diff --git a/lib/checkcondition.cpp b/lib/checkcondition.cpp
index 3618230a9..21d791079 100644
--- a/lib/checkcondition.cpp
+++ b/lib/checkcondition.cpp
@@ -366,11 +366,18 @@ bool CheckCondition::isOppositeCond(bool isNot, const Token * const cond1, const
     if (!cond1 || !cond2)
         return false;
 
-    if (cond1->str() == "!")
+    if (cond1->str() == "!") {
+        if (cond2->str() == "!=") {
+            if (cond2->astOperand1()->str() == "0")
+                return isSameExpression(_tokenizer, cond1->astOperand1(), cond2->astOperand2(), constFunctions);
+            if (cond2->astOperand2()->str() == "0")
+                return isSameExpression(_tokenizer, cond1->astOperand1(), cond2->astOperand1(), constFunctions);
+        }
         return isSameExpression(_tokenizer, cond1->astOperand1(), cond2, constFunctions);
+    }
 
     if (cond2->str() == "!")
-        return isSameExpression(_tokenizer, cond1, cond2->astOperand1(), constFunctions);
+        return isOppositeCond(isNot, cond2, cond1, constFunctions);
 
     if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
         return false;
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 151528942..abe18f775 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -3703,7 +3703,6 @@ bool Tokenizer::simplifyTokenList2()
     simplifyIfAndWhileAssign();
     simplifyRedundantParentheses();
     simplifyIfNot();
-    simplifyIfNotNull();
     simplifyIfSameInnerCondition();
     simplifyNestedStrcat();
     simplifyFuncInWhile();
@@ -6069,63 +6068,6 @@ void Tokenizer::simplifyIfNot()
     }
 }
 
-
-void Tokenizer::simplifyIfNotNull()
-{
-    for (Token *tok = list.front(); tok; tok = tok->next()) {
-        Token *deleteFrom = nullptr;
-
-        // Remove 'x = x != 0;'
-        if (Token::simpleMatch(tok, "=")) {
-            if (Token::Match(tok->tokAt(-2), "[;{}] %name%")) {
-                const std::string& varname(tok->previous()->str());
-
-                if (Token::simpleMatch(tok->next(), (varname + " != 0 ;").c_str()) ||
-                    Token::simpleMatch(tok->next(), ("0 != " + varname + " ;").c_str())) {
-                    tok = tok->tokAt(-2);
-                    tok->deleteNext(6);
-                }
-            }
-            continue;
-        }
-
-        if (Token::Match(tok, "==|!= ("))
-            tok = tok->linkAt(1);
-
-        if (Token::Match(tok, "(|&&|%oror%")) {
-            tok = tok->next();
-
-            if (!tok)
-                break;
-
-            if (Token::Match(tok, "0 != %name%|(")) {
-                deleteFrom = tok->previous();
-                if (tok->tokAt(2))
-                    tok->tokAt(2)->isPointerCompare(true);
-            }
-
-            else if (Token::Match(tok, "%name% != 0")) {
-                deleteFrom = tok;
-                tok->isPointerCompare(true);
-                tok->isExpandedMacro(tok->isExpandedMacro() || tok->tokAt(2)->isExpandedMacro());
-            }
-
-            else if (Token::Match(tok, "%name% .|:: %name% != 0")) {
-                tok = tok->tokAt(2);
-                deleteFrom = tok;
-                tok->isPointerCompare(true);
-                tok->isExpandedMacro(tok->isExpandedMacro() || tok->tokAt(2)->isExpandedMacro());
-            }
-        }
-
-        if (deleteFrom) {
-            Token::eraseTokens(deleteFrom, deleteFrom->tokAt(3));
-            tok = deleteFrom;
-        }
-    }
-}
-
-
 void Tokenizer::simplifyIfSameInnerCondition()
 {
     // same inner condition
diff --git a/lib/tokenize.h b/lib/tokenize.h
index c793a73b1..4e3869314 100644
--- a/lib/tokenize.h
+++ b/lib/tokenize.h
@@ -305,13 +305,6 @@ public:
      */
     void simplifyIfNot();
 
-    /**
-     * simplify if-not NULL
-     * Example: "if(0!=x);" => "if(x);"
-     * Special case: 'x = (0 != x);' is removed.
-     */
-    void simplifyIfNotNull();
-
     /** @brief simplify if (a) { if (a) */
     void simplifyIfSameInnerCondition();
 
diff --git a/test/testcondition.cpp b/test/testcondition.cpp
index 2e1862877..ed6e41388 100644
--- a/test/testcondition.cpp
+++ b/test/testcondition.cpp
@@ -1389,7 +1389,7 @@ private:
               "   int y = rand(), z = rand();\n"
               "   if (y==0 || y!=0 && z);\n"
               "}", false);
-        ASSERT_EQUALS("[test.cpp:3]: (style) Redundant condition: y. 'A && (!A || B)' is equivalent to 'A || B'\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:3]: (style) Redundant condition: y!=0. 'A && (!A || B)' is equivalent to 'A || B'\n", errout.str());
 
         check("void f() {\n"
               "  if (x>0 || (x<0 && y)) {}\n"
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index 36936ba61..2ce40841d 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -99,7 +99,6 @@ private:
 
         // "if(0==x)" => "if(!x)"
         TEST_CASE(simplifyIfNot);
-        TEST_CASE(simplifyIfNotNull);
 
         TEST_CASE(combine_wstrings);
 
@@ -1687,13 +1686,6 @@ private:
         ASSERT_EQUALS("if ( ! ( ! fclose ( fd ) ) ) { ; }", tok("if(!(fclose(fd) == 0));"));
     }
 
-    void simplifyIfNotNull() {
-        const char code[] = "void f(int x) {\n"
-                            "    x = (x != 0);\n"
-                            "}";
-        ASSERT_EQUALS("void f ( int x ) { }", tok(code, true));
-    }
-
     void not1() {
         ASSERT_EQUALS("void f ( ) { if ( ! p ) { ; } }", tok("void f() { if (not p); }", "test.c", false));
         ASSERT_EQUALS("void f ( ) { if ( p && ! q ) { ; } }", tok("void f() { if (p && not q); }", "test.c", false));
diff --git a/test/testtokenize.cpp b/test/testtokenize.cpp
index 9d727b261..acc8cbfab 100644
--- a/test/testtokenize.cpp
+++ b/test/testtokenize.cpp
@@ -127,8 +127,6 @@ private:
         TEST_CASE(forAddBraces1);
         TEST_CASE(forAddBraces2); // #5088
 
-        TEST_CASE(pointers_condition);
-
         TEST_CASE(simplifyKnownVariables1);
         TEST_CASE(simplifyKnownVariables2);
         TEST_CASE(simplifyKnownVariables3);
@@ -1082,47 +1080,6 @@ private:
         ASSERT_EQUALS(";\n\nasm ( \"\"mov ax,bx\"\" ) ;", tokenizeAndStringify(";\n\n__asm__ volatile ( \"mov ax,bx\" );", true));
     }
 
-
-    void pointers_condition() {
-        ASSERT_EQUALS("( p )", tokenizeAndStringify("( p != NULL )", true));
-        ASSERT_EQUALS("( p )", tokenizeAndStringify("( NULL != p )", true));
-        ASSERT_EQUALS("( this . p )", tokenizeAndStringify("( this->p != NULL )", true));
-        ASSERT_EQUALS("( this . p )", tokenizeAndStringify("( NULL != this->p )", true));
-        ASSERT_EQUALS("( Foo :: p )", tokenizeAndStringify("( Foo::p != NULL )", true));
-        ASSERT_EQUALS("( Foo :: p )", tokenizeAndStringify("( NULL != Foo::p )", true));
-
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( p == NULL )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( NULL == p )", true));
-        ASSERT_EQUALS("( ! this . p )", tokenizeAndStringify("( this->p == NULL )", true));
-        ASSERT_EQUALS("( ! this . p )", tokenizeAndStringify("( NULL == this->p )", true));
-        ASSERT_EQUALS("( ! Foo :: p )", tokenizeAndStringify("( Foo::p == NULL )", true));
-        ASSERT_EQUALS("( ! Foo :: p )", tokenizeAndStringify("( NULL == Foo::p )", true));
-
-        ASSERT_EQUALS("( p1 || ! p2 )", tokenizeAndStringify("( p1 != NULL || p2 == NULL )", true));
-        ASSERT_EQUALS("( p1 && ! p2 )", tokenizeAndStringify("( p1 != NULL && p2 == NULL )", true));
-        ASSERT_EQUALS("a & & b", tokenizeAndStringify("a & &b", true));
-
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( p == false )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( p == 0 )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( p == '\\0' )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( p == 0L )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( p == 0UL )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( p == 0ul )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( p == 0l )", true));
-
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( false == p )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( 0 == p )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( '\\0' == p )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( 0L == p )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( 0UL == p )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( 0ul == p )", true));
-        ASSERT_EQUALS("( ! p )", tokenizeAndStringify("( 0l == p )", true));
-
-        // not pointer
-        ASSERT_EQUALS("( x != ( y != 0 ) )", tokenizeAndStringify("( x != ( y != 0 ) )", false));
-    }
-
-
     void ifAddBraces1() {
         const char code[] = "void f()\n"
                             "{\n"