3 files changed, 22 insertions, 30 deletions

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index b3905cc01e84..ed328f12c463 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -127,10 +127,15 @@ static cl::opt<unsigned> MulOpsInlineThreshold(
     cl::desc("Threshold for inlining multiplication operands into a SCEV"),
     cl::init(1000));
 
-static cl::opt<unsigned>
-    MaxCompareDepth("scalar-evolution-max-compare-depth", cl::Hidden,
-                    cl::desc("Maximum depth of recursive compare complexity"),
-                    cl::init(32));
+static cl::opt<unsigned> MaxSCEVCompareDepth(
+    "scalar-evolution-max-scev-compare-depth", cl::Hidden,
+    cl::desc("Maximum depth of recursive SCEV complexity comparisons"),
+    cl::init(32));
+
+static cl::opt<unsigned> MaxValueCompareDepth(
+    "scalar-evolution-max-value-compare-depth", cl::Hidden,
+    cl::desc("Maximum depth of recursive value complexity comparisons"),
+    cl::init(2));
 
 //===----------------------------------------------------------------------===//
 //                           SCEV class definitions
@@ -481,7 +486,7 @@ static int
 CompareValueComplexity(SmallSet<std::pair<Value *, Value *>, 8> &EqCache,
                        const LoopInfo *const LI, Value *LV, Value *RV,
                        unsigned Depth) {
-  if (Depth > MaxCompareDepth || EqCache.count({LV, RV}))
+  if (Depth > MaxValueCompareDepth || EqCache.count({LV, RV}))
     return 0;
 
   // Order pointer values after integer values. This helps SCEVExpander form
@@ -568,7 +573,7 @@ static int CompareSCEVComplexity(
   if (LType != RType)
     return (int)LType - (int)RType;
 
-  if (Depth > MaxCompareDepth || EqCacheSCEV.count({LHS, RHS}))
+  if (Depth > MaxSCEVCompareDepth || EqCacheSCEV.count({LHS, RHS}))
     return 0;
   // Aside from the getSCEVType() ordering, the particular ordering
   // isn't very important except that it's beneficial to be consistent,
diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index d086ee05a64f..941efb210d1c 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -141,8 +141,8 @@ static cl::opt<int> PreInlineThreshold(
              "(default = 75)"));
 
 static cl::opt<bool> EnableGVNHoist(
-    "enable-gvn-hoist", cl::init(true), cl::Hidden,
-    cl::desc("Enable the GVN hoisting pass (default = on)"));
+    "enable-gvn-hoist", cl::init(false), cl::Hidden,
+    cl::desc("Enable the GVN hoisting pass"));
 
 static cl::opt<bool>
     DisableLibCallsShrinkWrap("disable-libcalls-shrinkwrap", cl::init(false),
diff --git a/lib/Transforms/Scalar/GVNHoist.cpp b/lib/Transforms/Scalar/GVNHoist.cpp
index 90c26e13db78..f8e1d2e1a08a 100644
--- a/lib/Transforms/Scalar/GVNHoist.cpp
+++ b/lib/Transforms/Scalar/GVNHoist.cpp
@@ -200,13 +200,11 @@ static void combineKnownMetadata(Instruction *ReplInst, Instruction *I) {
 class GVNHoist {
 public:
   GVNHoist(DominatorTree *DT, AliasAnalysis *AA, MemoryDependenceResults *MD,
-           MemorySSA *MSSA, bool OptForMinSize)
-      : DT(DT), AA(AA), MD(MD), MSSA(MSSA), OptForMinSize(OptForMinSize),
-        HoistingGeps(OptForMinSize), HoistedCtr(0) {
-      // Hoist as far as possible when optimizing for code-size.
-      if (OptForMinSize)
-        MaxNumberOfBBSInPath = -1;
-  }
+           MemorySSA *MSSA)
+      : DT(DT), AA(AA), MD(MD), MSSA(MSSA),
+        HoistingGeps(false),
+        HoistedCtr(0)
+  { }
 
   bool run(Function &F) {
     VN.setDomTree(DT);
@@ -251,7 +249,6 @@ private:
   AliasAnalysis *AA;
   MemoryDependenceResults *MD;
   MemorySSA *MSSA;
-  const bool OptForMinSize;
   const bool HoistingGeps;
   DenseMap<const Value *, unsigned> DFSNumber;
   BBSideEffectsSet BBSideEffects;
@@ -505,11 +502,6 @@ private:
   bool safeToHoistScalar(const BasicBlock *HoistBB,
                          SmallPtrSetImpl<const BasicBlock *> &WL,
                          int &NBBsOnAllPaths) {
-    // Enable scalar hoisting at -Oz as it is safe to hoist scalars to a place
-    // where they are partially needed.
-    if (OptForMinSize)
-      return true;
-
     // Check that the hoisted expression is needed on all paths.
     if (!hoistingFromAllPaths(HoistBB, WL))
       return false;
@@ -923,13 +915,8 @@ private:
                 Intr->getIntrinsicID() == Intrinsic::assume)
               continue;
           }
-          if (Call->mayHaveSideEffects()) {
-            if (!OptForMinSize)
-              break;
-            // We may continue hoisting across calls which write to memory.
-            if (Call->mayThrow())
-              break;
-          }
+          if (Call->mayHaveSideEffects())
+            break;
 
           if (Call->isConvergent())
             break;
@@ -971,7 +958,7 @@ public:
     auto &MD = getAnalysis<MemoryDependenceWrapperPass>().getMemDep();
     auto &MSSA = getAnalysis<MemorySSAWrapperPass>().getMSSA();
 
-    GVNHoist G(&DT, &AA, &MD, &MSSA, F.optForMinSize());
+    GVNHoist G(&DT, &AA, &MD, &MSSA);
     return G.run(F);
   }
 
@@ -991,7 +978,7 @@ PreservedAnalyses GVNHoistPass::run(Function &F, FunctionAnalysisManager &AM) {
   AliasAnalysis &AA = AM.getResult<AAManager>(F);
   MemoryDependenceResults &MD = AM.getResult<MemoryDependenceAnalysis>(F);
   MemorySSA &MSSA = AM.getResult<MemorySSAAnalysis>(F).getMSSA();
-  GVNHoist G(&DT, &AA, &MD, &MSSA, F.optForMinSize());
+  GVNHoist G(&DT, &AA, &MD, &MSSA);
   if (!G.run(F))
     return PreservedAnalyses::all();