Remove the hack to check UNAME_RELEASE when identifying the Darwin version.

[oota-llvm.git] / lib / Transforms / Utils / Local.cpp

diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index 00469454851520093f3c4ff28ca8ab5973d92d20..be0aa82500160abd31ff692dcf88e9ee11574a84 100644 (file)
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -27,7 +27,6 @@
 #include "llvm/Analysis/DebugInfo.h"
 #include "llvm/Analysis/DIBuilder.h"
 #include "llvm/Analysis/Dominators.h"
-#include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/ProfileInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
@@ -227,13 +226,17 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions) {
 bool llvm::isInstructionTriviallyDead(Instruction *I) {
   if (!I->use_empty() || isa<TerminatorInst>(I)) return false;
 
+  // We don't want the landingpad instruction removed by anything this general.
+  if (isa<LandingPadInst>(I))
+    return false;
+
   // We don't want debug info removed by anything this general, unless
   // debug info is empty.
   if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(I)) {
-    if (DDI->getAddress()) 
+    if (DDI->getAddress())
       return false;
     return true;
-  } 
+  }
   if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(I)) {
     if (DVI->getValue())
       return false;
@@ -244,10 +247,16 @@ bool llvm::isInstructionTriviallyDead(Instruction *I) {
 
   // Special case intrinsics that "may have side effects" but can be deleted
   // when dead.
-  if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
+  if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
     // Safe to delete llvm.stacksave if dead.
     if (II->getIntrinsicID() == Intrinsic::stacksave)
       return true;
+
+    // Lifetime intrinsics are dead when their right-hand is undef.
+    if (II->getIntrinsicID() == Intrinsic::lifetime_start ||
+        II->getIntrinsicID() == Intrinsic::lifetime_end)
+      return isa<UndefValue>(II->getArgOperand(1));
+  }
   return false;
 }
 
@@ -619,7 +628,7 @@ bool llvm::TryToSimplifyUncondBranchFromEmptyBlock(BasicBlock *BB) {
 
     // Copy over any phi, debug or lifetime instruction.
     BB->getTerminator()->eraseFromParent();
-    Succ->getInstList().splice(Succ->begin(), BB->getInstList());
+    Succ->getInstList().splice(Succ->getFirstNonPHI(), BB->getInstList());
   } else {
     while (PHINode *PN = dyn_cast<PHINode>(&BB->front())) {
       // We explicitly check for such uses in CanPropagatePredecessorsForPHIs.