Rip out support for 'llvm.noinline'. This thing has a strange history...

It was added in 2007 as the first cut at supporting no-inline
attributes, but we didn't have function attributes of any form at the
time. However, it was added without any mention in the LangRef or other
documentation.

Later on, in 2008, Devang added function notes for 'inline=never' and
then turned them into proper function attributes. From that point
onward, as far as I can tell, the world moved on, and no one has touched
'llvm.noinline' in any meaningful way since.

It's time has now come. We have had better mechanisms for doing this for
a long time, all the frontends I'm aware of use them, and this is just
holding back progress. Given that it was never a documented feature of
the IR, I've provided no auto-upgrade support. If people know of real,
in-the-wild bitcode that relies on this, yell at me and I'll add it, but
I *seriously* doubt anyone cares.

llvm-svn: 152904

1 files changed, 0 insertions, 45 deletions

diff --git a/llvm/lib/Transforms/IPO/InlineSimple.cpp b/llvm/lib/Transforms/IPO/InlineSimple.cpp
index a7aeed8..03032e6 100644
--- a/llvm/lib/Transforms/IPO/InlineSimple.cpp
+++ b/llvm/lib/Transforms/IPO/InlineSimple.cpp
@@ -23,15 +23,12 @@
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/IPO/InlinerPass.h"
 #include "llvm/Target/TargetData.h"
-#include "llvm/ADT/SmallPtrSet.h"
 
 using namespace llvm;
 
 namespace {
 
   class SimpleInliner : public Inliner {
-    // Functions that are never inlined
-    SmallPtrSet<const Function*, 16> NeverInline;
     InlineCostAnalyzer CA;
   public:
     SimpleInliner() : Inliner(ID) {
@@ -43,15 +40,6 @@ namespace {
     }
     static char ID; // Pass identification, replacement for typeid
     InlineCost getInlineCost(CallSite CS) {
-      // Filter out functions which should never be inlined due to the global
-      // 'llvm.noinline'.
-      // FIXME: I'm 99% certain that this is an ancient bit of legacy that we
-      // no longer need to support, but I don't want to blindly nuke it just
-      // yet.
-      if (Function *Callee = CS.getCalledFunction())
-        if (NeverInline.count(Callee))
-          return InlineCost::getNever();
-
       return CA.getInlineCost(CS);
     }
     float getInlineFudgeFactor(CallSite CS) {
@@ -87,39 +75,6 @@ Pass *llvm::createFunctionInliningPass(int Threshold) {
 // annotated with the noinline attribute.
 bool SimpleInliner::doInitialization(CallGraph &CG) {
   CA.setTargetData(getAnalysisIfAvailable<TargetData>());
-
-  Module &M = CG.getModule();
-
-  // Get llvm.noinline
-  GlobalVariable *GV = M.getNamedGlobal("llvm.noinline");
-
-  if (GV == 0)
-    return false;
-
-  // Don't crash on invalid code
-  if (!GV->hasDefinitiveInitializer())
-    return false;
-
-  const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
-
-  if (InitList == 0)
-    return false;
-
-  // Iterate over each element and add to the NeverInline set
-  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
-
-    // Get Source
-    const Constant *Elt = InitList->getOperand(i);
-
-    if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt))
-      if (CE->getOpcode() == Instruction::BitCast)
-        Elt = CE->getOperand(0);
-
-    // Insert into set of functions to never inline
-    if (const Function *F = dyn_cast<Function>(Elt))
-      NeverInline.insert(F);
-  }
-
   return false;
 }