Clarify that llvm.used can contain aliases.

Also add a check for llvm.used in the verifier and simplify clients now that
they can assume they have a ConstantArray.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180019 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 5 deletions

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 2d13db2c9c..9187c6c2be 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1213,7 +1213,7 @@ void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
   if (GV->getName() == "llvm.used") {
     if (MAI->hasNoDeadStrip())    // No need to emit this at all.
-      EmitLLVMUsedList(GV->getInitializer());
+      EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
     return true;
   }
 
@@ -1256,11 +1256,8 @@ bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
 /// global in the specified llvm.used list for which emitUsedDirectiveFor
 /// is true, as being used with this directive.
-void AsmPrinter::EmitLLVMUsedList(const Constant *List) {
+void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
   // Should be an array of 'i8*'.
-  const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
-  if (InitList == 0) return;
-
   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
     const GlobalValue *GV =
       dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());