Adding dllimport, dllexport and external weak linkage types.

[oota-llvm.git] / lib / Target / X86 / X86ISelLowering.cpp

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index dfd7aa590445c02a8b98f713125309166c0fd12f..166345c2b210fcfea181df5385a108570f1c03cf 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1964,6 +1964,15 @@ static bool DarwinGVRequiresExtraLoad(GlobalValue *GV) {
           (GV->isExternal() && !GV->hasNotBeenReadFromBytecode()));
 }
 
+/// WinndowsGVRequiresExtraLoad - true if accessing the GV requires an extra
+/// load. For Windows, dllimported variables (not functions!) are indirect,
+/// loading the value at address GV rather then the 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.
+static bool WindowsGVRequiresExtraLoad(GlobalValue *GV) {
+  return (isa<GlobalVariable>((Value*)GV) && GV->hasDLLImportLinkage());  
+}
+
 /// isUndefOrInRange - Op is either an undef node or a ConstantSDNode.  Return
 /// true if Op is undef or if its value falls within the specified range (L, H].
 static bool isUndefOrInRange(SDOperand Op, unsigned Low, unsigned Hi) {
@@ -3376,7 +3385,14 @@ X86TargetLowering::LowerGlobalAddress(SDOperand Op, SelectionDAG &DAG) {
         DarwinGVRequiresExtraLoad(GV))
       Result = DAG.getLoad(getPointerTy(), DAG.getEntryNode(),
                            Result, DAG.getSrcValue(NULL));
+  } else if (Subtarget->isTargetCygwin() || Subtarget->isTargetWindows()) {
+    // FIXME: What's about PIC?
+    if (WindowsGVRequiresExtraLoad(GV)) {
+      Result = DAG.getLoad(getPointerTy(), DAG.getEntryNode(),
+                           Result, DAG.getSrcValue(NULL));      
+    }    
   }
+  
 
   return Result;
 }