Index: llvm/include/llvm/IR/InstrTypes.h
===================================================================
--- llvm/include/llvm/IR/InstrTypes.h
+++ llvm/include/llvm/IR/InstrTypes.h
@@ -1818,14 +1818,14 @@
 
   /// Determine if the call does not access or only reads memory.
   bool onlyReadsMemory() const {
-    return doesNotAccessMemory() || hasFnAttr(Attribute::ReadOnly);
+    return hasImpliedFnAttr(Attribute::ReadOnly);
   }
 
   void setOnlyReadsMemory() { addFnAttr(Attribute::ReadOnly); }
 
   /// Determine if the call does not access or only writes memory.
   bool onlyWritesMemory() const {
-    return doesNotAccessMemory() || hasFnAttr(Attribute::WriteOnly);
+    return hasImpliedFnAttr(Attribute::WriteOnly);
   }
   void setOnlyWritesMemory() { addFnAttr(Attribute::WriteOnly); }
 
@@ -2113,6 +2113,9 @@
 
     case Attribute::ReadOnly:
       return hasClobberingOperandBundles();
+
+    case Attribute::WriteOnly:
+      return hasReadingOperandBundles();
     }
 
     llvm_unreachable("switch has a default case!");
@@ -2285,6 +2288,26 @@
     return hasFnAttrOnCalledFunction(Kind);
   }
 
+  // A specialized version of hasFnAttrImpl for when the caller wants to
+  // know if an attribute's semantics are implied, not whether the attribute
+  // is actually present.  This distinction only exists when checking whether
+  // something is readonly or writeonly since readnone implies both.  The case
+  // which motivates the specialized code is a callee with readnone, and an
+  // operand bundle on the call which disallows readnone but not either
+  // readonly or writeonly.
+  bool hasImpliedFnAttr(Attribute::AttrKind Kind) const {
+    assert((Kind == Attribute::ReadOnly || Kind == Attribute::WriteOnly) &&
+           "use hasFnAttrImpl instead");
+    if (Attrs.hasFnAttr(Kind) || Attrs.hasFnAttr(Attribute::ReadNone))
+      return true;
+
+    if (isFnAttrDisallowedByOpBundle(Kind))
+      return false;
+
+    return hasFnAttrOnCalledFunction(Kind) ||
+      hasFnAttrOnCalledFunction(Attribute::ReadNone);
+  }
+
   /// Determine whether the return value has the given attribute. Supports
   /// Attribute::AttrKind and StringRef as \p AttrKind types.
   template <typename AttrKind> bool hasRetAttrImpl(AttrKind Kind) const {
Index: llvm/test/Transforms/InstCombine/trivial-dse-calls.ll
===================================================================
--- llvm/test/Transforms/InstCombine/trivial-dse-calls.ll
+++ llvm/test/Transforms/InstCombine/trivial-dse-calls.ll
@@ -253,7 +253,6 @@
 
 define void @test_readnone_with_deopt() {
 ; CHECK-LABEL: @test_readnone_with_deopt(
-; CHECK-NEXT:    call void @removable_readnone() [ "deopt"() ]
 ; CHECK-NEXT:    ret void
 ;
   call void @removable_readnone() [ "deopt"() ]