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, 8 insertions, 7 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 68ecd516049..ff758c40af3 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1068,7 +1068,7 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
         // If the bitcast is of an allocation, and the allocation will be
         // converted to match the type of the cast, don't touch this.
         if (isa<AllocaInst>(BCI->getOperand(0)) ||
-            isAllocationFn(BCI->getOperand(0))) {
+            isAllocationFn(BCI->getOperand(0), TLI)) {
           // See if the bitcast simplifies, if so, don't nuke this GEP yet.
           if (Instruction *I = visitBitCast(*BCI)) {
             if (I != BCI) {
@@ -1107,7 +1107,8 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
 
 
 static bool
-isAllocSiteRemovable(Instruction *AI, SmallVectorImpl<WeakVH> &Users) {
+isAllocSiteRemovable(Instruction *AI, SmallVectorImpl<WeakVH> &Users,
+                     const TargetLibraryInfo *TLI) {
   SmallVector<Instruction*, 4> Worklist;
   Worklist.push_back(AI);
 
@@ -1163,7 +1164,7 @@ isAllocSiteRemovable(Instruction *AI, SmallVectorImpl<WeakVH> &Users) {
           }
         }
 
-        if (isFreeCall(I)) {
+        if (isFreeCall(I, TLI)) {
           Users.push_back(I);
           continue;
         }
@@ -1188,7 +1189,7 @@ Instruction *InstCombiner::visitAllocSite(Instruction &MI) {
   // to null and free calls, delete the calls and replace the comparisons with
   // true or false as appropriate.
   SmallVector<WeakVH, 64> Users;
-  if (isAllocSiteRemovable(&MI, Users)) {
+  if (isAllocSiteRemovable(&MI, Users, TLI)) {
     for (unsigned i = 0, e = Users.size(); i != e; ++i) {
       Instruction *I = cast_or_null<Instruction>(&*Users[i]);
       if (!I) continue;
@@ -1872,7 +1873,7 @@ static bool AddReachableCodeToWorklist(BasicBlock *BB,
       Instruction *Inst = BBI++;
 
       // DCE instruction if trivially dead.
-      if (isInstructionTriviallyDead(Inst)) {
+      if (isInstructionTriviallyDead(Inst, TLI)) {
         ++NumDeadInst;
         DEBUG(errs() << "IC: DCE: " << *Inst << '\n');
         Inst->eraseFromParent();
@@ -2002,7 +2003,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) {
     if (I == 0) continue;  // skip null values.
 
     // Check to see if we can DCE the instruction.
-    if (isInstructionTriviallyDead(I)) {
+    if (isInstructionTriviallyDead(I, TLI)) {
       DEBUG(errs() << "IC: DCE: " << *I << '\n');
       EraseInstFromFunction(*I);
       ++NumDeadInst;
@@ -2102,7 +2103,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) {
 
         // If the instruction was modified, it's possible that it is now dead.
         // if so, remove it.
-        if (isInstructionTriviallyDead(I)) {
+        if (isInstructionTriviallyDead(I, TLI)) {
           EraseInstFromFunction(*I);
         } else {
           Worklist.Add(I);