--- gcc/cp/pt.cc.jj	2023-12-04 08:59:06.000000000 +0100
+++ gcc/cp/pt.cc	2023-12-04 10:49:38.149254907 +0100
@@ -18407,22 +18407,46 @@ tsubst_stmt (tree t, tree args, tsubst_f
 					complain, in_decl, decomp);
 	  }
 
+	tree unroll = RECUR (RANGE_FOR_UNROLL (t));
+	if (unroll)
+	  {
+	    HOST_WIDE_INT lunroll;
+	    if (type_dependent_expression_p (unroll))
+	      ;
+	    else if (!INTEGRAL_TYPE_P (TREE_TYPE (unroll))
+		     || (!value_dependent_expression_p (unroll)
+			 && (!tree_fits_shwi_p (unroll)
+			     || (lunroll = tree_to_shwi (unroll)) < 0
+			     || lunroll >= USHRT_MAX)))
+	      {
+		error_at (EXPR_LOCATION (RANGE_FOR_UNROLL (t)),
+			  "%<#pragma GCC unroll%> requires an "
+			  "assignment-expression that evaluates to a "
+			  "non-negative integral constant less than %u",
+			  USHRT_MAX);
+		unroll = integer_one_node;
+	      }
+	    else if (TREE_CODE (unroll) == INTEGER_CST)
+	      {
+		unroll = fold_convert (integer_type_node, unroll);
+		if (integer_zerop (unroll))
+		  unroll = integer_one_node;
+	      }
+	  }
+
 	if (processing_template_decl)
 	  {
 	    RANGE_FOR_IVDEP (stmt) = RANGE_FOR_IVDEP (t);
-	    RANGE_FOR_UNROLL (stmt) = RANGE_FOR_UNROLL (t);
+	    RANGE_FOR_UNROLL (stmt) = unroll;
 	    RANGE_FOR_NOVECTOR (stmt) = RANGE_FOR_NOVECTOR (t);
 	    finish_range_for_decl (stmt, decl, expr);
 	    if (decomp && decl != error_mark_node)
 	      cp_finish_decomp (decl, decomp);
 	  }
 	else
-	  {
-	    tree unroll = RECUR (RANGE_FOR_UNROLL (t));
-	    stmt = cp_convert_range_for (stmt, decl, expr, decomp,
-					 RANGE_FOR_IVDEP (t), unroll,
-					 RANGE_FOR_NOVECTOR (t));
-	  }
+	  stmt = cp_convert_range_for (stmt, decl, expr, decomp,
+				       RANGE_FOR_IVDEP (t), unroll,
+				       RANGE_FOR_NOVECTOR (t));
 
 	bool prev = note_iteration_stmt_body_start ();
         RECUR (RANGE_FOR_BODY (t));
--- gcc/testsuite/g++.dg/ext/unroll-2.C.jj	2020-01-12 11:54:37.172401958 +0100
+++ gcc/testsuite/g++.dg/ext/unroll-2.C	2023-12-04 10:17:00.390997063 +0100
@@ -1,6 +1,5 @@
-// { dg-do compile }
+// { dg-do compile { target c++11 } }
 // { dg-options "-O2 -fdump-tree-cunrolli-details" }
-// { dg-skip-if "range for" { *-*-* } { "-std=gnu++98" } { "" } }
 
 void
 foo (int (&a)[8], int *b, int *c)
--- gcc/testsuite/g++.dg/ext/unroll-3.C.jj	2020-01-12 11:54:37.172401958 +0100
+++ gcc/testsuite/g++.dg/ext/unroll-3.C	2023-12-04 10:17:13.526813516 +0100
@@ -1,6 +1,5 @@
-// { dg-do compile }
+// { dg-do compile { target c++11 } }
 // { dg-options "-O2 -fdump-tree-cunrolli-details" }
-// { dg-skip-if "range for" { *-*-* } { "-std=gnu++98" } { "" } }
 
 template <typename T>
 void
--- gcc/testsuite/g++.dg/ext/unroll-7.C.jj	2023-12-04 10:17:53.481255222 +0100
+++ gcc/testsuite/g++.dg/ext/unroll-7.C	2023-12-04 10:39:23.258115349 +0100
@@ -0,0 +1,45 @@
+// PR c++/112795
+// { dg-do compile { target c++11 } }
+// { dg-options "-O2 -fdump-tree-cunrolli-details" }
+
+void baz (int);
+constexpr int n = 3;
+constexpr int m = 7;
+
+template <typename T>
+void
+foo (int (&a)[3], T b)
+{
+#pragma GCC unroll(n)
+  for (auto i : a)
+    baz (i);
+#pragma GCC unroll(m)
+  for (auto i : b)
+    baz (i);
+}
+
+template <int N>
+void
+bar (int (&a)[N])
+{
+#pragma GCC unroll(N)
+  for (auto i : a)
+    baz (i);
+}
+
+void
+qux ()
+{
+  int a[3] = { 1, 2, 3 };
+  int b[7] = { 4, 5, 6, 7, 8, 9, 10 };
+  int c[6] = { 11, 12, 13, 14, 15, 16 };
+  int d[10] = { 17, 18, 19, 20, 21, 22, 23, 24, 25, 26 };
+  foo <int (&)[7]> (a, b);
+  bar <6> (c);
+  bar <10> (d);
+}
+
+// { dg-final { scan-tree-dump "loop with 3 iterations completely unrolled" "cunrolli" } }
+// { dg-final { scan-tree-dump "loop with 6 iterations completely unrolled" "cunrolli" } }
+// { dg-final { scan-tree-dump "loop with 7 iterations completely unrolled" "cunrolli" } }
+// { dg-final { scan-tree-dump "loop with 10 iterations completely unrolled" "cunrolli" } }
--- gcc/testsuite/g++.dg/ext/unroll-8.C.jj	2023-12-04 10:17:56.763209358 +0100
+++ gcc/testsuite/g++.dg/ext/unroll-8.C	2023-12-04 10:44:58.531217053 +0100
@@ -0,0 +1,86 @@
+// PR c++/112795
+// { dg-do compile { target c++11 } }
+
+void
+foo (int (&a)[3])
+{
+  #pragma GCC unroll 1.0f			// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll 0xffffffffffffffffULL	// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll -42			// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+}
+
+template <int N, typename U>
+void
+bar (U a)
+{
+  #pragma GCC unroll 1.0f			// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll 0xffffffffffffffffULL	// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll -42			// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+}
+
+template <typename T, int N, typename U>
+void
+baz (U a)
+{
+  #pragma GCC unroll (N + 1.0f)			// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll (N + 0xffffffffffffffffULL)
+  for (auto i : a)
+    ;
+  #pragma GCC unroll (N - 42)
+  for (auto i : a)
+    ;
+  #pragma GCC unroll ((T) 1.0f)
+  for (auto i : a)
+    ;
+  #pragma GCC unroll ((T) 0xffffffffffffffffULL)
+  for (auto i : a)
+    ;
+  #pragma GCC unroll ((T) -42)
+  for (auto i : a)
+    ;
+}
+
+template <typename T, int N, typename U>
+void
+qux (U a)
+{
+  #pragma GCC unroll (N + 1.0f)			// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll (N + 0xffffffffffffffffULL)// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll (N - 42)			// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll ((T) 1.0f)			// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll ((T) 0xffffffffffffffffULL)// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+  #pragma GCC unroll ((T) -42)			// { dg-error "'#pragma GCC unroll' requires an assignment-expression that evaluates to a non-negative integral constant less than" }
+  for (auto i : a)
+    ;
+}
+
+void
+corge ()
+{
+  int a[3] = { 1, 2, 3 };
+  qux <float, 0, int (&)[3]> (a);
+}
