2025-02-27  Jakub Jelinek  <jakub@redhat.com>

	PR ipa/119006
	* ipa-icf-gimple.cc (func_checker::compare_operand): If t1 and t2
	are ADDR_EXPRs, call operand_equal_p on their operands rather than on
	the ADDR_EXPRs themselves.  Formatting fix.

	* g++.dg/opt/pr119006.C: New test.

--- gcc/ipa-icf-gimple.cc.jj	2025-02-01 00:50:02.080774328 +0100
+++ gcc/ipa-icf-gimple.cc	2025-02-27 14:35:19.931183246 +0100
@@ -437,12 +437,23 @@ func_checker::compare_operand (tree t1,
 		 ("compare_ao_refs failed (dependence clique difference)");
       gcc_unreachable ();
     }
+  else if (TREE_CODE (t1) == ADDR_EXPR && TREE_CODE (t2) == ADDR_EXPR)
+    {
+      /* For ADDR_EXPR compare the operands of the ADDR_EXPR rather than
+	 the ADDR_EXPRs themselves.  operand_equal_p will compare the
+	 operands with OEP_ADDRESS_OF and only care about the value
+	 of the ADDR_EXPR, rather than e.g. types of MEM_REFs in there.
+	 Some optimizations use such details though, see PR119006.  */
+      if (operand_equal_p (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0),
+			   OEP_MATCH_SIDE_EFFECTS))
+	return true;
+      return return_false_with_msg ("operand_equal_p failed");
+    }
   else
     {
       if (operand_equal_p (t1, t2, OEP_MATCH_SIDE_EFFECTS))
 	return true;
-      return return_false_with_msg
-		 ("operand_equal_p failed");
+      return return_false_with_msg ("operand_equal_p failed");
     }
 }
 
--- gcc/testsuite/g++.dg/opt/pr119006.C.jj	2025-02-27 14:37:05.952707350 +0100
+++ gcc/testsuite/g++.dg/opt/pr119006.C	2025-02-27 14:36:29.251218260 +0100
@@ -0,0 +1,36 @@
+// PR ipa/119006
+// { dg-do run { target c++11 } }
+// { dg-options "-O2 -fwhole-program" }
+
+struct A {
+  bool operator== (const char *x) const { return x && !__builtin_strcmp (a, x); }
+  char a[11];
+};
+
+struct B {
+  bool operator== (const char *x) const { return x && !__builtin_strcmp (a, x); }
+  bool operator!= (const char *x) const { return !(*this == x); }
+  char a[128];
+};
+
+[[gnu::noinline,gnu::used]] int
+foo (const A& lhs, const char* rhs)
+{
+  return lhs == rhs;
+}
+
+constexpr const char *t = "abcdefghijklmno";
+
+[[gnu::noinline,gnu::used]] void
+bar (B x)
+{
+  if (x != t) __builtin_abort ();
+}
+
+int
+main ()
+{
+  B b;
+  __builtin_strcpy (b.a, t);
+  bar (b);
+}