[GVN] non-functional code movement

Summary: Move some code around, in preparation for later fixes
to the non-integral addrspace handling (D59661)

Patch By Jameson Nash <jameson@juliacomputing.com>

Reviewed By: reames, loladiro
Differential Revision: https://reviews.llvm.org/D59729

llvm-svn: 362853

2 files changed, 16 insertions, 16 deletions

diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
index a93a17f02e1..1ad051d669a 100644
--- a/llvm/lib/Transforms/Scalar/GVN.cpp
+++ b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -859,11 +859,12 @@ bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
 
   const DataLayout &DL = LI->getModule()->getDataLayout();
 
+  Instruction *DepInst = DepInfo.getInst();
   if (DepInfo.isClobber()) {
     // If the dependence is to a store that writes to a superset of the bits
     // read by the load, we can extract the bits we need for the load from the
     // stored value.
-    if (StoreInst *DepSI = dyn_cast<StoreInst>(DepInfo.getInst())) {
+    if (StoreInst *DepSI = dyn_cast<StoreInst>(DepInst)) {
       // Can't forward from non-atomic to atomic without violating memory model.
       if (Address && LI->isAtomic() <= DepSI->isAtomic()) {
         int Offset =
@@ -879,7 +880,7 @@ bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
     //    load i32* P
     //    load i8* (P+1)
     // if we have this, replace the later with an extraction from the former.
-    if (LoadInst *DepLI = dyn_cast<LoadInst>(DepInfo.getInst())) {
+    if (LoadInst *DepLI = dyn_cast<LoadInst>(DepInst)) {
       // If this is a clobber and L is the first instruction in its block, then
       // we have the first instruction in the entry block.
       // Can't forward from non-atomic to atomic without violating memory model.
@@ -896,7 +897,7 @@ bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
 
     // If the clobbering value is a memset/memcpy/memmove, see if we can
     // forward a value on from it.
-    if (MemIntrinsic *DepMI = dyn_cast<MemIntrinsic>(DepInfo.getInst())) {
+    if (MemIntrinsic *DepMI = dyn_cast<MemIntrinsic>(DepInst)) {
       if (Address && !LI->isAtomic()) {
         int Offset = analyzeLoadFromClobberingMemInst(LI->getType(), Address,
                                                       DepMI, DL);
@@ -910,8 +911,7 @@ bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
     LLVM_DEBUG(
         // fast print dep, using operator<< on instruction is too slow.
         dbgs() << "GVN: load "; LI->printAsOperand(dbgs());
-        Instruction *I = DepInfo.getInst();
-        dbgs() << " is clobbered by " << *I << '\n';);
+        dbgs() << " is clobbered by " << *DepInst << '\n';);
     if (ORE->allowExtraAnalysis(DEBUG_TYPE))
       reportMayClobberedLoad(LI, DepInfo, DT, ORE);
 
@@ -919,8 +919,6 @@ bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
   }
   assert(DepInfo.isDef() && "follows from above");
 
-  Instruction *DepInst = DepInfo.getInst();
-
   // Loading the allocation -> undef.
   if (isa<AllocaInst>(DepInst) || isMallocLikeFn(DepInst, TLI) ||
       // Loading immediately after lifetime begin -> undef.
@@ -939,9 +937,8 @@ bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
     // Reject loads and stores that are to the same address but are of
     // different types if we have to. If the stored value is larger or equal to
     // the loaded value, we can reuse it.
-    if (S->getValueOperand()->getType() != LI->getType() &&
-        !canCoerceMustAliasedValueToLoad(S->getValueOperand(),
-                                         LI->getType(), DL))
+    if (!canCoerceMustAliasedValueToLoad(S->getValueOperand(), LI->getType(),
+                                         DL))
       return false;
 
     // Can't forward from non-atomic to atomic without violating memory model.
@@ -956,8 +953,7 @@ bool GVN::AnalyzeLoadAvailability(LoadInst *LI, MemDepResult DepInfo,
     // If the types mismatch and we can't handle it, reject reuse of the load.
     // If the stored value is larger or equal to the loaded value, we can reuse
     // it.
-    if (LD->getType() != LI->getType() &&
-        !canCoerceMustAliasedValueToLoad(LD, LI->getType(), DL))
+    if (!canCoerceMustAliasedValueToLoad(LD, LI->getType(), DL))
       return false;
 
     // Can't forward from non-atomic to atomic without violating memory model.
diff --git a/llvm/lib/Transforms/Utils/VNCoercion.cpp b/llvm/lib/Transforms/Utils/VNCoercion.cpp
index 19593054c23..a77bf50fe10 100644
--- a/llvm/lib/Transforms/Utils/VNCoercion.cpp
+++ b/llvm/lib/Transforms/Utils/VNCoercion.cpp
@@ -14,13 +14,17 @@ namespace VNCoercion {
 /// Return true if coerceAvailableValueToLoadType will succeed.
 bool canCoerceMustAliasedValueToLoad(Value *StoredVal, Type *LoadTy,
                                      const DataLayout &DL) {
+  Type *StoredTy = StoredVal->getType();
+  if (StoredTy == LoadTy)
+    return true;
+
   // If the loaded or stored value is an first class array or struct, don't try
   // to transform them.  We need to be able to bitcast to integer.
-  if (LoadTy->isStructTy() || LoadTy->isArrayTy() ||
-      StoredVal->getType()->isStructTy() || StoredVal->getType()->isArrayTy())
+  if (LoadTy->isStructTy() || LoadTy->isArrayTy() || StoredTy->isStructTy() ||
+      StoredTy->isArrayTy())
     return false;
 
-  uint64_t StoreSize = DL.getTypeSizeInBits(StoredVal->getType());
+  uint64_t StoreSize = DL.getTypeSizeInBits(StoredTy);
 
   // The store size must be byte-aligned to support future type casts.
   if (llvm::alignTo(StoreSize, 8) != StoreSize)
@@ -306,7 +310,7 @@ int analyzeLoadFromClobberingMemInst(Type *LoadTy, Value *LoadPtr,
     return -1;
 
   GlobalVariable *GV = dyn_cast<GlobalVariable>(GetUnderlyingObject(Src, DL));
-  if (!GV || !GV->isConstant())
+  if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer())
     return -1;
 
   // See if the access is within the bounds of the transfer.