Introduce a helper to combine instruction metadata.

Replace the old code in GVN and BBVectorize with it. Update SimplifyCFG to use
it.

Patch by Björn Steinbrink!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215723 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h
index c0c690664a9c50330993d16093e598b5ddfc8570..81018598099851e772284eb7919a2f9935921e29 100644 (file)
--- a/include/llvm/Transforms/Utils/Local.h
+++ b/include/llvm/Transforms/Utils/Local.h
@@ -275,6 +275,11 @@ bool replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
 /// Returns true if any basic block was removed.
 bool removeUnreachableBlocks(Function &F);
 
+/// \brief Combine the metadata of two instructions so that K can replace J
+///
+/// Metadata not listed as known via KnownIDs is removed
+void combineMetadata(Instruction *K, const Instruction *J, ArrayRef<unsigned> KnownIDs);
+
 } // End llvm namespace
 
 #endif

diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 07be4955cb485a671ac0939066c5be8d1c178b31..a1fb7e9a65c346e85e6ee7ed48a2fc1ead3ad915 100644 (file)
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -45,6 +45,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Target/TargetLibraryInfo.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Transforms/Utils/SSAUpdater.h"
 #include <vector>
 using namespace llvm;
@@ -1776,49 +1777,24 @@ static void patchReplacementInstruction(Instruction *I, Value *Repl) {
       ReplOp->setHasNoUnsignedWrap(false);
   }
   if (Instruction *ReplInst = dyn_cast<Instruction>(Repl)) {
-    SmallVector<std::pair<unsigned, MDNode*>, 4> Metadata;
-    ReplInst->getAllMetadataOtherThanDebugLoc(Metadata);
-    for (int i = 0, n = Metadata.size(); i < n; ++i) {
-      unsigned Kind = Metadata[i].first;
-      MDNode *IMD = I->getMetadata(Kind);
-      MDNode *ReplMD = Metadata[i].second;
-      switch(Kind) {
-      default:
-        ReplInst->setMetadata(Kind, nullptr); // Remove unknown metadata
-        break;
-      case LLVMContext::MD_dbg:
-        llvm_unreachable("getAllMetadataOtherThanDebugLoc returned a MD_dbg");
-      case LLVMContext::MD_tbaa:
-        ReplInst->setMetadata(Kind, MDNode::getMostGenericTBAA(IMD, ReplMD));
-        break;
-      case LLVMContext::MD_alias_scope:
-      case LLVMContext::MD_noalias:
-        // FIXME: If both the original and replacement value are part of the
-        // same control-flow region (meaning that the execution of one
-        // guarentees the executation of the other), then we can combine the
-        // noalias scopes here and do better than the general conservative
-        // answer.
-
-        // In general, GVN unifies expressions over different control-flow
-        // regions, and so we need a conservative combination of the noalias
-        // scopes.
-        ReplInst->setMetadata(Kind, MDNode::intersect(IMD, ReplMD));
-        break;
-      case LLVMContext::MD_range:
-        ReplInst->setMetadata(Kind, MDNode::getMostGenericRange(IMD, ReplMD));
-        break;
-      case LLVMContext::MD_prof:
-        llvm_unreachable("MD_prof in a non-terminator instruction");
-        break;
-      case LLVMContext::MD_fpmath:
-        ReplInst->setMetadata(Kind, MDNode::getMostGenericFPMath(IMD, ReplMD));
-        break;
-      case LLVMContext::MD_invariant_load:
-        // Only set the !invariant.load if it is present in both instructions.
-        ReplInst->setMetadata(Kind, IMD);
-        break;
-      }
-    }
+    // FIXME: If both the original and replacement value are part of the
+    // same control-flow region (meaning that the execution of one
+    // guarentees the executation of the other), then we can combine the
+    // noalias scopes here and do better than the general conservative
+    // answer used in combineMetadata().
+
+    // In general, GVN unifies expressions over different control-flow
+    // regions, and so we need a conservative combination of the noalias
+    // scopes.
+    unsigned KnownIDs[] = {
+      LLVMContext::MD_tbaa,
+      LLVMContext::MD_alias_scope,
+      LLVMContext::MD_noalias,
+      LLVMContext::MD_range,
+      LLVMContext::MD_fpmath,
+      LLVMContext::MD_invariant_load,
+    };
+    combineMetadata(ReplInst, I, KnownIDs);
   }
 }
 

diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index d891fc0ee1cfee3df4b1b2ff304cadd58547ee5f..9b451449da958dbab494db41eb21c7f6597a73dc 100644 (file)
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -1305,3 +1305,39 @@ bool llvm::removeUnreachableBlocks(Function &F) {
 
   return true;
 }
+
+void llvm::combineMetadata(Instruction *K, const Instruction *J, ArrayRef<unsigned> KnownIDs) {
+  SmallVector<std::pair<unsigned, MDNode*>, 4> Metadata;
+  K->dropUnknownMetadata(KnownIDs);
+  K->getAllMetadataOtherThanDebugLoc(Metadata);
+  for (unsigned i = 0, n = Metadata.size(); i < n; ++i) {
+    unsigned Kind = Metadata[i].first;
+    MDNode *JMD = J->getMetadata(Kind);
+    MDNode *KMD = Metadata[i].second;
+
+    switch (Kind) {
+      default:
+        K->setMetadata(Kind, nullptr); // Remove unknown metadata
+        break;
+      case LLVMContext::MD_dbg:
+        llvm_unreachable("getAllMetadataOtherThanDebugLoc returned a MD_dbg");
+      case LLVMContext::MD_tbaa:
+        K->setMetadata(Kind, MDNode::getMostGenericTBAA(JMD, KMD));
+        break;
+      case LLVMContext::MD_alias_scope:
+      case LLVMContext::MD_noalias:
+        K->setMetadata(Kind, MDNode::intersect(JMD, KMD));
+        break;
+      case LLVMContext::MD_range:
+        K->setMetadata(Kind, MDNode::getMostGenericRange(JMD, KMD));
+        break;
+      case LLVMContext::MD_fpmath:
+        K->setMetadata(Kind, MDNode::getMostGenericFPMath(JMD, KMD));
+        break;
+      case LLVMContext::MD_invariant_load:
+        // Only set the !invariant.load if it is present in both instructions.
+        K->setMetadata(Kind, JMD);
+        break;
+    }
+  }
+}

diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index 63cb1c9abbfdf8a53f770db5f66adc5c643e4dca..cc3fbb19a6e60f6581dab6d7fb6fb3f0841bca66 100644 (file)
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -43,6 +43,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.h"
 #include <algorithm>
 #include <map>
 #include <set>
@@ -1040,6 +1041,13 @@ static bool HoistThenElseCodeToIf(BranchInst *BI, const DataLayout *DL) {
     if (!I2->use_empty())
       I2->replaceAllUsesWith(I1);
     I1->intersectOptionalDataWith(I2);
+    unsigned KnownIDs[] = {
+      LLVMContext::MD_tbaa,
+      LLVMContext::MD_range,
+      LLVMContext::MD_fpmath,
+      LLVMContext::MD_invariant_load
+    };
+    combineMetadata(I1, I2, KnownIDs);
     I2->eraseFromParent();
     Changed = true;
 

diff --git a/lib/Transforms/Vectorize/BBVectorize.cpp b/lib/Transforms/Vectorize/BBVectorize.cpp
index 9ee0ffb03bb98665c9792be019804eb560b51bf5..50c3fa41b1dad2136ba9ee0e78b23894d3cf9f6f 100644 (file)
--- a/lib/Transforms/Vectorize/BBVectorize.cpp
+++ b/lib/Transforms/Vectorize/BBVectorize.cpp
@@ -391,8 +391,6 @@ namespace {
                      Instruction *&InsertionPt,
                      Instruction *I, Instruction *J);
 
-    void combineMetadata(Instruction *K, const Instruction *J);
-
     bool vectorizeBB(BasicBlock &BB) {
       if (skipOptnoneFunction(BB))
         return false;
@@ -2964,35 +2962,6 @@ namespace {
     }
   }
 
-  // When the first instruction in each pair is cloned, it will inherit its
-  // parent's metadata. This metadata must be combined with that of the other
-  // instruction in a safe way.
-  void BBVectorize::combineMetadata(Instruction *K, const Instruction *J) {
-    SmallVector<std::pair<unsigned, MDNode*>, 4> Metadata;
-    K->getAllMetadataOtherThanDebugLoc(Metadata);
-    for (unsigned i = 0, n = Metadata.size(); i < n; ++i) {
-      unsigned Kind = Metadata[i].first;
-      MDNode *JMD = J->getMetadata(Kind);
-      MDNode *KMD = Metadata[i].second;
-
-      switch (Kind) {
-      default:
-        K->setMetadata(Kind, nullptr); // Remove unknown metadata
-        break;
-      case LLVMContext::MD_tbaa:
-        K->setMetadata(Kind, MDNode::getMostGenericTBAA(JMD, KMD));
-        break;
-      case LLVMContext::MD_alias_scope:
-      case LLVMContext::MD_noalias:
-        K->setMetadata(Kind, MDNode::intersect(JMD, KMD));
-        break;
-      case LLVMContext::MD_fpmath:
-        K->setMetadata(Kind, MDNode::getMostGenericFPMath(JMD, KMD));
-        break;
-      }
-    }
-  }
-
   // This function fuses the chosen instruction pairs into vector instructions,
   // taking care preserve any needed scalar outputs and, then, it reorders the
   // remaining instructions as needed (users of the first member of the pair
@@ -3142,7 +3111,13 @@ namespace {
       if (!isa<StoreInst>(K))
         K->mutateType(getVecTypeForPair(L->getType(), H->getType()));
 
-      combineMetadata(K, H);
+      unsigned KnownIDs[] = {
+        LLVMContext::MD_tbaa,
+        LLVMContext::MD_alias_scope,
+        LLVMContext::MD_noalias,
+        LLVMContext::MD_fpmath
+      };
+      combineMetadata(K, H, KnownIDs);
       K->intersectOptionalDataWith(H);
 
       for (unsigned o = 0; o < NumOperands; ++o)