From db5f24ce77875f92e8fe71efbbc9a53e990a84a4 Mon Sep 17 00:00:00 2001
From: Jeffrey Yasskin <jyasskin@google.com>
Date: Sat, 7 Nov 2009 08:51:52 +0000
Subject: Make the need-stub variables accurate and consistent.  In the case of
 MachineRelocations, "stub" always refers to a far-call stub or a
 load-a-faraway-global stub, so this patch adds "Far" to the term. (Other
 stubs are used for lazy compilation and dlsym address replacement.) The
 variable was also inconsistent between the positive and negative sense, and
 the positive sense ("NeedStub") was more demanding than is accurate (since a
 nearby-enough function can be called directly even if the platform often
 requires a stub). Since the negative sense causes double-negatives, I
 switched to "MayNeedFarStub" globally.

llvm-svn: 86363
---
 llvm/lib/ExecutionEngine/JIT/JITEmitter.cpp | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

(limited to 'llvm/lib/ExecutionEngine')

diff --git a/llvm/lib/ExecutionEngine/JIT/JITEmitter.cpp b/llvm/lib/ExecutionEngine/JIT/JITEmitter.cpp
index bc959d8b2be..8c831a59981 100644
--- a/llvm/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/llvm/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -491,9 +491,9 @@ namespace {
     JITMemoryManager *getMemMgr() const { return MemMgr; }
 
   private:
-    void *getPointerToGlobal(GlobalValue *GV, void *Reference, bool NoNeedStub);
-    void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference,
-                                    bool NoNeedStub);
+    void *getPointerToGlobal(GlobalValue *GV, void *Reference,
+                             bool MayNeedFarStub);
+    void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
     unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
     unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
     unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
@@ -737,7 +737,7 @@ void *JITResolver::JITCompilerFn(void *Stub) {
 // JITEmitter code.
 //
 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
-                                     bool DoesntNeedStub) {
+                                     bool MayNeedFarStub) {
   if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
     return TheJIT->getOrEmitGlobalVariable(GV);
 
@@ -747,7 +747,7 @@ void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
   // If we have already compiled the function, return a pointer to its body.
   Function *F = cast<Function>(V);
   void *ResultPtr;
-  if (!DoesntNeedStub) {
+  if (MayNeedFarStub) {
     // Return the function stub if it's already created.
     ResultPtr = Resolver.getFunctionStubIfAvailable(F);
     if (ResultPtr)
@@ -761,14 +761,14 @@ void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
   // 'compile' it, which really just adds it to the map.  In dlsym mode, 
   // external functions are forced through a stub, regardless of reloc type.
   if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode() &&
-      DoesntNeedStub && !TheJIT->areDlsymStubsEnabled())
+      !MayNeedFarStub && !TheJIT->areDlsymStubsEnabled())
     return TheJIT->getPointerToFunction(F);
 
   // Okay, the function has not been compiled yet, if the target callback
   // mechanism is capable of rewriting the instruction directly, prefer to do
   // that instead of emitting a stub.  This uses the lazy resolver, so is not
   // legal if lazy compilation is disabled.
-  if (DoesntNeedStub && TheJIT->isCompilingLazily())
+  if (!MayNeedFarStub && TheJIT->isCompilingLazily())
     return Resolver.AddCallbackAtLocation(F, Reference);
 
   // Otherwise, we have to emit a stub.
@@ -784,11 +784,10 @@ void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
   return StubAddr;
 }
 
-void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference,
-                                            bool NoNeedStub) {
+void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
   // Make sure GV is emitted first, and create a stub containing the fully
   // resolved address.
-  void *GVAddress = getPointerToGlobal(V, Reference, true);
+  void *GVAddress = getPointerToGlobal(V, Reference, false);
   void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
   
   // Add the stub to the current function's list of referenced stubs, so we can
@@ -1112,7 +1111,7 @@ bool JITEmitter::finishFunction(MachineFunction &F) {
                        << ResultPtr << "]\n"); 
 
           // If the target REALLY wants a stub for this function, emit it now.
-          if (!MR.doesntNeedStub()) {
+          if (MR.mayNeedFarStub()) {
             if (!TheJIT->areDlsymStubsEnabled()) {
               ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
             } else {
@@ -1127,11 +1126,10 @@ bool JITEmitter::finishFunction(MachineFunction &F) {
         } else if (MR.isGlobalValue()) {
           ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
                                          BufferBegin+MR.getMachineCodeOffset(),
-                                         MR.doesntNeedStub());
+                                         MR.mayNeedFarStub());
         } else if (MR.isIndirectSymbol()) {
-          ResultPtr = getPointerToGVIndirectSym(MR.getGlobalValue(),
-                                          BufferBegin+MR.getMachineCodeOffset(),
-                                          MR.doesntNeedStub());
+          ResultPtr = getPointerToGVIndirectSym(
+              MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
         } else if (MR.isBasicBlock()) {
           ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
         } else if (MR.isConstantPoolIndex()) {
-- 
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