[AMDGPU] Add GlobalOpt parameter to Always Inliner pass

If set to false it does not remove global aliases. With this parameter
set to false it should be safe to run the pass before link.

Differential Revision: https://reviews.llvm.org/D31489

llvm-svn: 299108

llvm/lib/Target/AMDGPU/AMDGPU.h

@@ -98,7 +98,7 @@ extern char &AMDGPUPromoteAllocaID;
 Pass *createAMDGPUStructurizeCFGPass();
 FunctionPass *createAMDGPUISelDag(TargetMachine &TM,
                                   CodeGenOpt::Level OptLevel);
-ModulePass *createAMDGPUAlwaysInlinePass();
+ModulePass *createAMDGPUAlwaysInlinePass(bool GlobalOpt = true);
 ModulePass *createAMDGPUOpenCLImageTypeLoweringPass();
 FunctionPass *createAMDGPUAnnotateUniformValues();
 

llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp

@@ -24,8 +24,10 @@ namespace {
 class AMDGPUAlwaysInline : public ModulePass {
   static char ID;
 
+  bool GlobalOpt;
+
 public:
-  AMDGPUAlwaysInline() : ModulePass(ID) { }
+  AMDGPUAlwaysInline(bool GlobalOpt) : ModulePass(ID), GlobalOpt(GlobalOpt) { }
   bool runOnModule(Module &M) override;
   StringRef getPassName() const override { return "AMDGPU Always Inline Pass"; }
 };
@@ -45,8 +47,10 @@ bool AMDGPUAlwaysInline::runOnModule(Module &M) {
     }
   }
 
-  for (GlobalAlias* A : AliasesToRemove) {
-    A->eraseFromParent();
+  if (GlobalOpt) {
+    for (GlobalAlias* A : AliasesToRemove) {
+      A->eraseFromParent();
+    }
   }
 
   for (Function &F : M) {
@@ -70,6 +74,6 @@ bool AMDGPUAlwaysInline::runOnModule(Module &M) {
   return false;
 }
 
-ModulePass *llvm::createAMDGPUAlwaysInlinePass() {
-  return new AMDGPUAlwaysInline();
+ModulePass *llvm::createAMDGPUAlwaysInlinePass(bool GlobalOpt) {
+  return new AMDGPUAlwaysInline(GlobalOpt);
 }

llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

@@ -315,7 +315,7 @@ void AMDGPUTargetMachine::adjustPassManager(PassManagerBuilder &Builder) {
         PM.add(createGlobalDCEPass());
       }
       if (EarlyInline)
-        PM.add(createAMDGPUAlwaysInlinePass());
+        PM.add(createAMDGPUAlwaysInlinePass(false));
   });
 
   Builder.addExtension(

llvm/test/CodeGen/AMDGPU/early-inline.ll

 ; RUN: opt -mtriple=amdgcn-- -O1 -S -inline-threshold=1 -amdgpu-early-inline-all %s | FileCheck %s
 
+; CHECK: @c_alias
+@c_alias = alias i32 (i32), i32 (i32)* @callee
+
 define i32 @callee(i32 %x) {
 entry:
   %mul1 = mul i32 %x, %x