Fixed dllimported symbols support during JIT'ing. JIT on mingw32

platform should be more or less workable. At least, sim is running fine
under lli :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32711 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86Subtarget.cpp

@@ -32,6 +32,7 @@ AsmWriterFlavor("x86-asm-syntax", cl::init(X86Subtarget::unset),
 /// or index register of the address, not the GV offset field.
 bool X86Subtarget::GVRequiresExtraLoad(const GlobalValue* GV, bool isDirectCall) const
 {
+  if (GenerateExtraLoadsForGVs)
     if (isTargetDarwin()) {
       return (!isDirectCall &&
               (GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
@@ -206,6 +207,15 @@ static const char *GetCurrentX86CPU() {
   }
 }
 
+/// SetJITMode - This is called to inform the subtarget info that we are
+/// producing code for the JIT.
+void X86Subtarget::SetJITMode() {
+  // JIT mode doesn't want extra loads for dllimported symbols, it knows exactly
+  // where everything is.
+  if (isTargetCygwin())
+    GenerateExtraLoadsForGVs = false;
+}
+
 X86Subtarget::X86Subtarget(const Module &M, const std::string &FS, bool is64Bit)
   : AsmFlavor(AsmWriterFlavor)
   , X86SSELevel(NoMMXSSE)
@@ -214,6 +224,7 @@ X86Subtarget::X86Subtarget(const Module &M, const std::string &FS, bool is64Bit)
   // FIXME: this is a known good value for Yonah. How about others?
   , MinRepStrSizeThreshold(128)
   , Is64Bit(is64Bit)
+  , GenerateExtraLoadsForGVs(true)
   , TargetType(isELF) { // Default to ELF unless otherwise specified.
 
   // Determine default and user specified characteristics

lib/Target/X86/X86Subtarget.h

@@ -61,6 +61,9 @@ private:
   /// pointer size is 64 bit.
   bool Is64Bit;
 
+  /// GenerateExtraLoadsForGVs - True if we should generate extra loads for
+  /// indirect symbols (e.g. dllimported symbols on windows).
+  bool GenerateExtraLoadsForGVs;
 public:
   enum {
     isELF, isCygwin, isDarwin, isWindows
@@ -112,6 +115,10 @@ public:
   /// value of GV itself. This means that the GlobalAddress must be in the base
   /// or index register of the address, not the GV offset field.
   bool GVRequiresExtraLoad(const GlobalValue* GV, bool isDirectCall) const;
+
+  /// SetJITMode - This is called to inform the subtarget info that we are
+  /// producing code for the JIT.
+  void SetJITMode();
 };
 
 namespace X86 {

lib/Target/X86/X86TargetMachine.cpp

@@ -167,6 +167,9 @@ bool X86TargetMachine::addCodeEmitter(FunctionPassManager &PM, bool Fast,
   if (Subtarget.is64Bit())
     setCodeModel(CodeModel::Large);
 
+  // Inform the subtarget that we are in JIT mode.
+  Subtarget.SetJITMode(); 
+  
   PM.add(createX86CodeEmitterPass(*this, MCE));
   return false;
 }