Rewrite objc intrinsics to runtime methods in PreISelIntrinsicLowering instead of SDAG.

SelectionDAG currently changes these intrinsics to function calls, but that won't work
for other ISel's.  Also we want to eventually support nonlazybind and weak linkage coming
from the front-end which we can't do in SelectionDAG.

llvm-svn: 349552

2 files changed, 112 insertions, 52 deletions

diff --git a/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp b/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
index 8f88ef78828..cd15f6b7fcb 100644
--- a/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
+++ b/llvm/lib/CodeGen/PreISelIntrinsicLowering.cpp
@@ -7,13 +7,15 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This pass implements IR lowering for the llvm.load.relative intrinsic.
+// This pass implements IR lowering for the llvm.load.relative and llvm.objc.*
+// intrinsics.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/PreISelIntrinsicLowering.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Module.h"
@@ -55,11 +57,119 @@ static bool lowerLoadRelative(Function &F) {
   return Changed;
 }
 
+static bool lowerObjCCall(Function &F, const char *NewFn) {
+  if (F.use_empty())
+    return false;
+
+  // If we haven't already looked up this function, check to see if the
+  // program already contains a function with this name.
+  Module *M = F.getParent();
+  Constant* FCache = M->getOrInsertFunction(NewFn, F.getFunctionType());
+
+  for (auto I = F.use_begin(), E = F.use_end(); I != E;) {
+    auto *CI = dyn_cast<CallInst>(I->getUser());
+    assert(CI->getCalledFunction() && "Cannot lower an indirect call!");
+    ++I;
+
+    IRBuilder<> Builder(CI->getParent(), CI->getIterator());
+    SmallVector<Value *, 8> Args(CI->arg_begin(), CI->arg_end());
+    CallInst *NewCI = Builder.CreateCall(FCache, Args);
+    NewCI->setName(CI->getName());
+    NewCI->setTailCallKind(CI->getTailCallKind());
+    if (!CI->use_empty())
+      CI->replaceAllUsesWith(NewCI);
+    CI->eraseFromParent();
+  }
+
+  return true;
+}
+
 static bool lowerIntrinsics(Module &M) {
   bool Changed = false;
   for (Function &F : M) {
-    if (F.getName().startswith("llvm.load.relative."))
+    if (F.getName().startswith("llvm.load.relative.")) {
       Changed |= lowerLoadRelative(F);
+      continue;
+    }
+    switch (F.getIntrinsicID()) {
+    default:
+      break;
+    case Intrinsic::objc_autorelease:
+      Changed |= lowerObjCCall(F, "objc_autorelease");
+      break;
+    case Intrinsic::objc_autoreleasePoolPop:
+      Changed |= lowerObjCCall(F, "objc_autoreleasePoolPop");
+      break;
+    case Intrinsic::objc_autoreleasePoolPush:
+      Changed |= lowerObjCCall(F, "objc_autoreleasePoolPush");
+      break;
+    case Intrinsic::objc_autoreleaseReturnValue:
+      Changed |= lowerObjCCall(F, "objc_autoreleaseReturnValue");
+      break;
+    case Intrinsic::objc_copyWeak:
+      Changed |= lowerObjCCall(F, "objc_copyWeak");
+      break;
+    case Intrinsic::objc_destroyWeak:
+      Changed |= lowerObjCCall(F, "objc_destroyWeak");
+      break;
+    case Intrinsic::objc_initWeak:
+      Changed |= lowerObjCCall(F, "objc_initWeak");
+      break;
+    case Intrinsic::objc_loadWeak:
+      Changed |= lowerObjCCall(F, "objc_loadWeak");
+      break;
+    case Intrinsic::objc_loadWeakRetained:
+      Changed |= lowerObjCCall(F, "objc_loadWeakRetained");
+      break;
+    case Intrinsic::objc_moveWeak:
+      Changed |= lowerObjCCall(F, "objc_moveWeak");
+      break;
+    case Intrinsic::objc_release:
+      Changed |= lowerObjCCall(F, "objc_release");
+      break;
+    case Intrinsic::objc_retain:
+      Changed |= lowerObjCCall(F, "objc_retain");
+      break;
+    case Intrinsic::objc_retainAutorelease:
+      Changed |= lowerObjCCall(F, "objc_retainAutorelease");
+      break;
+    case Intrinsic::objc_retainAutoreleaseReturnValue:
+      Changed |= lowerObjCCall(F, "objc_retainAutoreleaseReturnValue");
+      break;
+    case Intrinsic::objc_retainAutoreleasedReturnValue:
+      Changed |= lowerObjCCall(F, "objc_retainAutoreleasedReturnValue");
+      break;
+    case Intrinsic::objc_retainBlock:
+      Changed |= lowerObjCCall(F, "objc_retainBlock");
+      break;
+    case Intrinsic::objc_storeStrong:
+      Changed |= lowerObjCCall(F, "objc_storeStrong");
+      break;
+    case Intrinsic::objc_storeWeak:
+      Changed |= lowerObjCCall(F, "objc_storeWeak");
+      break;
+    case Intrinsic::objc_unsafeClaimAutoreleasedReturnValue:
+      Changed |= lowerObjCCall(F, "objc_unsafeClaimAutoreleasedReturnValue");
+      break;
+    case Intrinsic::objc_retainedObject:
+      Changed |= lowerObjCCall(F, "objc_retainedObject");
+      break;
+    case Intrinsic::objc_unretainedObject:
+      Changed |= lowerObjCCall(F, "objc_unretainedObject");
+      break;
+    case Intrinsic::objc_unretainedPointer:
+      Changed |= lowerObjCCall(F, "objc_unretainedPointer");
+      break;
+    case Intrinsic::objc_retain_autorelease:
+      Changed |= lowerObjCCall(F, "objc_retain_autorelease");
+      break;
+    case Intrinsic::objc_sync_enter:
+      Changed |= lowerObjCCall(F, "objc_sync_enter");
+      break;
+    case Intrinsic::objc_sync_exit:
+      Changed |= lowerObjCCall(F, "objc_sync_exit");
+      break;
+    }
   }
   return Changed;
 }
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index cf06c1f0b4b..c42d2491243 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -6363,56 +6363,6 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
     // MachineFunction in SelectionDAGISel::PrepareEHLandingPad. We can safely
     // delete it now.
     return nullptr;
-  case Intrinsic::objc_autorelease:
-    return "objc_autorelease";
-  case Intrinsic::objc_autoreleasePoolPop:
-    return "objc_autoreleasePoolPop";
-  case Intrinsic::objc_autoreleasePoolPush:
-    return "objc_autoreleasePoolPush";
-  case Intrinsic::objc_autoreleaseReturnValue:
-    return "objc_autoreleaseReturnValue";
-  case Intrinsic::objc_copyWeak:
-    return "objc_copyWeak";
-  case Intrinsic::objc_destroyWeak:
-    return "objc_destroyWeak";
-  case Intrinsic::objc_initWeak:
-    return "objc_initWeak";
-  case Intrinsic::objc_loadWeak:
-    return "objc_loadWeak";
-  case Intrinsic::objc_loadWeakRetained:
-    return "objc_loadWeakRetained";
-  case Intrinsic::objc_moveWeak:
-    return "objc_moveWeak";
-  case Intrinsic::objc_release:
-    return "objc_release";
-  case Intrinsic::objc_retain:
-    return "objc_retain";
-  case Intrinsic::objc_retainAutorelease:
-    return "objc_retainAutorelease";
-  case Intrinsic::objc_retainAutoreleaseReturnValue:
-    return "objc_retainAutoreleaseReturnValue";
-  case Intrinsic::objc_retainAutoreleasedReturnValue:
-    return "objc_retainAutoreleasedReturnValue";
-  case Intrinsic::objc_retainBlock:
-    return "objc_retainBlock";
-  case Intrinsic::objc_storeStrong:
-    return "objc_storeStrong";
-  case Intrinsic::objc_storeWeak:
-    return "objc_storeWeak";
-  case Intrinsic::objc_unsafeClaimAutoreleasedReturnValue:
-    return "objc_unsafeClaimAutoreleasedReturnValue";
-  case Intrinsic::objc_retainedObject:
-    return "objc_retainedObject";
-  case Intrinsic::objc_unretainedObject:
-    return "objc_unretainedObject";
-  case Intrinsic::objc_unretainedPointer:
-    return "objc_unretainedPointer";
-  case Intrinsic::objc_retain_autorelease:
-    return "objc_retain_autorelease";
-  case Intrinsic::objc_sync_enter:
-    return "objc_sync_enter";
-  case Intrinsic::objc_sync_exit:
-    return "objc_sync_exit";
   }
 }