[Local] Make DoesKMove required for combineMetadata.

This patch makes the DoesKMove argument non-optional, to force people
to think about it. Most cases where it is false are either code hoisting
or code sinking, where we pick one instruction from a set of
equal instructions among different code paths.

Reviewers: dberlin, nlopes, efriedma, davide

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D47475

llvm-svn: 340606

8 files changed, 12 insertions, 11 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
index 5f0931ead49..1ff7037c8d2 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineLoadStoreAlloca.cpp
@@ -1026,7 +1026,7 @@ 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(),
diff --git a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
index e54a1dd05a2..911ece347d3 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
@@ -616,7 +616,7 @@ Instruction *InstCombiner::FoldPHIArgLoadIntoPHI(PHINode &PN) {
   // Add all operands to the new PHI and combine TBAA metadata.
   for (unsigned i = 1, e = PN.getNumIncomingValues(); i != e; ++i) {
     LoadInst *LI = cast<LoadInst>(PN.getIncomingValue(i));
-    combineMetadata(NewLI, LI, KnownIDs);
+    combineMetadata(NewLI, LI, KnownIDs, true);
     Value *NewInVal = LI->getOperand(0);
     if (NewInVal != InVal)
       InVal = nullptr;
diff --git a/llvm/lib/Transforms/Scalar/GVNHoist.cpp b/llvm/lib/Transforms/Scalar/GVNHoist.cpp
index 6d2b25cf601..00409ac035d 100644
--- a/llvm/lib/Transforms/Scalar/GVNHoist.cpp
+++ b/llvm/lib/Transforms/Scalar/GVNHoist.cpp
@@ -247,7 +247,7 @@ static void combineKnownMetadata(Instruction *ReplInst, Instruction *I) {
       LLVMContext::MD_noalias,        LLVMContext::MD_range,
       LLVMContext::MD_fpmath,         LLVMContext::MD_invariant_load,
       LLVMContext::MD_invariant_group};
-  combineMetadata(ReplInst, I, KnownIDs);
+  combineMetadata(ReplInst, I, KnownIDs, true);
 }
 
 // This pass hoists common computations across branches sharing common
diff --git a/llvm/lib/Transforms/Scalar/GVNSink.cpp b/llvm/lib/Transforms/Scalar/GVNSink.cpp
index 8959038de59..3737831e59b 100644
--- a/llvm/lib/Transforms/Scalar/GVNSink.cpp
+++ b/llvm/lib/Transforms/Scalar/GVNSink.cpp
@@ -859,7 +859,7 @@ void GVNSink::sinkLastInstruction(ArrayRef<BasicBlock *> Blocks,
   // Update metadata and IR flags.
   for (auto *I : Insts)
     if (I != I0) {
-      combineMetadataForCSE(I0, I);
+      combineMetadataForCSE(I0, I, true);
       I0->andIRFlags(I);
     }
 
diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index 7b738fd5086..45e73e98b4c 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -1300,7 +1300,7 @@ bool JumpThreadingPass::SimplifyPartiallyRedundantLoad(LoadInst *LoadI) {
 
     if (IsLoadCSE) {
       LoadInst *NLoadI = cast<LoadInst>(AvailableVal);
-      combineMetadataForCSE(NLoadI, LoadI);
+      combineMetadataForCSE(NLoadI, LoadI, false);
     };
 
     // If the returned value is the load itself, replace with an undef. This can
@@ -1490,7 +1490,7 @@ bool JumpThreadingPass::SimplifyPartiallyRedundantLoad(LoadInst *LoadI) {
   }
 
   for (LoadInst *PredLoadI : CSELoads) {
-    combineMetadataForCSE(PredLoadI, LoadI);
+    combineMetadataForCSE(PredLoadI, LoadI, true);
   }
 
   LoadI->replaceAllUsesWith(PN);
diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 3b74421a47a..0e430eab6b2 100644
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -994,7 +994,7 @@ bool MemCpyOptPass::performCallSlotOptzn(Instruction *cpy, Value *cpyDest,
   unsigned KnownIDs[] = {LLVMContext::MD_tbaa, LLVMContext::MD_alias_scope,
                          LLVMContext::MD_noalias,
                          LLVMContext::MD_invariant_group};
-  combineMetadata(C, cpy, KnownIDs);
+  combineMetadata(C, cpy, KnownIDs, true);
 
   // Remove the memcpy.
   MD->removeInstruction(cpy);
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index b8aa21be5c5..5ac66742c7c 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -2354,7 +2354,8 @@ void llvm::combineMetadata(Instruction *K, const Instruction *J,
       K->setMetadata(LLVMContext::MD_invariant_group, JMD);
 }
 
-void llvm::combineMetadataForCSE(Instruction *K, const Instruction *J) {
+void llvm::combineMetadataForCSE(Instruction *K, const Instruction *J,
+                                 bool KDominatesJ) {
   unsigned KnownIDs[] = {
       LLVMContext::MD_tbaa,            LLVMContext::MD_alias_scope,
       LLVMContext::MD_noalias,         LLVMContext::MD_range,
@@ -2362,7 +2363,7 @@ void llvm::combineMetadataForCSE(Instruction *K, const Instruction *J) {
       LLVMContext::MD_invariant_group, LLVMContext::MD_align,
       LLVMContext::MD_dereferenceable,
       LLVMContext::MD_dereferenceable_or_null};
-  combineMetadata(K, J, KnownIDs);
+  combineMetadata(K, J, KnownIDs, KDominatesJ);
 }
 
 void llvm::patchReplacementInstruction(Instruction *I, Value *Repl) {
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 4dbecf97794..28ed77adb18 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1316,7 +1316,7 @@ static bool HoistThenElseCodeToIf(BranchInst *BI,
                              LLVMContext::MD_dereferenceable,
                              LLVMContext::MD_dereferenceable_or_null,
                              LLVMContext::MD_mem_parallel_loop_access};
-      combineMetadata(I1, I2, KnownIDs);
+      combineMetadata(I1, I2, KnownIDs, true);
 
       // I1 and I2 are being combined into a single instruction.  Its debug
       // location is the merged locations of the original instructions.
@@ -1582,7 +1582,7 @@ static bool sinkLastInstruction(ArrayRef<BasicBlock*> Blocks) {
       // However, as N-way merge for CallInst is rare, so we use simplified API
       // instead of using complex API for N-way merge.
       I0->applyMergedLocation(I0->getDebugLoc(), I->getDebugLoc());
-      combineMetadataForCSE(I0, I);
+      combineMetadataForCSE(I0, I, true);
       I0->andIRFlags(I);
     }