diff --git a/llvm/include/llvm/Analysis/MemoryDependenceAnalysis.h b/llvm/include/llvm/Analysis/MemoryDependenceAnalysis.h
--- a/llvm/include/llvm/Analysis/MemoryDependenceAnalysis.h
+++ b/llvm/include/llvm/Analysis/MemoryDependenceAnalysis.h
@@ -363,6 +363,7 @@
   PredIteratorCache PredCache;
 
   unsigned DefaultBlockScanLimit;
+  Optional<int32_t> ClobberOffset;
 
 public:
   MemoryDependenceResults(AAResults &AA, AssumptionCache &AC,
@@ -468,6 +469,8 @@
   /// Release memory in caches.
   void releaseMemory();
 
+  Optional<int32_t> getClobberOffset() const { return ClobberOffset; }
+
 private:
   MemDepResult getCallDependencyFrom(CallBase *Call, bool isReadOnlyCall,
                                      BasicBlock::iterator ScanIt,
diff --git a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
--- a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -512,16 +512,12 @@
         if (R == AliasResult::MustAlias)
           return MemDepResult::getDef(Inst);
 
-#if 0 // FIXME: Temporarily disabled. GVN is cleverly rewriting loads
-      // in terms of clobbering loads, but since it does this by looking
-      // at the clobbering load directly, it doesn't know about any
-      // phi translation that may have happened along the way.
-
         // If we have a partial alias, then return this as a clobber for the
         // client to handle.
-        if (R == AliasResult::PartialAlias)
+        if (R == AliasResult::PartialAlias && R.hasOffset()) {
+          ClobberOffset = R.getOffset();
           return MemDepResult::getClobber(Inst);
-#endif
+        }
 
         // Random may-alias loads don't depend on each other without a
         // dependence.
@@ -640,6 +636,7 @@
 }
 
 MemDepResult MemoryDependenceResults::getDependency(Instruction *QueryInst) {
+  ClobberOffset = None;
   Instruction *ScanPos = QueryInst;
 
   // Check for a cached result
diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
--- a/llvm/lib/Transforms/Scalar/GVN.cpp
+++ b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -998,9 +998,22 @@
       // Can't forward from non-atomic to atomic without violating memory model.
       if (DepLoad != Load && Address &&
           Load->isAtomic() <= DepLoad->isAtomic()) {
-        int Offset = analyzeLoadFromClobberingLoad(Load->getType(), Address,
-                                                   DepLoad, DL);
-
+        Type *LoadType = Load->getType();
+        int Offset = -1;
+
+        // If Memory Dependence Analysis reported clobber check, it was nested
+        // and can be extracted from the MD result
+        if (DepInfo.isClobber() &&
+            canCoerceMustAliasedValueToLoad(DepLoad, LoadType, DL)) {
+          const auto ClobberOff = MD->getClobberOffset();
+          // TODO: GVN has no deal with a negative offset.
+          Offset = (ClobberOff == None || ClobberOff.getValue() < 0)
+                       ? -1
+                       : ClobberOff.getValue();
+        }
+        if (Offset == -1)
+          Offset =
+              analyzeLoadFromClobberingLoad(LoadType, Address, DepLoad, DL);
         if (Offset != -1) {
           Res = AvailableValue::getLoad(DepLoad, Offset);
           return true;
diff --git a/llvm/test/Transforms/GVN/PRE/rle.ll b/llvm/test/Transforms/GVN/PRE/rle.ll
--- a/llvm/test/Transforms/GVN/PRE/rle.ll
+++ b/llvm/test/Transforms/GVN/PRE/rle.ll
@@ -699,14 +699,14 @@
   %add = add nsw i32 %tmp2, %conv
   ret i32 %add
 
-; TEMPORARILYDISABLED-LABEL: @load_load_partial_alias(
-; TEMPORARILYDISABLED: load i32, i32*
-; TEMPORARILYDISABLED-NOT: load
-; TEMPORARILYDISABLED: lshr i32 {{.*}}, 8
-; TEMPORARILYDISABLED-NOT: load
-; TEMPORARILYDISABLED: trunc i32 {{.*}} to i8
-; TEMPORARILYDISABLED-NOT: load
-; TEMPORARILYDISABLED: ret i32
+; CHECK-LABEL: @load_load_partial_alias(
+; CHECK: load i32, i32*
+; CHECK-NOT: load
+; CHECK: lshr i32 {{.*}}, {{8|16}}
+; CHECK-NOT: load
+; CHECK: trunc i32 {{.*}} to i8
+; CHECK-NOT: load
+; CHECK: ret i32
 }
 
 
@@ -726,12 +726,36 @@
 
 if.end:
   ret i32 52
-; TEMPORARILY_DISABLED-LABEL: @load_load_partial_alias_cross_block(
-; TEMPORARILY_DISABLED: land.lhs.true:
-; TEMPORARILY_DISABLED-NOT: load i8
-; TEMPORARILY_DISABLED: ret i32 %conv6
+; CHECK-LABEL: @load_load_partial_alias_cross_block(
+; CHECK: land.lhs.true:
+; CHECK-NOT: load i8
+; CHECK: ret i32 %conv6
 }
 
+; Cross block partial alias case with phi translation.
+; FIXME: Currently we fail to clobber both partially aliased cases of load.
+define i32 @load_load_partial_alias_cross_block_phi_trans(i8* %P) nounwind ssp {
+entry:
+  %xx = bitcast i8* %P to i32*
+  %x1 = load i32, i32* %xx, align 4
+  %cmp = icmp eq i32 %x1, 127
+  br i1 %cmp, label %inc, label %end
+
+inc:
+  br label %end
+
+end:
+  %ind = phi i64 [1, %entry], [2, %inc]
+  %arrayidx4 = getelementptr inbounds i8, i8* %P, i64 %ind
+  %tmp5 = load i8, i8* %arrayidx4, align 1
+  %conv6 = zext i8 %tmp5 to i32
+  ret i32 %conv6
+
+; CHECK-LABEL: @load_load_partial_alias_cross_block_phi_trans(
+; CHECK: end:
+; CHECK: load i8
+; CHECK: ret i32 %conv6
+}
 
 ;;===----------------------------------------------------------------------===;;
 ;; Load Widening