Index: lib/Transforms/InstCombine/InstCombineCalls.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -2895,6 +2895,18 @@
       GuardB->setCallingConv(CC);
       return eraseInstFromFunction(*II);
     }
+
+    // guard(!(a || b)) -> guard(!a); guard(!b);
+    if (match(IIOperand, m_Not(m_Or(m_Value(A), m_Value(B))))) {
+      CallInst *GuardA = Builder->CreateCall(GuardIntrinsic, Builder->CreateNot(A),
+                                             {DeoptOB}, II->getName());
+      CallInst *GuardB = Builder->CreateCall(GuardIntrinsic, Builder->CreateNot(B),
+                                             {DeoptOB}, II->getName());
+      auto CC = II->getCallingConv();
+      GuardA->setCallingConv(CC);
+      GuardB->setCallingConv(CC);
+      return eraseInstFromFunction(*II);
+    }
     break;
   }
   }
Index: test/Transforms/InstCombine/call-guard.ll
===================================================================
--- test/Transforms/InstCombine/call-guard.ll
+++ test/Transforms/InstCombine/call-guard.ll
@@ -48,3 +48,29 @@
   call cc99 void(i1, ...) @llvm.experimental.guard( i1 %C )[ "deopt"() ]
   ret void
 }
+
+define void @test_guard_not_or(i1 %A, i1 %B) {
+; CHECK-LABEL: @test_guard_not_or(
+; CHECK-NEXT:    %1 = xor i1 %A, true
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %1) [ "deopt"() ]
+; CHECK-NEXT:    %2 = xor i1 %B, true
+; CHECK-NEXT:    call void (i1, ...) @llvm.experimental.guard(i1 %2) [ "deopt"() ]
+; CHECK-NEXT:    ret void
+  %C = or i1 %A, %B
+  %D = xor i1 %C, true
+  call void(i1, ...) @llvm.experimental.guard( i1 %D )[ "deopt"() ]
+  ret void
+}
+
+define void @test_guard_not_or_cc99(i1 %A, i1 %B) {
+; CHECK-LABEL: @test_guard_not_or_cc99(
+; CHECK-NEXT:    %1 = xor i1 %A, true
+; CHECK-NEXT:    call cc99 void (i1, ...) @llvm.experimental.guard(i1 %1) [ "deopt"() ]
+; CHECK-NEXT:    %2 = xor i1 %B, true
+; CHECK-NEXT:    call cc99 void (i1, ...) @llvm.experimental.guard(i1 %2) [ "deopt"() ]
+; CHECK-NEXT:    ret void
+  %C = or i1 %A, %B
+  %D = xor i1 %C, true
+  call cc99 void(i1, ...) @llvm.experimental.guard( i1 %D )[ "deopt"() ]
+  ret void
+}