Make MemoryBuiltins aware of TargetLibraryInfo.

This disables malloc-specific optimization when -fno-builtin (or -ffreestanding)
is specified. This has been a problem for a long time but became more severe
with the recent memory builtin improvements.

Since the memory builtin functions are used everywhere, this required passing
TLI in many places. This means that functions that now have an optional TLI
argument, like RecursivelyDeleteTriviallyDeadFunctions, won't remove dead
mallocs anymore if the TLI argument is missing. I've updated most passes to do
the right thing.

Fixes PR13694 and probably others.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162841 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 21 insertions, 15 deletions

diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index bed7d72fff..0601433565 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -52,7 +52,8 @@ using namespace llvm;
 /// Also calls RecursivelyDeleteTriviallyDeadInstructions() on any branch/switch
 /// conditions and indirectbr addresses this might make dead if
 /// DeleteDeadConditions is true.
-bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions) {
+bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions,
+                                  const TargetLibraryInfo *TLI) {
   TerminatorInst *T = BB->getTerminator();
   IRBuilder<> Builder(T);
 
@@ -96,7 +97,7 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions) {
       Value *Cond = BI->getCondition();
       BI->eraseFromParent();
       if (DeleteDeadConditions)
-        RecursivelyDeleteTriviallyDeadInstructions(Cond);
+        RecursivelyDeleteTriviallyDeadInstructions(Cond, TLI);
       return true;
     }
     return false;
@@ -161,7 +162,7 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions) {
       Value *Cond = SI->getCondition();
       SI->eraseFromParent();
       if (DeleteDeadConditions)
-        RecursivelyDeleteTriviallyDeadInstructions(Cond);
+        RecursivelyDeleteTriviallyDeadInstructions(Cond, TLI);
       return true;
     }
     
@@ -205,7 +206,7 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions) {
       Value *Address = IBI->getAddress();
       IBI->eraseFromParent();
       if (DeleteDeadConditions)
-        RecursivelyDeleteTriviallyDeadInstructions(Address);
+        RecursivelyDeleteTriviallyDeadInstructions(Address, TLI);
       
       // If we didn't find our destination in the IBI successor list, then we
       // have undefined behavior.  Replace the unconditional branch with an
@@ -230,7 +231,8 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB, bool DeleteDeadConditions) {
 /// isInstructionTriviallyDead - Return true if the result produced by the
 /// instruction is not used, and the instruction has no side effects.
 ///
-bool llvm::isInstructionTriviallyDead(Instruction *I) {
+bool llvm::isInstructionTriviallyDead(Instruction *I,
+                                      const TargetLibraryInfo *TLI) {
   if (!I->use_empty() || isa<TerminatorInst>(I)) return false;
 
   // We don't want the landingpad instruction removed by anything this general.
@@ -265,9 +267,9 @@ bool llvm::isInstructionTriviallyDead(Instruction *I) {
       return isa<UndefValue>(II->getArgOperand(1));
   }
 
-  if (isAllocLikeFn(I)) return true;
+  if (isAllocLikeFn(I, TLI)) return true;
 
-  if (CallInst *CI = isFreeCall(I))
+  if (CallInst *CI = isFreeCall(I, TLI))
     if (Constant *C = dyn_cast<Constant>(CI->getArgOperand(0)))
       return C->isNullValue() || isa<UndefValue>(C);
 
@@ -278,9 +280,11 @@ bool llvm::isInstructionTriviallyDead(Instruction *I) {
 /// trivially dead instruction, delete it.  If that makes any of its operands
 /// trivially dead, delete them too, recursively.  Return true if any
 /// instructions were deleted.
-bool llvm::RecursivelyDeleteTriviallyDeadInstructions(Value *V) {
+bool
+llvm::RecursivelyDeleteTriviallyDeadInstructions(Value *V,
+                                                 const TargetLibraryInfo *TLI) {
   Instruction *I = dyn_cast<Instruction>(V);
-  if (!I || !I->use_empty() || !isInstructionTriviallyDead(I))
+  if (!I || !I->use_empty() || !isInstructionTriviallyDead(I, TLI))
     return false;
   
   SmallVector<Instruction*, 16> DeadInsts;
@@ -301,7 +305,7 @@ bool llvm::RecursivelyDeleteTriviallyDeadInstructions(Value *V) {
       // operand, and if it is 'trivially' dead, delete it in a future loop
       // iteration.
       if (Instruction *OpI = dyn_cast<Instruction>(OpV))
-        if (isInstructionTriviallyDead(OpI))
+        if (isInstructionTriviallyDead(OpI, TLI))
           DeadInsts.push_back(OpI);
     }
     
@@ -334,19 +338,20 @@ static bool areAllUsesEqual(Instruction *I) {
 /// either forms a cycle or is terminated by a trivially dead instruction,
 /// delete it.  If that makes any of its operands trivially dead, delete them
 /// too, recursively.  Return true if a change was made.
-bool llvm::RecursivelyDeleteDeadPHINode(PHINode *PN) {
+bool llvm::RecursivelyDeleteDeadPHINode(PHINode *PN,
+                                        const TargetLibraryInfo *TLI) {
   SmallPtrSet<Instruction*, 4> Visited;
   for (Instruction *I = PN; areAllUsesEqual(I) && !I->mayHaveSideEffects();
        I = cast<Instruction>(*I->use_begin())) {
     if (I->use_empty())
-      return RecursivelyDeleteTriviallyDeadInstructions(I);
+      return RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
 
     // If we find an instruction more than once, we're on a cycle that
     // won't prove fruitful.
     if (!Visited.insert(I)) {
       // Break the cycle and delete the instruction and its operands.
       I->replaceAllUsesWith(UndefValue::get(I->getType()));
-      (void)RecursivelyDeleteTriviallyDeadInstructions(I);
+      (void)RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
       return true;
     }
   }
@@ -358,7 +363,8 @@ bool llvm::RecursivelyDeleteDeadPHINode(PHINode *PN) {
 ///
 /// This returns true if it changed the code, note that it can delete
 /// instructions in other blocks as well in this block.
-bool llvm::SimplifyInstructionsInBlock(BasicBlock *BB, const TargetData *TD) {
+bool llvm::SimplifyInstructionsInBlock(BasicBlock *BB, const TargetData *TD,
+                                       const TargetLibraryInfo *TLI) {
   bool MadeChange = false;
 
 #ifndef NDEBUG
@@ -381,7 +387,7 @@ bool llvm::SimplifyInstructionsInBlock(BasicBlock *BB, const TargetData *TD) {
       continue;
     }
 
-    MadeChange |= RecursivelyDeleteTriviallyDeadInstructions(Inst);
+    MadeChange |= RecursivelyDeleteTriviallyDeadInstructions(Inst, TLI);
     if (BIHandle != BI)
       BI = BB->begin();
   }