable memory --------===//
3 // This file defines a MachineCodeEmitter object that is used by Jello to write
4 // machine code to memory and remember where relocatable values lie.
6 //===----------------------------------------------------------------------===//
9 #include "llvm/CodeGen/MachineCodeEmitter.h"
10 #include "llvm/CodeGen/MachineFunction.h"
11 #include "llvm/CodeGen/MachineConstantPool.h"
12 #include "llvm/CodeGen/MachineInstr.h"
13 #include "llvm/Target/TargetData.h"
14 #include "llvm/Function.h"
15 #include "Support/Statistic.h"
17 #include "../../../lib/Target/Sparc/SparcV9CodeEmitter.h"
20 Statistic<> NumBytes("jello", "Number of bytes of machine code compiled");
22 class SparcEmitter : public MachineCodeEmitter {
25 unsigned char *CurBlock, *CurByte;
27 // When outputting a function stub in the context of some other function, we
28 // save CurBlock and CurByte here.
29 unsigned char *SavedCurBlock, *SavedCurByte;
31 std::vector<std::pair<BasicBlock*,
32 std::pair<unsigned*,MachineInstr*> > > BBRefs;
33 std::map<BasicBlock*, long> BBLocations;
34 std::vector<void*> ConstantPoolAddresses;
36 SparcEmitter(VM &vm) : TheVM(vm) {}
38 virtual void startFunction(MachineFunction &F);
39 virtual void finishFunction(MachineFunction &F);
40 virtual void emitConstantPool(MachineConstantPool *MCP);
41 virtual void startBasicBlock(MachineBasicBlock &BB);
42 virtual void startFunctionStub(const Function &F, unsigned StubSize);
43 virtual void* finishFunctionStub(const Function &F);
44 virtual void emitByte(unsigned char B);
45 virtual void emitPCRelativeDisp(Value *V);
46 virtual void emitGlobalAddress(GlobalValue *V, bool isPCRelative);
47 virtual void emitGlobalAddress(const std::string &Name, bool isPCRelative);
48 virtual void emitFunctionConstantValueAddress(unsigned ConstantNum,
51 virtual void saveBBreference(BasicBlock *BB, MachineInstr &MI);
55 void emitAddress(void *Addr, bool isPCRelative);
56 void* getMemory(unsigned NumPages);
60 MachineCodeEmitter *VM::createSparcEmitter(VM &V) {
61 return new SparcEmitter(V);
65 #define _POSIX_MAPPED_FILES
69 // FIXME: This should be rewritten to support a real memory manager for
70 // executable memory pages!
71 void* SparcEmitter::getMemory(unsigned NumPages) {
73 if (NumPages == 0) return 0;
74 static const long pageSize = sysconf (_SC_PAGESIZE);
75 pa = mmap(0, pageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
76 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
77 if (pa == MAP_FAILED) {
85 void SparcEmitter::startFunction(MachineFunction &F) {
86 std::cerr << "Starting function " << F.getFunction()->getName() << "\n";
87 CurBlock = (unsigned char *)getMemory(8);
88 CurByte = CurBlock; // Start writing at the beginning of the fn.
89 TheVM.addGlobalMapping(F.getFunction(), CurBlock);
92 void SparcEmitter::finishFunction(MachineFunction &F) {
93 std::cerr << "Finishing function " << F.getFunction()->getName() << "\n";
94 ConstantPoolAddresses.clear();
95 // Re-write branches to BasicBlocks for the entire function
96 for (unsigned i = 0, e = BBRefs.size(); i != e; ++i) {
97 long Location = BBLocations[BBRefs[i].first];
98 unsigned *Ref = BBRefs[i].second.first;
99 MachineInstr *MI = BBRefs[i].second.second;
100 std::cerr << "attempting to resolve BB: " << i << "\n";
101 for (unsigned ii = 0, ee = MI->getNumOperands(); ii != ee; ++ii) {
102 MachineOperand &op = MI->getOperand(ii);
103 if (op.isPCRelativeDisp()) {
104 // the instruction's branch target is made such that it branches to
105 // PC + (br target * 4), so undo that arithmetic here:
106 // Location is the target of the branch
107 // Ref is the location of the instruction, and hence the PC
108 unsigned branchTarget = (Location - (long)Ref) >> 2;
110 bool loBits32=false, hiBits32=false, loBits64=false, hiBits64=false;
111 if (op.opLoBits32()) { loBits32=true; }
112 if (op.opHiBits32()) { hiBits32=true; }
113 if (op.opLoBits64()) { loBits64=true; }
114 if (op.opHiBits64()) { hiBits64=true; }
115 MI->SetMachineOperandConst(ii, MachineOperand::MO_SignExtendedImmed,
117 if (loBits32) { MI->setOperandLo32(ii); }
118 else if (hiBits32) { MI->setOperandHi32(ii); }
119 else if (loBits64) { MI->setOperandLo64(ii); }
120 else if (hiBits64) { MI->setOperandHi64(ii); }
121 std::cerr << "Rewrote BB ref: ";
122 unsigned fixedInstr = SparcV9CodeEmitter::getBinaryCodeForInstr(*MI);
131 NumBytes += CurByte-CurBlock;
133 DEBUG(std::cerr << "Finished CodeGen of [0x" << std::hex
134 << (unsigned)(intptr_t)CurBlock
135 << std::dec << "] Function: " << F.getFunction()->getName()
136 << ": " << CurByte-CurBlock << " bytes of text\n");
139 void SparcEmitter::emitConstantPool(MachineConstantPool *MCP) {
140 const std::vector<Constant*> &Constants = MCP->getConstants();
141 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
142 // For now we just allocate some memory on the heap, this can be
143 // dramatically improved.
144 const Type *Ty = ((Value*)Constants[i])->getType();
145 void *Addr = malloc(TheVM.getTargetData().getTypeSize(Ty));
146 TheVM.InitializeMemory(Constants[i], Addr);
147 ConstantPoolAddresses.push_back(Addr);
152 void SparcEmitter::startBasicBlock(MachineBasicBlock &BB) {
153 BBLocations[BB.getBasicBlock()] = (long)(intptr_t)CurByte;
157 void SparcEmitter::startFunctionStub(const Function &F, unsigned StubSize) {
158 SavedCurBlock = CurBlock; SavedCurByte = CurByte;
159 // FIXME: this is a huge waste of memory.
160 CurBlock = (unsigned char *)getMemory((StubSize+4095)/4096);
161 CurByte = CurBlock; // Start writing at the beginning of the fn.
164 void *SparcEmitter::finishFunctionStub(const Function &F) {
165 NumBytes += CurByte-CurBlock;
166 DEBUG(std::cerr << "Finished CodeGen of [0x" << std::hex
167 << (unsigned)(intptr_t)CurBlock
168 << std::dec << "] Function stub for: " << F.getName()
169 << ": " << CurByte-CurBlock << " bytes of text\n");
170 std::swap(CurBlock, SavedCurBlock);
171 CurByte = SavedCurByte;
172 return SavedCurBlock;
175 void SparcEmitter::emitByte(unsigned char B) {
176 *CurByte++ = B; // Write the byte to memory
179 // BasicBlock -> pair<memloc, MachineInstr>
180 // when the BB is emitted, machineinstr is modified with then-currbyte,
181 // processed with MCE, and written out at memloc.
182 // Should be called by the emitter if its outputting a PCRelative disp
183 void SparcEmitter::saveBBreference(BasicBlock *BB, MachineInstr &MI) {
184 BBRefs.push_back(std::make_pair(BB, std::make_pair((unsigned*)CurByte, &MI)));
188 // emitPCRelativeDisp - For functions, just output a displacement that will
189 // cause a reference to the zero page, which will cause a seg-fault, causing
190 // things to get resolved on demand. Keep track of these markers.
192 // For basic block references, keep track of where the references are so they
193 // may be patched up when the basic block is defined.
195 // BasicBlock -> pair<memloc, MachineInstr>
196 // when the BB is emitted, machineinstr is modified with then-currbyte,
197 // processed with MCE, and written out at memloc.
199 void SparcEmitter::emitPCRelativeDisp(Value *V) {
201 BasicBlock *BB = cast<BasicBlock>(V); // Keep track of reference...
202 BBRefs.push_back(std::make_pair(BB, (unsigned*)CurByte));
207 // emitAddress - Emit an address in either direct or PCRelative form...
209 void SparcEmitter::emitAddress(void *Addr, bool isPCRelative) {
212 *(intptr_t*)CurByte = (intptr_t)Addr - (intptr_t)CurByte-4;
214 *(void**)CurByte = Addr;
220 void SparcEmitter::emitGlobalAddress(GlobalValue *V, bool isPCRelative) {
221 if (isPCRelative) { // must be a call, this is a major hack!
222 // Try looking up the function to see if it is already compiled!
223 if (void *Addr = TheVM.getPointerToGlobalIfAvailable(V)) {
224 emitAddress(Addr, isPCRelative);
225 } else { // Function has not yet been code generated!
226 TheVM.addFunctionRef(CurByte, cast<Function>(V));
228 // Delayed resolution...
229 emitAddress((void*)VM::CompilationCallback, isPCRelative);
232 emitAddress(TheVM.getPointerToGlobal(V), isPCRelative);
236 void SparcEmitter::emitGlobalAddress(const std::string &Name, bool isPCRelative)
239 emitAddress(TheVM.getPointerToNamedFunction(Name), isPCRelative);
243 void SparcEmitter::emitFunctionConstantValueAddress(unsigned ConstantNum,
245 assert(ConstantNum < ConstantPoolAddresses.size() &&
246 "Invalid ConstantPoolIndex!");
247 *(void**)CurByte = (char*)ConstantPoolAddresses[ConstantNum]+Offset;