--- gcc/cp/cp-tree.h.jj	2023-12-05 09:06:06.140878013 +0100
+++ gcc/cp/cp-tree.h	2023-12-05 16:21:05.564736203 +0100
@@ -7918,6 +7918,7 @@ extern tree most_general_lambda			(tree)
 extern tree finish_omp_target			(location_t, tree, tree, bool);
 extern void finish_omp_target_clauses		(location_t, tree, tree *);
 extern void maybe_warn_unparenthesized_assignment (tree, tsubst_flags_t);
+extern tree cp_check_pragma_unroll		(location_t, tree);
 
 /* in tree.cc */
 extern int cp_tree_operand_length		(const_tree);
--- gcc/cp/semantics.cc.jj	2023-12-04 08:59:06.888357091 +0100
+++ gcc/cp/semantics.cc	2023-12-05 16:56:03.718410332 +0100
@@ -13016,4 +13016,33 @@ cp_build_bit_cast (location_t loc, tree
   return ret;
 }
 
+/* Diagnose invalid #pragma GCC unroll argument and adjust
+   it if needed.  */
+
+tree
+cp_check_pragma_unroll (location_t loc, tree unroll)
+{
+  HOST_WIDE_INT lunroll = 0;
+  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 (loc, "%<#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;
+    }
+  return unroll;
+}
+
 #include "gt-cp-semantics.h"
--- gcc/cp/parser.cc.jj	2023-12-05 09:05:37.533281014 +0100
+++ gcc/cp/parser.cc	2023-12-05 16:18:32.224909370 +0100
@@ -50243,27 +50243,7 @@ cp_parser_pragma_unroll (cp_parser *pars
 {
   location_t location = cp_lexer_peek_token (parser->lexer)->location;
   tree unroll = cp_parser_constant_expression (parser);
-  unroll = fold_non_dependent_expr (unroll);
-  HOST_WIDE_INT lunroll = 0;
-  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 (location, "%<#pragma GCC unroll%> requires an"
-		" assignment-expression that evaluates to a non-negative"
-		" integral constant less than %u", USHRT_MAX);
-      unroll = NULL_TREE;
-    }
-  else if (TREE_CODE (unroll) == INTEGER_CST)
-    {
-      unroll = fold_convert (integer_type_node, unroll);
-      if (integer_zerop (unroll))
-	unroll = integer_one_node;
-    }
+  unroll = cp_check_pragma_unroll (location, fold_non_dependent_expr (unroll));
   cp_parser_skip_to_pragma_eol (parser, pragma_tok);
   return unroll;
 }
--- gcc/cp/pt.cc.jj	2023-12-05 09:06:06.175877520 +0100
+++ gcc/cp/pt.cc	2023-12-05 16:48:05.641109116 +0100
@@ -18407,22 +18407,24 @@ tsubst_stmt (tree t, tree args, tsubst_f
 					complain, in_decl, decomp);
 	  }
 
+	tree unroll = RECUR (RANGE_FOR_UNROLL (t));
+	if (unroll)
+	  unroll
+	    = cp_check_pragma_unroll (EXPR_LOCATION (RANGE_FOR_UNROLL (t)),
+				      unroll);
 	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));
@@ -21506,30 +21508,8 @@ tsubst_expr (tree t, tree args, tsubst_f
 	tree op3 = RECUR (TREE_OPERAND (t, 2));
 	if (TREE_CODE (op2) == INTEGER_CST
 	    && wi::to_widest (op2) == (int) annot_expr_unroll_kind)
-	  {
-	    HOST_WIDE_INT lunroll;
-	    if (type_dependent_expression_p (op3))
-	      ;
-	    else if (!INTEGRAL_TYPE_P (TREE_TYPE (op3))
-		     || (!value_dependent_expression_p (op3)
-			 && (!tree_fits_shwi_p (op3)
-			     || (lunroll = tree_to_shwi (op3)) < 0
-			     || lunroll >= USHRT_MAX)))
-	      {
-		error_at (EXPR_LOCATION (TREE_OPERAND (t, 2)),
-			  "%<#pragma GCC unroll%> requires an "
-			  "assignment-expression that evaluates to a "
-			  "non-negative integral constant less than %u",
-			  USHRT_MAX);
-		op3 = integer_one_node;
-	      }
-	    else if (TREE_CODE (op3) == INTEGER_CST)
-	      {
-		op3 = fold_convert (integer_type_node, op3);
-		if (integer_zerop (op3))
-		  op3 = integer_one_node;
-	      }
-	  }
+	  op3 = cp_check_pragma_unroll (EXPR_LOCATION (TREE_OPERAND (t, 2)),
+					op3);
 	RETURN (build3_loc (EXPR_LOCATION (t), ANNOTATE_EXPR,
 			    TREE_TYPE (op1), op1, op2, op3));
       }
--- gcc/testsuite/g++.dg/ext/unroll-2.C.jj	2023-12-04 11:55:52.154142189 +0100
+++ gcc/testsuite/g++.dg/ext/unroll-2.C	2023-12-05 16:17:29.976792279 +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	2023-12-04 11:55:52.154142189 +0100
+++ gcc/testsuite/g++.dg/ext/unroll-3.C	2023-12-05 16:17:29.988792108 +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	2023-12-05 16:17:29.988792108 +0100
+++ gcc/testsuite/g++.dg/ext/unroll-7.C	2023-12-05 16:17:29.988792108 +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	2023-12-05 16:17:29.988792108 +0100
+++ gcc/testsuite/g++.dg/ext/unroll-8.C	2023-12-05 16:17:29.988792108 +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);
+}
