Use shouldAssumeDSOLocal in isOffsetFoldingLegal.

This makes it slightly more powerful for dynamic-no-pic.

llvm-svn: 273704

2 files changed, 24 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 9d6c855bb82..dc7bb7ca817 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -311,17 +311,22 @@ TargetLowering::getPICJumpTableRelocBaseExpr(const MachineFunction *MF,
 
 bool
 TargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
-  // Assume that everything is safe in static mode.
-  if (getTargetMachine().getRelocationModel() == Reloc::Static)
-    return true;
+  const TargetMachine &TM = getTargetMachine();
+  Reloc::Model RM = TM.getRelocationModel();
+  const GlobalValue *GV = GA->getGlobal();
+  const Triple &TargetTriple = TM.getTargetTriple();
+
+  // If the address is not even local to this DSO we will have to load it from
+  // a got and then add the offset.
+  if (!shouldAssumeDSOLocal(RM, TargetTriple, *GV->getParent(), GV))
+    return false;
 
-  // In dynamic-no-pic mode, assume that known defined values are safe.
-  if (getTargetMachine().getRelocationModel() == Reloc::DynamicNoPIC &&
-      GA && GA->getGlobal()->isStrongDefinitionForLinker())
-    return true;
+  // If the code is position independent we will have to add a base register.
+  if (RM == Reloc::PIC_)
+    return false;
 
-  // Otherwise assume nothing is safe.
-  return false;
+  // Otherwise we can do it.
+  return true;
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/llvm/test/CodeGen/X86/ga-offset2.ll b/llvm/test/CodeGen/X86/ga-offset2.ll
new file mode 100644
index 00000000000..bc4a3493ff6
--- /dev/null
+++ b/llvm/test/CodeGen/X86/ga-offset2.ll
@@ -0,0 +1,10 @@
+; RUN: llc < %s -mtriple=i686-apple-darwin -relocation-model=dynamic-no-pic | FileCheck %s
+
+@var = external hidden global i32
+@p = external hidden global i32*
+
+define void @f() {
+; CHECK:  movl    $_var+40, _p
+  store i32* getelementptr (i32, i32* @var, i64 10), i32** @p
+  ret void
+}