2022-12-21  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/108166
	* tree-ssa-phiopt.cc (value_replacement): For the maybe_equal_p
	case turned into equal_p reset SSA_NAME_RANGE_INFO of phi result.

	* g++.dg/torture/pr108166.C: New test.

--- gcc/tree-ssa-phiopt.cc.jj	2022-10-28 11:00:53.970243821 +0200
+++ gcc/tree-ssa-phiopt.cc	2022-12-21 14:27:58.118326548 +0100
@@ -1491,6 +1491,12 @@ value_replacement (basic_block cond_bb,
 		  default:
 		    break;
 		  }
+	      if (equal_p)
+		/* After the optimization PHI result can have value
+		   which it couldn't have previously.
+		   We could instead of resetting it union the range
+		   info with oarg.  */
+		reset_flow_sensitive_info (gimple_phi_result (phi));
 	      if (equal_p && MAY_HAVE_DEBUG_BIND_STMTS)
 		{
 		  imm_use_iterator imm_iter;
--- gcc/testsuite/g++.dg/torture/pr108166.C.jj	2022-12-21 14:31:02.638661322 +0100
+++ gcc/testsuite/g++.dg/torture/pr108166.C	2022-12-21 14:30:45.441909725 +0100
@@ -0,0 +1,26 @@
+// PR tree-optimization/108166
+// { dg-do run }
+
+bool a, b;
+int d, c;
+
+const int &
+foo (const int &f, const int &g)
+{
+  return !f ? f : g;
+}
+
+__attribute__((noipa)) void
+bar (int)
+{
+}
+
+int
+main ()
+{
+  c = foo (b, 0) > ((b ? d : b) ?: 8);
+  a = b ? d : b;
+  bar (a);
+  if (a != 0)
+    __builtin_abort ();
+}