vendor/llvm/llvm-release_70-r348011

4 files changed, 26 insertions, 4 deletions

diff --git a/include/llvm/MC/MCAsmBackend.h b/include/llvm/MC/MCAsmBackend.h
index 030d3c05aa5ad..07835c21fcedb 100644
--- a/include/llvm/MC/MCAsmBackend.h
+++ b/include/llvm/MC/MCAsmBackend.h
@@ -165,6 +165,11 @@ public:
     return 0;
   }
 
+  /// Check whether a given symbol has been flagged with MICROMIPS flag.
+  virtual bool isMicroMips(const MCSymbol *Sym) const {
+    return false;
+  }
+
   /// Handles all target related code padding when starting to write a new
   /// basic block to an object file.
   ///
diff --git a/include/llvm/Support/GenericDomTreeConstruction.h b/include/llvm/Support/GenericDomTreeConstruction.h
index 103ff8ca476a9..977f209f92b39 100644
--- a/include/llvm/Support/GenericDomTreeConstruction.h
+++ b/include/llvm/Support/GenericDomTreeConstruction.h
@@ -1186,6 +1186,20 @@ struct SemiNCAInfo {
                << '\t' << U << "\n");
     LLVM_DEBUG(dbgs() << "\n");
 
+    // Recalculate the DominatorTree when the number of updates
+    // exceeds a threshold, which usually makes direct updating slower than
+    // recalculation. We select this threshold proportional to the
+    // size of the DominatorTree. The constant is selected
+    // by choosing the one with an acceptable performance on some real-world
+    // inputs.
+
+    // Make unittests of the incremental algorithm work
+    if (DT.DomTreeNodes.size() <= 100) {
+      if (NumLegalized > DT.DomTreeNodes.size())
+        CalculateFromScratch(DT, &BUI);
+    } else if (NumLegalized > DT.DomTreeNodes.size() / 40)
+      CalculateFromScratch(DT, &BUI);
+
     // If the DominatorTree was recalculated at some point, stop the batch
     // updates. Full recalculations ignore batch updates and look at the actual
     // CFG.
diff --git a/include/llvm/Transforms/Utils/SSAUpdater.h b/include/llvm/Transforms/Utils/SSAUpdater.h
index 4a79116629902..d02607acbbb57 100644
--- a/include/llvm/Transforms/Utils/SSAUpdater.h
+++ b/include/llvm/Transforms/Utils/SSAUpdater.h
@@ -76,6 +76,10 @@ public:
   /// block.
   bool HasValueForBlock(BasicBlock *BB) const;
 
+  /// Return the value for the specified block if the SSAUpdater has one,
+  /// otherwise return nullptr.
+  Value *FindValueForBlock(BasicBlock *BB) const;
+
   /// Construct SSA form, materializing a value that is live at the end
   /// of the specified block.
   Value *GetValueAtEndOfBlock(BasicBlock *BB);
diff --git a/include/llvm/Transforms/Utils/SSAUpdaterImpl.h b/include/llvm/Transforms/Utils/SSAUpdaterImpl.h
index b7649ba883344..cab0f3e715757 100644
--- a/include/llvm/Transforms/Utils/SSAUpdaterImpl.h
+++ b/include/llvm/Transforms/Utils/SSAUpdaterImpl.h
@@ -357,10 +357,9 @@ public:
       BBInfo *Info = *I;
 
       if (Info->DefBB != Info) {
-        // Record the available value at join nodes to speed up subsequent
-        // uses of this SSAUpdater for the same value.
-        if (Info->NumPreds > 1)
-          (*AvailableVals)[Info->BB] = Info->DefBB->AvailableVal;
+        // Record the available value to speed up subsequent uses of this
+        // SSAUpdater for the same value.
+        (*AvailableVals)[Info->BB] = Info->DefBB->AvailableVal;
         continue;
       }