From eba808957e15290e4ade5d3a80c31c0e36bdd7bd Mon Sep 17 00:00:00 2001
From: Nikolay Haustov <Nikolay.Haustov@amd.com>
Date: Wed, 31 Aug 2016 11:18:33 +0000
Subject: [PATCH] AMDGPU/SI: Handle aliases in AMDGPUAlwaysInlinePass

Summary:
Simply replace usage of aliases to functions with aliasee.
This came up when bitcode linking to builtin library and
calls to aliases not being resolved.

Also made minor improvements to existing test.

Reviewers: tstellarAMD, alex-t, vpykhtin

Subscribers: arsenm, wdng, rampitec

Differential Revision: https://reviews.llvm.org/D24023

llvm-svn: 280221
---
 .../Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp  | 12 +++++++++
 llvm/test/CodeGen/AMDGPU/inline-calls.ll      | 25 +++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp
index 63f5fb3cdf00..886b1b0f2b2a 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp
@@ -35,8 +35,20 @@ public:
 char AMDGPUAlwaysInline::ID = 0;
 
 bool AMDGPUAlwaysInline::runOnModule(Module &M) {
+  std::vector<GlobalAlias*> AliasesToRemove;
   std::vector<Function *> FuncsToClone;
 
+  for (GlobalAlias &A : M.aliases()) {
+    if (Function* F = dyn_cast<Function>(A.getAliasee())) {
+      A.replaceAllUsesWith(F);
+      AliasesToRemove.push_back(&A);
+    }
+  }
+
+  for (GlobalAlias* A : AliasesToRemove) {
+    A->eraseFromParent();
+  }
+
   for (Function &F : M) {
     if (!F.hasLocalLinkage() && !F.isDeclaration() && !F.use_empty() &&
         !F.hasFnAttribute(Attribute::NoInline))
diff --git a/llvm/test/CodeGen/AMDGPU/inline-calls.ll b/llvm/test/CodeGen/AMDGPU/inline-calls.ll
index 33a4c832e75e..4541a902c1b8 100644
--- a/llvm/test/CodeGen/AMDGPU/inline-calls.ll
+++ b/llvm/test/CodeGen/AMDGPU/inline-calls.ll
@@ -10,6 +10,7 @@ entry:
 }
 
 ; CHECK: {{^}}kernel:
+; CHECK-NOT: call
 define void @kernel(i32 addrspace(1)* %out) {
 entry:
   %tmp0 = call i32 @func(i32 1)
@@ -18,8 +19,32 @@ entry:
 }
 
 ; CHECK: {{^}}kernel2:
+; CHECK-NOT: call
 define void @kernel2(i32 addrspace(1)* %out) {
 entry:
   call void @kernel(i32 addrspace(1)* %out)
   ret void
 }
+
+; CHECK-NOT: func_alias
+@func_alias = alias i32 (i32), i32 (i32)* @func
+
+; CHECK: {{^}}kernel3:
+; CHECK-NOT: call
+define void @kernel3(i32 addrspace(1)* %out) {
+entry:
+  %tmp0 = call i32 @func_alias(i32 1)
+  store i32 %tmp0, i32 addrspace(1)* %out
+  ret void
+}
+
+; CHECK-NOT: kernel_alias
+@kernel_alias = alias void (i32 addrspace(1)*), void (i32 addrspace(1)*)* @kernel
+
+; CHECK: {{^}}kernel4:
+; CHECK-NOT: call
+define void @kernel4(i32 addrspace(1)* %out) {
+entry:
+  call void @kernel_alias(i32 addrspace(1)* %out)
+  ret void
+}