3 files changed, 29 insertions, 16 deletions
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index dce3389b01..fd8ce78654 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -561,6 +561,9 @@ bool FastISel::SelectCall(const User *I) {
     return true;
   }
 
+  MachineModuleInfo &MMI = FuncInfo.MF->getMMI();
+  ComputeUsesVAFloatArgument(*Call, &MMI);
+
   const Function *F = Call->getCalledFunction();
   if (!F) return false;
 
diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 1b969a16af..fd8051e7ba 100644
--- a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #define DEBUG_TYPE "function-lowering-info"
+#include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/CodeGen/FunctionLoweringInfo.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/Function.h"
@@ -371,6 +372,30 @@ int FunctionLoweringInfo::getArgumentFrameIndex(const Argument *A) {
   return 0;
 }
 
+/// ComputeUsesVAFloatArgument - Determine if any floating-point values are
+/// being passed to this variadic function, and set the MachineModuleInfo's
+/// usesVAFloatArgument flag if so. This flag is used to emit an undefined
+/// reference to _fltused on Windows, which will link in MSVCRT's
+/// floating-point support.
+void llvm::ComputeUsesVAFloatArgument(const CallInst &I,
+                                      MachineModuleInfo *MMI)
+{
+  FunctionType *FT = cast<FunctionType>(
+    I.getCalledValue()->getType()->getContainedType(0));
+  if (FT->isVarArg() && !MMI->usesVAFloatArgument()) {
+    for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
+      Type* T = I.getArgOperand(i)->getType();
+      for (po_iterator<Type*> i = po_begin(T), e = po_end(T);
+           i != e; ++i) {
+        if (i->isFloatingPointTy()) {
+          MMI->setUsesVAFloatArgument(true);
+          return;
+        }
+      }
+    }
+  }
+}
+
 /// AddCatchInfo - Extract the personality and type infos from an eh.selector
 /// call, and add them to the specified machine basic block.
 void llvm::AddCatchInfo(const CallInst &I, MachineModuleInfo *MMI,
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 524a91a6da..e2375dac4b 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5454,23 +5454,8 @@ void SelectionDAGBuilder::visitCall(const CallInst &I) {
     return;
   }
 
-  // See if any floating point values are being passed to this function. This is
-  // used to emit an undefined reference to fltused on Windows.
-  FunctionType *FT =
-    cast<FunctionType>(I.getCalledValue()->getType()->getContainedType(0));
   MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
-  if (FT->isVarArg() &&
-      !MMI.callsExternalVAFunctionWithFloatingPointArguments()) {
-    for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
-      Type* T = I.getArgOperand(i)->getType();
-      for (po_iterator<Type*> i = po_begin(T), e = po_end(T);
-           i != e; ++i) {
-        if (!i->isFloatingPointTy()) continue;
-        MMI.setCallsExternalVAFunctionWithFloatingPointArguments(true);
-        break;
-      }
-    }
-  }
+  ComputeUsesVAFloatArgument(I, &MMI);
 
   const char *RenameFn = 0;
   if (Function *F = I.getCalledFunction()) {