diff --git a/llvm/lib/Transforms/Scalar/NewGVN.cpp b/llvm/lib/Transforms/Scalar/NewGVN.cpp
--- a/llvm/lib/Transforms/Scalar/NewGVN.cpp
+++ b/llvm/lib/Transforms/Scalar/NewGVN.cpp
@@ -2624,14 +2624,42 @@
     }
 
     auto *OrigI = cast<Instruction>(I);
-    // When we hit an instruction that reads memory (load, call, etc), we must
-    // consider any store that may happen in the loop. For now, we assume the
-    // worst: there is a store in the loop that alias with this read.
-    // The case where the load is outside the loop is already covered by the
-    // dominator check above.
-    // TODO: relax this condition
-    if (OrigI->mayReadFromMemory())
-      return false;
+    
+    if (MemoryAccess *OriginalAccess = getMemoryAccess(OrigI)) {
+      SmallVector<MemoryAccess *, 4> MemAccessWorkList;
+      MemAccessWorkList.push_back(
+          MSSAWalker->getClobberingMemoryAccess(OriginalAccess));
+
+      // We only want memory defs/phis that might alias with the original
+      // access, so if we can, pass the location to the walker.
+      MemoryLocation Loc =
+          MemoryLocation::getOrNone(OrigI).value_or(MemoryLocation());
+      while (!MemAccessWorkList.empty()) {
+        auto *MemAccess = MemAccessWorkList.pop_back_val();
+        if (MSSA->isLiveOnEntryDef(MemAccess))
+          continue;
+
+        // Phi block is dominated - safe.
+        if (DT->properlyDominates(MemAccess->getBlock(), PHIBlock)) {
+          OpSafeForPHIOfOps.insert({I, true});
+          continue;
+        }
+
+        // Clobbering MemoryPhi - unsafe.
+        // Note : Only checking memory phis allows us to skip redundant stores
+        if (isa<MemoryPhi>(MemAccess) &&
+            MemAccess ==
+                MSSAWalker->getClobberingMemoryAccess(MemAccess, Loc)) {
+          OpSafeForPHIOfOps.insert({I, false});
+          return false;
+        }
+
+        // Add potential clobber of the original access.
+        MemAccessWorkList.push_back(MSSAWalker->getClobberingMemoryAccess(
+            cast<MemoryUseOrDef>(MemAccess)));
+        continue;
+      }
+    }
 
     // Check the operands of the current instruction.
     for (auto *Op : OrigI->operand_values()) {
diff --git a/llvm/test/Transforms/NewGVN/phi-of-ops-loads.ll b/llvm/test/Transforms/NewGVN/phi-of-ops-loads.ll
--- a/llvm/test/Transforms/NewGVN/phi-of-ops-loads.ll
+++ b/llvm/test/Transforms/NewGVN/phi-of-ops-loads.ll
@@ -77,18 +77,55 @@
   ret void
 }
 
-; TODO: we should support this case
-define void @no-alias-store-in-loop(ptr noalias %p, ptr noalias %q) {
-; CHECK-LABEL: @no-alias-store-in-loop(
+define void @clobber-in-loop2(ptr %p, ptr %q, i1 %a) {
+; CHECK-LABEL: @clobber-in-loop2(
 ; CHECK-NEXT:  bb56:
 ; CHECK-NEXT:    br label [[BB57:%.*]]
 ; CHECK:       bb57:
 ; CHECK-NEXT:    [[N59:%.*]] = phi i1 [ false, [[BB229:%.*]] ], [ true, [[BB56:%.*]] ]
 ; CHECK-NEXT:    [[IDX:%.*]] = phi i8 [ 0, [[BB56]] ], [ [[INC:%.*]], [[BB229]] ]
+; CHECK-NEXT:    call void @f()
+; CHECK-NEXT:    br i1 [[A:%.*]], label [[BB229]], label [[BB237:%.*]]
+; CHECK:       bb229:
 ; CHECK-NEXT:    [[N60:%.*]] = load i8, ptr [[P:%.*]], align 1
 ; CHECK-NEXT:    [[N62:%.*]] = icmp ne i8 [[N60]], 2
 ; CHECK-NEXT:    [[N63:%.*]] = or i1 [[N59]], [[N62]]
-; CHECK-NEXT:    br i1 [[N63]], label [[BB229]], label [[BB237:%.*]]
+; CHECK-NEXT:    [[INC]] = add i8 [[IDX]], 1
+; CHECK-NEXT:    br i1 [[N63]], label [[BB57]], label [[BB237]]
+; CHECK:       bb237:
+; CHECK-NEXT:    ret void
+;
+bb56:
+  br label %bb57
+
+bb57:
+  %n59 = phi i1 [ false, %bb229 ], [ true, %bb56 ]
+  %idx = phi i8 [0, %bb56], [%inc, %bb229]
+  call void @f()
+  br i1 %a, label %bb229, label %bb237
+
+bb229:
+  %n60 = load i8, ptr %p
+  %n62 = icmp ne i8 %n60, 2
+  %n63 = or i1 %n59, %n62
+  %inc = add i8 %idx, 1
+  br i1 %n63, label %bb57, label %bb237
+
+bb237:
+  ret void
+}
+
+define void @no-alias-store-in-loop(ptr noalias %p, ptr noalias %q) {
+; CHECK-LABEL: @no-alias-store-in-loop(
+; CHECK-NEXT:  bb56:
+; CHECK-NEXT:    br label [[BB57:%.*]]
+; CHECK:       bb57:
+; CHECK-NEXT:    [[PHIOFOPS:%.*]] = phi i1 [ true, [[BB56:%.*]] ], [ [[N62:%.*]], [[BB229:%.*]] ]
+; CHECK-NEXT:    [[N59:%.*]] = phi i1 [ false, [[BB229]] ], [ true, [[BB56]] ]
+; CHECK-NEXT:    [[IDX:%.*]] = phi i8 [ 0, [[BB56]] ], [ [[INC:%.*]], [[BB229]] ]
+; CHECK-NEXT:    [[N60:%.*]] = load i8, ptr [[P:%.*]], align 1
+; CHECK-NEXT:    [[N62]] = icmp ne i8 [[N60]], 2
+; CHECK-NEXT:    br i1 [[PHIOFOPS]], label [[BB229]], label [[BB237:%.*]]
 ; CHECK:       bb229:
 ; CHECK-NEXT:    [[INC]] = add i8 [[IDX]], 1
 ; CHECK-NEXT:    store i8 [[INC]], ptr [[Q:%.*]], align 1
@@ -150,17 +187,16 @@
   ret void
 }
 
-; TODO: we should support this case
 define void @nowrite-function-in-loop(ptr %p) {
 ; CHECK-LABEL: @nowrite-function-in-loop(
 ; CHECK-NEXT:  bb56:
 ; CHECK-NEXT:    br label [[BB57:%.*]]
 ; CHECK:       bb57:
-; CHECK-NEXT:    [[N59:%.*]] = phi i1 [ false, [[BB229:%.*]] ], [ true, [[BB56:%.*]] ]
+; CHECK-NEXT:    [[PHIOFOPS:%.*]] = phi i1 [ true, [[BB56:%.*]] ], [ [[N62:%.*]], [[BB229:%.*]] ]
+; CHECK-NEXT:    [[N59:%.*]] = phi i1 [ false, [[BB229]] ], [ true, [[BB56]] ]
 ; CHECK-NEXT:    [[N60:%.*]] = load i8, ptr [[P:%.*]], align 1
-; CHECK-NEXT:    [[N62:%.*]] = icmp ne i8 [[N60]], 2
-; CHECK-NEXT:    [[N63:%.*]] = or i1 [[N59]], [[N62]]
-; CHECK-NEXT:    br i1 [[N63]], label [[BB229]], label [[BB237:%.*]]
+; CHECK-NEXT:    [[N62]] = icmp ne i8 [[N60]], 2
+; CHECK-NEXT:    br i1 [[PHIOFOPS]], label [[BB229]], label [[BB237:%.*]]
 ; CHECK:       bb229:
 ; CHECK-NEXT:    call void @f() #[[ATTR0:[0-9]+]]
 ; CHECK-NEXT:    br label [[BB57]]
@@ -199,9 +235,7 @@
 ; CHECK-NEXT:    [[PHI1:%.*]] = phi i8 [ [[LD1]], [[COND_TRUE]] ], [ 0, [[FOR_BODY:%.*]] ]
 ; CHECK-NEXT:    [[ARRAYIDX42:%.*]] = getelementptr inbounds [3 x [2 x [1 x i8]]], ptr [[ARRAY]], i64 109, i64 0, i64 0, i64 undef
 ; CHECK-NEXT:    [[LD2:%.*]] = load i8, ptr [[ARRAYIDX42]], align 1
-; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult i8 [[LD2]], [[PHI1]]
-; CHECK-NEXT:    [[ZEXT:%.*]] = zext i1 [[CMP1]] to i32
-; CHECK-NEXT:    store i32 [[ZEXT]], ptr [[P2:%.*]], align 4
+; CHECK-NEXT:    store i32 0, ptr [[P2:%.*]], align 4
 ; CHECK-NEXT:    br i1 [[COND2:%.*]], label [[COND_END:%.*]], label [[EXIT:%.*]]
 ; CHECK:       cond.end:
 ; CHECK-NEXT:    [[LD3:%.*]] = load i16, ptr [[P1:%.*]], align 2
@@ -243,3 +277,58 @@
   store i32 %sel, ptr %p3, align 4
   ret void
 }
+
+define void @function-in-branch-in-loop(ptr %p, i8 %a, i8 %x) {
+; CHECK-LABEL: @function-in-branch-in-loop(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[WHILE:%.*]]
+; CHECK:       while:
+; CHECK-NEXT:    [[PHI:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ false, [[BODY2:%.*]] ]
+; CHECK-NEXT:    [[I:%.*]] = phi i8 [ 0, [[ENTRY]] ], [ [[I2:%.*]], [[BODY2]] ]
+; CHECK-NEXT:    [[WHILE_COND:%.*]] = icmp ule i8 [[I]], [[X:%.*]]
+; CHECK-NEXT:    br i1 [[WHILE_COND]], label [[BODY:%.*]], label [[EXIT:%.*]]
+; CHECK:       body:
+; CHECK-NEXT:    [[IF_COND:%.*]] = icmp sgt i8 [[A:%.*]], 0
+; CHECK-NEXT:    br i1 [[IF_COND]], label [[IF_THEN:%.*]], label [[IF_ELSE:%.*]]
+; CHECK:       if.then:
+; CHECK-NEXT:    call void @f()
+; CHECK-NEXT:    br label [[BODY2]]
+; CHECK:       if.else:
+; CHECK-NEXT:    br label [[BODY2]]
+; CHECK:       body2:
+; CHECK-NEXT:    [[I2]] = add i8 [[I]], 1
+; CHECK-NEXT:    [[LD:%.*]] = load i1, ptr [[P:%.*]], align 1
+; CHECK-NEXT:    [[OR:%.*]] = or i1 [[PHI]], [[LD]]
+; CHECK-NEXT:    br i1 [[OR]], label [[WHILE]], label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %while
+
+while:
+  %phi = phi i1 [ true, %entry ], [ false, %body2 ]
+  %i = phi i8 [ 0, %entry ], [ %i2, %body2 ]
+  %while.cond = icmp ule i8 %i, %x
+  br i1 %while.cond, label %body, label %exit
+
+body:
+  %if.cond = icmp sgt i8 %a, 0
+  br i1 %if.cond, label %if.then, label %if.else
+
+if.then:
+  call void @f()
+  br label %body2
+
+if.else:
+  br label %body2
+
+body2:
+  %i2 = add i8 %i, 1
+  %ld = load i1, ptr %p
+  %or = or i1 %phi, %ld
+  br i1 %or, label %while, label %exit
+
+exit:
+  ret void
+}
diff --git a/llvm/test/Transforms/NewGVN/storeoverstore.ll b/llvm/test/Transforms/NewGVN/storeoverstore.ll
--- a/llvm/test/Transforms/NewGVN/storeoverstore.ll
+++ b/llvm/test/Transforms/NewGVN/storeoverstore.ll
@@ -15,13 +15,13 @@
 ; CHECK:       4:
 ; CHECK-NEXT:    br label [[TMP5]]
 ; CHECK:       5:
-; CHECK-NEXT:    [[DOT0:%.*]] = phi i32 [ 10, [[TMP4]] ], [ 5, [[TMP2:%.*]] ]
-; CHECK-NEXT:    br i1 [[TMP3]], label [[TMP6:%.*]], label [[TMP8:%.*]]
+; CHECK-NEXT:    [[PHIOFOPS:%.*]] = phi i32 [ 10, [[TMP2:%.*]] ], [ 15, [[TMP4]] ]
+; CHECK-NEXT:    [[DOT0:%.*]] = phi i32 [ 10, [[TMP4]] ], [ 5, [[TMP2]] ]
+; CHECK-NEXT:    br i1 [[TMP3]], label [[TMP6:%.*]], label [[TMP7:%.*]]
 ; CHECK:       6:
-; CHECK-NEXT:    [[TMP7:%.*]] = add nsw i32 [[DOT0]], 5
-; CHECK-NEXT:    br label [[TMP8]]
-; CHECK:       8:
-; CHECK-NEXT:    [[DOT1:%.*]] = phi i32 [ [[TMP7]], [[TMP6]] ], [ [[DOT0]], [[TMP5]] ]
+; CHECK-NEXT:    br label [[TMP7]]
+; CHECK:       7:
+; CHECK-NEXT:    [[DOT1:%.*]] = phi i32 [ [[PHIOFOPS]], [[TMP6]] ], [ [[DOT0]], [[TMP5]] ]
 ; CHECK-NEXT:    ret i32 [[DOT1]]
 ;
   store i32 5, ptr %0, align 4