Allow more than one stub to be being generated at the same time.

It's probably better in the long run to replace the
indirect-GlobalVariable system. That'll be done after a subsequent
patch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89708 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 46 insertions, 52 deletions

diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index aabab98dcc..f34ae00f8b 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -268,10 +268,6 @@ namespace {
   class JITEmitter : public JITCodeEmitter {
     JITMemoryManager *MemMgr;
 
-    // When outputting a function stub in the context of some other function, we
-    // save BufferBegin/BufferEnd/CurBufferPtr here.
-    uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
-
     // When reattempting to JIT a function after running out of space, we store
     // the estimated size of the function we're trying to JIT here, so we can
     // ask the memory manager for at least this much space.  When we
@@ -397,11 +393,11 @@ namespace {
     void initJumpTableInfo(MachineJumpTableInfo *MJTI);
     void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
 
-    virtual void startGVStub(const GlobalValue* GV, unsigned StubSize,
-                                   unsigned Alignment = 1);
-    virtual void startGVStub(const GlobalValue* GV, void *Buffer,
+    virtual void startGVStub(BufferState &BS, const GlobalValue* GV,
+                             unsigned StubSize, unsigned Alignment = 1);
+    virtual void startGVStub(BufferState &BS, void *Buffer,
                              unsigned StubSize);
-    virtual void* finishGVStub(const GlobalValue *GV);
+    virtual void* finishGVStub(BufferState &BS);
 
     /// allocateSpace - Reserves space in the current block if any, or
     /// allocate a new one of the given size.
@@ -1207,9 +1203,8 @@ bool JITEmitter::finishFunction(MachineFunction &F) {
 
   if (DwarfExceptionHandling || JITEmitDebugInfo) {
     uintptr_t ActualSize = 0;
-    SavedBufferBegin = BufferBegin;
-    SavedBufferEnd = BufferEnd;
-    SavedCurBufferPtr = CurBufferPtr;
+    BufferState BS;
+    SaveStateTo(BS);
 
     if (MemMgr->NeedsExactSize()) {
       ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
@@ -1225,9 +1220,7 @@ bool JITEmitter::finishFunction(MachineFunction &F) {
     MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
                               FrameRegister);
     uint8_t *EhEnd = CurBufferPtr;
-    BufferBegin = SavedBufferBegin;
-    BufferEnd = SavedBufferEnd;
-    CurBufferPtr = SavedCurBufferPtr;
+    RestoreStateFrom(BS);
 
     if (DwarfExceptionHandling) {
       TheJIT->RegisterTable(FrameRegister);
@@ -1433,32 +1426,26 @@ void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
   }
 }
 
-void JITEmitter::startGVStub(const GlobalValue* GV, unsigned StubSize,
-                             unsigned Alignment) {
-  SavedBufferBegin = BufferBegin;
-  SavedBufferEnd = BufferEnd;
-  SavedCurBufferPtr = CurBufferPtr;
+void JITEmitter::startGVStub(BufferState &BS, const GlobalValue* GV,
+                             unsigned StubSize, unsigned Alignment) {
+  SaveStateTo(BS);
 
   BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
   BufferEnd = BufferBegin+StubSize+1;
 }
 
-void JITEmitter::startGVStub(const GlobalValue* GV, void *Buffer,
-                             unsigned StubSize) {
-  SavedBufferBegin = BufferBegin;
-  SavedBufferEnd = BufferEnd;
-  SavedCurBufferPtr = CurBufferPtr;
+void JITEmitter::startGVStub(BufferState &BS, void *Buffer, unsigned StubSize) {
+  SaveStateTo(BS);
 
   BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
   BufferEnd = BufferBegin+StubSize+1;
 }
 
-void *JITEmitter::finishGVStub(const GlobalValue* GV) {
+void *JITEmitter::finishGVStub(BufferState &BS) {
   NumBytes += getCurrentPCOffset();
-  std::swap(SavedBufferBegin, BufferBegin);
-  BufferEnd = SavedBufferEnd;
-  CurBufferPtr = SavedCurBufferPtr;
-  return SavedBufferBegin;
+  void *Result = BufferBegin;
+  RestoreStateFrom(BS);
+  return Result;
 }
 
 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
diff --git a/lib/Target/ARM/ARMJITInfo.cpp b/lib/Target/ARM/ARMJITInfo.cpp
index bdddcd67fa..7031640471 100644
--- a/lib/Target/ARM/ARMJITInfo.cpp
+++ b/lib/Target/ARM/ARMJITInfo.cpp
@@ -139,7 +139,8 @@ ARMJITInfo::getLazyResolverFunction(JITCompilerFn F) {
 
 void *ARMJITInfo::emitGlobalValueIndirectSym(const GlobalValue *GV, void *Ptr,
                                              JITCodeEmitter &JCE) {
-  JCE.startGVStub(GV, 4, 4);
+  MachineCodeEmitter::BufferState BS;
+  JCE.startGVStub(BS, GV, 4, 4);
   intptr_t Addr = (intptr_t)JCE.getCurrentPCValue();
   if (!sys::Memory::setRangeWritable((void*)Addr, 4)) {
     llvm_unreachable("ERROR: Unable to mark indirect symbol writable");
@@ -148,13 +149,14 @@ void *ARMJITInfo::emitGlobalValueIndirectSym(const GlobalValue *GV, void *Ptr,
   if (!sys::Memory::setRangeExecutable((void*)Addr, 4)) {
     llvm_unreachable("ERROR: Unable to mark indirect symbol executable");
   }
-  void *PtrAddr = JCE.finishGVStub(GV);
+  void *PtrAddr = JCE.finishGVStub(BS);
   addIndirectSymAddr(Ptr, (intptr_t)PtrAddr);
   return PtrAddr;
 }
 
 void *ARMJITInfo::emitFunctionStub(const Function* F, void *Fn,
                                    JITCodeEmitter &JCE) {
+  MachineCodeEmitter::BufferState BS;
   // If this is just a call to an external function, emit a branch instead of a
   // call.  The code is the same except for one bit of the last instruction.
   if (Fn != (void*)(intptr_t)ARMCompilationCallback) {
@@ -172,7 +174,7 @@ void *ARMJITInfo::emitFunctionStub(const Function* F, void *Fn,
                 errs() << "JIT: Stub emitted at [" << LazyPtr
                        << "] for external function at '" << Fn << "'\n");
       }
-      JCE.startGVStub(F, 16, 4);
+      JCE.startGVStub(BS, F, 16, 4);
       intptr_t Addr = (intptr_t)JCE.getCurrentPCValue();
       if (!sys::Memory::setRangeWritable((void*)Addr, 16)) {
         llvm_unreachable("ERROR: Unable to mark stub writable");
@@ -187,7 +189,7 @@ void *ARMJITInfo::emitFunctionStub(const Function* F, void *Fn,
       }
     } else {
       // The stub is 8-byte size and 4-aligned.
-      JCE.startGVStub(F, 8, 4);
+      JCE.startGVStub(BS, F, 8, 4);
       intptr_t Addr = (intptr_t)JCE.getCurrentPCValue();
       if (!sys::Memory::setRangeWritable((void*)Addr, 8)) {
         llvm_unreachable("ERROR: Unable to mark stub writable");
@@ -207,7 +209,7 @@ void *ARMJITInfo::emitFunctionStub(const Function* F, void *Fn,
     //
     // Branch and link to the compilation callback.
     // The stub is 16-byte size and 4-byte aligned.
-    JCE.startGVStub(F, 16, 4);
+    JCE.startGVStub(BS, F, 16, 4);
     intptr_t Addr = (intptr_t)JCE.getCurrentPCValue();
     if (!sys::Memory::setRangeWritable((void*)Addr, 16)) {
       llvm_unreachable("ERROR: Unable to mark stub writable");
@@ -228,7 +230,7 @@ void *ARMJITInfo::emitFunctionStub(const Function* F, void *Fn,
     }
   }
 
-  return JCE.finishGVStub(F);
+  return JCE.finishGVStub(BS);
 }
 
 intptr_t ARMJITInfo::resolveRelocDestAddr(MachineRelocation *MR) const {
diff --git a/lib/Target/Alpha/AlphaJITInfo.cpp b/lib/Target/Alpha/AlphaJITInfo.cpp
index d32813552f..4e59833953 100644
--- a/lib/Target/Alpha/AlphaJITInfo.cpp
+++ b/lib/Target/Alpha/AlphaJITInfo.cpp
@@ -192,15 +192,16 @@ extern "C" {
 
 void *AlphaJITInfo::emitFunctionStub(const Function* F, void *Fn,
                                      JITCodeEmitter &JCE) {
+  MachineCodeEmitter::BufferState BS;
   //assert(Fn == AlphaCompilationCallback && "Where are you going?\n");
   //Do things in a stupid slow way!
-  JCE.startGVStub(F, 19*4);
+  JCE.startGVStub(BS, F, 19*4);
   void* Addr = (void*)(intptr_t)JCE.getCurrentPCValue();
   for (int x = 0; x < 19; ++ x)
     JCE.emitWordLE(0);
   EmitBranchToAt(Addr, Fn);
   DEBUG(errs() << "Emitting Stub to " << Fn << " at [" << Addr << "]\n");
-  return JCE.finishGVStub(F);
+  return JCE.finishGVStub(BS);
 }
 
 TargetJITInfo::LazyResolverFn
diff --git a/lib/Target/PowerPC/PPCJITInfo.cpp b/lib/Target/PowerPC/PPCJITInfo.cpp
index ef25d92f71..ddbb326570 100644
--- a/lib/Target/PowerPC/PPCJITInfo.cpp
+++ b/lib/Target/PowerPC/PPCJITInfo.cpp
@@ -330,11 +330,12 @@ extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
 
 void *PPCJITInfo::emitFunctionStub(const Function* F, void *Fn,
                                    JITCodeEmitter &JCE) {
+  MachineCodeEmitter::BufferState BS;
   // If this is just a call to an external function, emit a branch instead of a
   // call.  The code is the same except for one bit of the last instruction.
   if (Fn != (void*)(intptr_t)PPC32CompilationCallback && 
       Fn != (void*)(intptr_t)PPC64CompilationCallback) {
-    JCE.startGVStub(F, 7*4);
+    JCE.startGVStub(BS, F, 7*4);
     intptr_t Addr = (intptr_t)JCE.getCurrentPCValue();
     JCE.emitWordBE(0);
     JCE.emitWordBE(0);
@@ -345,10 +346,10 @@ void *PPCJITInfo::emitFunctionStub(const Function* F, void *Fn,
     JCE.emitWordBE(0);
     EmitBranchToAt(Addr, (intptr_t)Fn, false, is64Bit);
     sys::Memory::InvalidateInstructionCache((void*)Addr, 7*4);
-    return JCE.finishGVStub(F);
+    return JCE.finishGVStub(BS);
   }
 
-  JCE.startGVStub(F, 10*4);
+  JCE.startGVStub(BS, F, 10*4);
   intptr_t Addr = (intptr_t)JCE.getCurrentPCValue();
   if (is64Bit) {
     JCE.emitWordBE(0xf821ffb1);     // stdu r1,-80(r1)
@@ -373,7 +374,7 @@ void *PPCJITInfo::emitFunctionStub(const Function* F, void *Fn,
   JCE.emitWordBE(0);
   EmitBranchToAt(BranchAddr, (intptr_t)Fn, true, is64Bit);
   sys::Memory::InvalidateInstructionCache((void*)Addr, 10*4);
-  return JCE.finishGVStub(F);
+  return JCE.finishGVStub(BS);
 }
 
 
diff --git a/lib/Target/X86/X86JITInfo.cpp b/lib/Target/X86/X86JITInfo.cpp
index 0792bdd4dd..a14c155f17 100644
--- a/lib/Target/X86/X86JITInfo.cpp
+++ b/lib/Target/X86/X86JITInfo.cpp
@@ -426,19 +426,21 @@ X86JITInfo::X86JITInfo(X86TargetMachine &tm) : TM(tm) {
 
 void *X86JITInfo::emitGlobalValueIndirectSym(const GlobalValue* GV, void *ptr,
                                              JITCodeEmitter &JCE) {
+  MachineCodeEmitter::BufferState BS;
 #if defined (X86_64_JIT)
-  JCE.startGVStub(GV, 8, 8);
+  JCE.startGVStub(BS, GV, 8, 8);
   JCE.emitWordLE((unsigned)(intptr_t)ptr);
   JCE.emitWordLE((unsigned)(((intptr_t)ptr) >> 32));
 #else
-  JCE.startGVStub(GV, 4, 4);
+  JCE.startGVStub(BS, GV, 4, 4);
   JCE.emitWordLE((intptr_t)ptr);
 #endif
-  return JCE.finishGVStub(GV);
+  return JCE.finishGVStub(BS);
 }
 
 void *X86JITInfo::emitFunctionStub(const Function* F, void *Fn,
                                    JITCodeEmitter &JCE) {
+  MachineCodeEmitter::BufferState BS;
   // Note, we cast to intptr_t here to silence a -pedantic warning that 
   // complains about casting a function pointer to a normal pointer.
 #if defined (X86_32_JIT) && !defined (_MSC_VER)
@@ -449,7 +451,7 @@ void *X86JITInfo::emitFunctionStub(const Function* F, void *Fn,
 #endif
   if (NotCC) {
 #if defined (X86_64_JIT)
-    JCE.startGVStub(F, 13, 4);
+    JCE.startGVStub(BS, F, 13, 4);
     JCE.emitByte(0x49);          // REX prefix
     JCE.emitByte(0xB8+2);        // movabsq r10
     JCE.emitWordLE((unsigned)(intptr_t)Fn);
@@ -458,15 +460,15 @@ void *X86JITInfo::emitFunctionStub(const Function* F, void *Fn,
     JCE.emitByte(0xFF);          // jmpq *r10
     JCE.emitByte(2 | (4 << 3) | (3 << 6));
 #else
-    JCE.startGVStub(F, 5, 4);
+    JCE.startGVStub(BS, F, 5, 4);
     JCE.emitByte(0xE9);
     JCE.emitWordLE((intptr_t)Fn-JCE.getCurrentPCValue()-4);
 #endif
-    return JCE.finishGVStub(F);
+    return JCE.finishGVStub(BS);
   }
 
 #if defined (X86_64_JIT)
-  JCE.startGVStub(F, 14, 4);
+  JCE.startGVStub(BS, F, 14, 4);
   JCE.emitByte(0x49);          // REX prefix
   JCE.emitByte(0xB8+2);        // movabsq r10
   JCE.emitWordLE((unsigned)(intptr_t)Fn);
@@ -475,7 +477,7 @@ void *X86JITInfo::emitFunctionStub(const Function* F, void *Fn,
   JCE.emitByte(0xFF);          // callq *r10
   JCE.emitByte(2 | (2 << 3) | (3 << 6));
 #else
-  JCE.startGVStub(F, 6, 4);
+  JCE.startGVStub(BS, F, 6, 4);
   JCE.emitByte(0xE8);   // Call with 32 bit pc-rel destination...
 
   JCE.emitWordLE((intptr_t)Fn-JCE.getCurrentPCValue()-4);
@@ -485,14 +487,15 @@ void *X86JITInfo::emitFunctionStub(const Function* F, void *Fn,
   // initialize the buffer with garbage, which means it may follow a
   // noreturn function call, confusing X86CompilationCallback2.  PR 4929.
   JCE.emitByte(0xCE);   // Interrupt - Just a marker identifying the stub!
-  return JCE.finishGVStub(F);
+  return JCE.finishGVStub(BS);
 }
 
 void X86JITInfo::emitFunctionStubAtAddr(const Function* F, void *Fn, void *Stub,
                                         JITCodeEmitter &JCE) {
+  MachineCodeEmitter::BufferState BS;
   // Note, we cast to intptr_t here to silence a -pedantic warning that 
   // complains about casting a function pointer to a normal pointer.
-  JCE.startGVStub(F, Stub, 5);
+  JCE.startGVStub(BS, Stub, 5);
   JCE.emitByte(0xE9);
 #if defined (X86_64_JIT) && !defined (NDEBUG)
   // Yes, we need both of these casts, or some broken versions of GCC (4.2.4)
@@ -502,7 +505,7 @@ void X86JITInfo::emitFunctionStubAtAddr(const Function* F, void *Fn, void *Stub,
          && "PIC displacement does not fit in displacement field!");
 #endif
   JCE.emitWordLE((intptr_t)Fn-JCE.getCurrentPCValue()-4);
-  JCE.finishGVStub(F);
+  JCE.finishGVStub(BS);
 }
 
 /// getPICJumpTableEntry - Returns the value of the jumptable entry for the