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.

llvm-svn: 162841

1 files changed, 13 insertions, 11 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
index ac1082cbfbd..a72e288303f 100644
--- a/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
@@ -132,7 +132,8 @@ Pass *llvm::createLoopIdiomPass() { return new LoopIdiomRecognize(); }
 /// and zero out all the operands of this instruction.  If any of them become
 /// dead, delete them and the computation tree that feeds them.
 ///
-static void deleteDeadInstruction(Instruction *I, ScalarEvolution &SE) {
+static void deleteDeadInstruction(Instruction *I, ScalarEvolution &SE,
+                                  const TargetLibraryInfo *TLI) {
   SmallVector<Instruction*, 32> NowDeadInsts;
 
   NowDeadInsts.push_back(I);
@@ -153,7 +154,7 @@ static void deleteDeadInstruction(Instruction *I, ScalarEvolution &SE) {
       if (!Op->use_empty()) continue;
 
       if (Instruction *OpI = dyn_cast<Instruction>(Op))
-        if (isInstructionTriviallyDead(OpI))
+        if (isInstructionTriviallyDead(OpI, TLI))
           NowDeadInsts.push_back(OpI);
     }
 
@@ -164,10 +165,11 @@ static void deleteDeadInstruction(Instruction *I, ScalarEvolution &SE) {
 
 /// deleteIfDeadInstruction - If the specified value is a dead instruction,
 /// delete it and any recursively used instructions.
-static void deleteIfDeadInstruction(Value *V, ScalarEvolution &SE) {
+static void deleteIfDeadInstruction(Value *V, ScalarEvolution &SE,
+                                    const TargetLibraryInfo *TLI) {
   if (Instruction *I = dyn_cast<Instruction>(V))
-    if (isInstructionTriviallyDead(I))
-      deleteDeadInstruction(I, SE);
+    if (isInstructionTriviallyDead(I, TLI))
+      deleteDeadInstruction(I, SE, TLI);
 }
 
 bool LoopIdiomRecognize::runOnLoop(Loop *L, LPPassManager &LPM) {
@@ -490,7 +492,7 @@ processLoopStridedStore(Value *DestPtr, unsigned StoreSize,
                             StoreSize, getAnalysis<AliasAnalysis>(), TheStore)){
     Expander.clear();
     // If we generated new code for the base pointer, clean up.
-    deleteIfDeadInstruction(BasePtr, *SE);
+    deleteIfDeadInstruction(BasePtr, *SE, TLI);
     return false;
   }
 
@@ -538,7 +540,7 @@ processLoopStridedStore(Value *DestPtr, unsigned StoreSize,
 
   // Okay, the memset has been formed.  Zap the original store and anything that
   // feeds into it.
-  deleteDeadInstruction(TheStore, *SE);
+  deleteDeadInstruction(TheStore, *SE, TLI);
   ++NumMemSet;
   return true;
 }
@@ -579,7 +581,7 @@ processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
                             getAnalysis<AliasAnalysis>(), SI)) {
     Expander.clear();
     // If we generated new code for the base pointer, clean up.
-    deleteIfDeadInstruction(StoreBasePtr, *SE);
+    deleteIfDeadInstruction(StoreBasePtr, *SE, TLI);
     return false;
   }
 
@@ -594,8 +596,8 @@ processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
                             StoreSize, getAnalysis<AliasAnalysis>(), SI)) {
     Expander.clear();
     // If we generated new code for the base pointer, clean up.
-    deleteIfDeadInstruction(LoadBasePtr, *SE);
-    deleteIfDeadInstruction(StoreBasePtr, *SE);
+    deleteIfDeadInstruction(LoadBasePtr, *SE, TLI);
+    deleteIfDeadInstruction(StoreBasePtr, *SE, TLI);
     return false;
   }
 
@@ -628,7 +630,7 @@ processLoopStoreOfLoopLoad(StoreInst *SI, unsigned StoreSize,
 
   // Okay, the memset has been formed.  Zap the original store and anything that
   // feeds into it.
-  deleteDeadInstruction(SI, *SE);
+  deleteDeadInstruction(SI, *SE, TLI);
   ++NumMemCpy;
   return true;
 }