Import LLVM 8.0.0 release including clang, lld and lldb.

1 files changed, 65 insertions, 84 deletions

diff --git a/gnu/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/gnu/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index 62769f077b4..76ab614090f 100644
--- a/gnu/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/gnu/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -19,6 +19,7 @@
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/IR/ConstantRange.h"
 #include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/MDBuilder.h"
@@ -115,13 +116,10 @@ isOnlyCopiedFromConstantGlobal(Value *V, MemTransferInst *&TheCopy,
       }
 
       // Lifetime intrinsics can be handled by the caller.
-      if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) {
-        if (II->getIntrinsicID() == Intrinsic::lifetime_start ||
-            II->getIntrinsicID() == Intrinsic::lifetime_end) {
-          assert(II->use_empty() && "Lifetime markers have no result to use!");
-          ToDelete.push_back(II);
-          continue;
-        }
+      if (I->isLifetimeStartOrEnd()) {
+        assert(I->use_empty() && "Lifetime markers have no result to use!");
+        ToDelete.push_back(I);
+        continue;
       }
 
       // If this is isn't our memcpy/memmove, reject it as something we can't
@@ -197,30 +195,32 @@ static Instruction *simplifyAllocaArraySize(InstCombiner &IC, AllocaInst &AI) {
 
   // Convert: alloca Ty, C - where C is a constant != 1 into: alloca [C x Ty], 1
   if (const ConstantInt *C = dyn_cast<ConstantInt>(AI.getArraySize())) {
-    Type *NewTy = ArrayType::get(AI.getAllocatedType(), C->getZExtValue());
-    AllocaInst *New = IC.Builder.CreateAlloca(NewTy, nullptr, AI.getName());
-    New->setAlignment(AI.getAlignment());
-
-    // Scan to the end of the allocation instructions, to skip over a block of
-    // allocas if possible...also skip interleaved debug info
-    //
-    BasicBlock::iterator It(New);
-    while (isa<AllocaInst>(*It) || isa<DbgInfoIntrinsic>(*It))
-      ++It;
-
-    // Now that I is pointing to the first non-allocation-inst in the block,
-    // insert our getelementptr instruction...
-    //
-    Type *IdxTy = IC.getDataLayout().getIntPtrType(AI.getType());
-    Value *NullIdx = Constant::getNullValue(IdxTy);
-    Value *Idx[2] = {NullIdx, NullIdx};
-    Instruction *GEP =
-        GetElementPtrInst::CreateInBounds(New, Idx, New->getName() + ".sub");
-    IC.InsertNewInstBefore(GEP, *It);
-
-    // Now make everything use the getelementptr instead of the original
-    // allocation.
-    return IC.replaceInstUsesWith(AI, GEP);
+    if (C->getValue().getActiveBits() <= 64) {
+      Type *NewTy = ArrayType::get(AI.getAllocatedType(), C->getZExtValue());
+      AllocaInst *New = IC.Builder.CreateAlloca(NewTy, nullptr, AI.getName());
+      New->setAlignment(AI.getAlignment());
+
+      // Scan to the end of the allocation instructions, to skip over a block of
+      // allocas if possible...also skip interleaved debug info
+      //
+      BasicBlock::iterator It(New);
+      while (isa<AllocaInst>(*It) || isa<DbgInfoIntrinsic>(*It))
+        ++It;
+
+      // Now that I is pointing to the first non-allocation-inst in the block,
+      // insert our getelementptr instruction...
+      //
+      Type *IdxTy = IC.getDataLayout().getIntPtrType(AI.getType());
+      Value *NullIdx = Constant::getNullValue(IdxTy);
+      Value *Idx[2] = {NullIdx, NullIdx};
+      Instruction *GEP =
+          GetElementPtrInst::CreateInBounds(New, Idx, New->getName() + ".sub");
+      IC.InsertNewInstBefore(GEP, *It);
+
+      // Now make everything use the getelementptr instead of the original
+      // allocation.
+      return IC.replaceInstUsesWith(AI, GEP);
+    }
   }
 
   if (isa<UndefValue>(AI.getArraySize()))
@@ -490,6 +490,7 @@ static LoadInst *combineLoadToNewType(InstCombiner &IC, LoadInst &LI, Type *NewT
     case LLVMContext::MD_noalias:
     case LLVMContext::MD_nontemporal:
     case LLVMContext::MD_mem_parallel_loop_access:
+    case LLVMContext::MD_access_group:
       // All of these directly apply.
       NewLoad->setMetadata(ID, N);
       break;
@@ -549,10 +550,10 @@ static StoreInst *combineStoreToNewValue(InstCombiner &IC, StoreInst &SI, Value
     case LLVMContext::MD_noalias:
     case LLVMContext::MD_nontemporal:
     case LLVMContext::MD_mem_parallel_loop_access:
+    case LLVMContext::MD_access_group:
       // All of these directly apply.
       NewStore->setMetadata(ID, N);
       break;
-
     case LLVMContext::MD_invariant_load:
     case LLVMContext::MD_nonnull:
     case LLVMContext::MD_range:
@@ -1024,7 +1025,7 @@ Instruction *InstCombiner::visitLoadInst(LoadInst &LI) {
   if (Value *AvailableVal = FindAvailableLoadedValue(
           &LI, LI.getParent(), BBI, DefMaxInstsToScan, AA, &IsLoadCSE)) {
     if (IsLoadCSE)
-      combineMetadataForCSE(cast<LoadInst>(AvailableVal), &LI);
+      combineMetadataForCSE(cast<LoadInst>(AvailableVal), &LI, false);
 
     return replaceInstUsesWith(
         LI, Builder.CreateBitOrPointerCast(AvailableVal, LI.getType(),
@@ -1496,64 +1497,45 @@ Instruction *InstCombiner::visitStoreInst(StoreInst &SI) {
   if (isa<UndefValue>(Val))
     return eraseInstFromFunction(SI);
 
-  // If this store is the last instruction in the basic block (possibly
-  // excepting debug info instructions), and if the block ends with an
-  // unconditional branch, try to move it to the successor block.
+  // If this store is the second-to-last instruction in the basic block
+  // (excluding debug info and bitcasts of pointers) and if the block ends with
+  // an unconditional branch, try to move the store to the successor block.
   BBI = SI.getIterator();
   do {
     ++BBI;
   } while (isa<DbgInfoIntrinsic>(BBI) ||
            (isa<BitCastInst>(BBI) && BBI->getType()->isPointerTy()));
+
   if (BranchInst *BI = dyn_cast<BranchInst>(BBI))
     if (BI->isUnconditional())
-      if (SimplifyStoreAtEndOfBlock(SI))
-        return nullptr;  // xform done!
+      mergeStoreIntoSuccessor(SI);
 
   return nullptr;
 }
 
-/// SimplifyStoreAtEndOfBlock - Turn things like:
+/// Try to transform:
 ///   if () { *P = v1; } else { *P = v2 }
-/// into a phi node with a store in the successor.
-///
-/// Simplify things like:
+/// or:
 ///   *P = v1; if () { *P = v2; }
 /// into a phi node with a store in the successor.
-///
-bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) {
+bool InstCombiner::mergeStoreIntoSuccessor(StoreInst &SI) {
   assert(SI.isUnordered() &&
-         "this code has not been auditted for volatile or ordered store case");
+         "This code has not been audited for volatile or ordered store case.");
 
+  // Check if the successor block has exactly 2 incoming edges.
   BasicBlock *StoreBB = SI.getParent();
-
-  // Check to see if the successor block has exactly two incoming edges.  If
-  // so, see if the other predecessor contains a store to the same location.
-  // if so, insert a PHI node (if needed) and move the stores down.
   BasicBlock *DestBB = StoreBB->getTerminator()->getSuccessor(0);
-
-  // Determine whether Dest has exactly two predecessors and, if so, compute
-  // the other predecessor.
-  pred_iterator PI = pred_begin(DestBB);
-  BasicBlock *P = *PI;
-  BasicBlock *OtherBB = nullptr;
-
-  if (P != StoreBB)
-    OtherBB = P;
-
-  if (++PI == pred_end(DestBB))
+  if (!DestBB->hasNPredecessors(2))
     return false;
 
-  P = *PI;
-  if (P != StoreBB) {
-    if (OtherBB)
-      return false;
-    OtherBB = P;
-  }
-  if (++PI != pred_end(DestBB))
-    return false;
+  // Capture the other block (the block that doesn't contain our store).
+  pred_iterator PredIter = pred_begin(DestBB);
+  if (*PredIter == StoreBB)
+    ++PredIter;
+  BasicBlock *OtherBB = *PredIter;
 
-  // Bail out if all the relevant blocks aren't distinct (this can happen,
-  // for example, if SI is in an infinite loop)
+  // Bail out if all of the relevant blocks aren't distinct. This can happen,
+  // for example, if SI is in an infinite loop.
   if (StoreBB == DestBB || OtherBB == DestBB)
     return false;
 
@@ -1564,7 +1546,7 @@ bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) {
     return false;
 
   // If the other block ends in an unconditional branch, check for the 'if then
-  // else' case.  there is an instruction before the branch.
+  // else' case. There is an instruction before the branch.
   StoreInst *OtherStore = nullptr;
   if (OtherBr->isUnconditional()) {
     --BBI;
@@ -1589,7 +1571,7 @@ bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) {
       return false;
 
     // Okay, we know that OtherBr now goes to Dest and StoreBB, so this is an
-    // if/then triangle.  See if there is a store to the same ptr as SI that
+    // if/then triangle. See if there is a store to the same ptr as SI that
     // lives in OtherBB.
     for (;; --BBI) {
       // Check to see if we find the matching store.
@@ -1600,15 +1582,14 @@ bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) {
         break;
       }
       // If we find something that may be using or overwriting the stored
-      // value, or if we run out of instructions, we can't do the xform.
+      // value, or if we run out of instructions, we can't do the transform.
       if (BBI->mayReadFromMemory() || BBI->mayThrow() ||
           BBI->mayWriteToMemory() || BBI == OtherBB->begin())
         return false;
     }
 
-    // In order to eliminate the store in OtherBr, we have to
-    // make sure nothing reads or overwrites the stored value in
-    // StoreBB.
+    // In order to eliminate the store in OtherBr, we have to make sure nothing
+    // reads or overwrites the stored value in StoreBB.
     for (BasicBlock::iterator I = StoreBB->begin(); &*I != &SI; ++I) {
       // FIXME: This should really be AA driven.
       if (I->mayReadFromMemory() || I->mayThrow() || I->mayWriteToMemory())
@@ -1618,24 +1599,24 @@ bool InstCombiner::SimplifyStoreAtEndOfBlock(StoreInst &SI) {
 
   // Insert a PHI node now if we need it.
   Value *MergedVal = OtherStore->getOperand(0);
+  // The debug locations of the original instructions might differ. Merge them.
+  DebugLoc MergedLoc = DILocation::getMergedLocation(SI.getDebugLoc(),
+                                                     OtherStore->getDebugLoc());
   if (MergedVal != SI.getOperand(0)) {
     PHINode *PN = PHINode::Create(MergedVal->getType(), 2, "storemerge");
     PN->addIncoming(SI.getOperand(0), SI.getParent());
     PN->addIncoming(OtherStore->getOperand(0), OtherBB);
     MergedVal = InsertNewInstBefore(PN, DestBB->front());
+    PN->setDebugLoc(MergedLoc);
   }
 
-  // Advance to a place where it is safe to insert the new store and
-  // insert it.
+  // Advance to a place where it is safe to insert the new store and insert it.
   BBI = DestBB->getFirstInsertionPt();
   StoreInst *NewSI = new StoreInst(MergedVal, SI.getOperand(1),
-                                   SI.isVolatile(),
-                                   SI.getAlignment(),
-                                   SI.getOrdering(),
-                                   SI.getSyncScopeID());
+                                   SI.isVolatile(), SI.getAlignment(),
+                                   SI.getOrdering(), SI.getSyncScopeID());
   InsertNewInstBefore(NewSI, *BBI);
-  // The debug locations of the original instructions might differ; merge them.
-  NewSI->applyMergedLocation(SI.getDebugLoc(), OtherStore->getDebugLoc());
+  NewSI->setDebugLoc(MergedLoc);
 
   // If the two stores had AA tags, merge them.
   AAMDNodes AATags;