Revert "AMDGPU: Force inlining if LDS global address is used"

This reverts commit r336587, it was causing test failures on the
sanitizer bots.

llvm-svn: 336623

1 files changed, 21 insertions, 87 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp
index d4bbb2c1eb8..c27425443ab 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAlwaysInlinePass.cpp
@@ -14,9 +14,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "AMDGPU.h"
-#include "AMDGPUTargetMachine.h"
-#include "Utils/AMDGPUBaseInfo.h"
-#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Transforms/Utils/Cloning.h"
 
@@ -33,18 +30,13 @@ static cl::opt<bool> StressCalls(
 class AMDGPUAlwaysInline : public ModulePass {
   bool GlobalOpt;
 
-  void recursivelyVisitUsers(GlobalValue &GV,
-                             SmallPtrSetImpl<Function *> &FuncsToAlwaysInline);
 public:
   static char ID;
 
   AMDGPUAlwaysInline(bool GlobalOpt = false) :
     ModulePass(ID), GlobalOpt(GlobalOpt) { }
   bool runOnModule(Module &M) override;
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.setPreservesAll();
- }
+  StringRef getPassName() const override { return "AMDGPU Always Inline Pass"; }
 };
 
 } // End anonymous namespace
@@ -54,53 +46,15 @@ INITIALIZE_PASS(AMDGPUAlwaysInline, "amdgpu-always-inline",
 
 char AMDGPUAlwaysInline::ID = 0;
 
-void AMDGPUAlwaysInline::recursivelyVisitUsers(
-  GlobalValue &GV,
-  SmallPtrSetImpl<Function *> &FuncsToAlwaysInline) {
-  SmallVector<User *, 16> Stack;
-
-  SmallPtrSet<const Value *, 8> Visited;
-
-  for (User *U : GV.users())
-    Stack.push_back(U);
-
-  while (!Stack.empty()) {
-    User *U = Stack.pop_back_val();
-    if (!Visited.insert(U).second)
-      continue;
-
-    if (Instruction *I = dyn_cast<Instruction>(U)) {
-      Function *F = I->getParent()->getParent();
-      if (!AMDGPU::isEntryFunctionCC(F->getCallingConv())) {
-        FuncsToAlwaysInline.insert(F);
-        Stack.push_back(F);
-      }
-
-      // No need to look at further users, but we do need to inline any callers.
-      continue;
-    }
-
-    for (User *UU : U->users())
-      Stack.push_back(UU);
-  }
-}
-
 bool AMDGPUAlwaysInline::runOnModule(Module &M) {
-  AMDGPUAS AMDGPUAS = AMDGPU::getAMDGPUAS(M);
-
   std::vector<GlobalAlias*> AliasesToRemove;
-
-  SmallPtrSet<Function *, 8> FuncsToAlwaysInline;
-  SmallPtrSet<Function *, 8> FuncsToNoInline;
+  std::vector<Function *> FuncsToClone;
 
   for (GlobalAlias &A : M.aliases()) {
     if (Function* F = dyn_cast<Function>(A.getAliasee())) {
       A.replaceAllUsesWith(F);
       AliasesToRemove.push_back(&A);
     }
-
-    // FIXME: If the aliasee isn't a function, it's some kind of constant expr
-    // cast that won't be inlined through.
   }
 
   if (GlobalOpt) {
@@ -109,51 +63,31 @@ bool AMDGPUAlwaysInline::runOnModule(Module &M) {
     }
   }
 
-  // Always force inlining of any function that uses an LDS global address. This
-  // is something of a workaround because we don't have a way of supporting LDS
-  // objects defined in functions. LDS is always allocated by a kernel, and it
-  // is difficult to manage LDS usage if a function may be used by multiple
-  // kernels.
-  //
-  // OpenCL doesn't allow declaring LDS in non-kernels, so in practice this
-  // should only appear when IPO passes manages to move LDs defined in a kernel
-  // into a single user function.
-
-  for (GlobalVariable &GV : M.globals()) {
-    // TODO: Region address
-    unsigned AS = GV.getType()->getAddressSpace();
-    if (AS != AMDGPUAS::LOCAL_ADDRESS && AS != AMDGPUAS.REGION_ADDRESS)
-      continue;
-
-    recursivelyVisitUsers(GV, FuncsToAlwaysInline);
-  }
+  auto NewAttr = StressCalls ? Attribute::NoInline : Attribute::AlwaysInline;
+  auto IncompatAttr
+    = StressCalls ? Attribute::AlwaysInline : Attribute::NoInline;
 
-  if (!AMDGPUTargetMachine::EnableFunctionCalls || StressCalls) {
-    auto IncompatAttr
-      = StressCalls ? Attribute::AlwaysInline : Attribute::NoInline;
-
-    for (Function &F : M) {
-      if (!F.isDeclaration() && !F.use_empty() &&
-          !F.hasFnAttribute(IncompatAttr)) {
-        if (StressCalls) {
-          if (!FuncsToAlwaysInline.count(&F))
-            FuncsToNoInline.insert(&F);
-        } else
-          FuncsToAlwaysInline.insert(&F);
-      }
-    }
+  for (Function &F : M) {
+    if (!F.hasLocalLinkage() && !F.isDeclaration() && !F.use_empty() &&
+        !F.hasFnAttribute(IncompatAttr))
+      FuncsToClone.push_back(&F);
   }
 
-  for (Function *F : FuncsToAlwaysInline)
-    F->addFnAttr(Attribute::AlwaysInline);
-
-  for (Function *F : FuncsToNoInline)
-    F->addFnAttr(Attribute::NoInline);
+  for (Function *F : FuncsToClone) {
+    ValueToValueMapTy VMap;
+    Function *NewFunc = CloneFunction(F, VMap);
+    NewFunc->setLinkage(GlobalValue::InternalLinkage);
+    F->replaceAllUsesWith(NewFunc);
+  }
 
-  return !FuncsToAlwaysInline.empty() || !FuncsToNoInline.empty();
+  for (Function &F : M) {
+    if (F.hasLocalLinkage() && !F.hasFnAttribute(IncompatAttr)) {
+      F.addFnAttr(NewAttr);
+    }
+  }
+  return false;
 }
 
 ModulePass *llvm::createAMDGPUAlwaysInlinePass(bool GlobalOpt) {
   return new AMDGPUAlwaysInline(GlobalOpt);
 }
-