re PR target/38056 (Missed tail calls on ia64)

	PR target/38056
	* config/ia64/ia64.c (ia64_function_ok_for_sibcall): Check
	TARGET_CONST_GP.
	* gcc.target/ia64/sibcall-opt-1.c: New test.
	* gcc.target/ia64/sibcall-opt-2.c: New test.

From-SVN: r144168

gcc/ChangeLog

+2009-02-13  Steve Ellcey  <sje@cup.hp.com>
+
+	PR target/38056
+	* config/ia64/ia64.c (ia64_function_ok_for_sibcall): Check
+	TARGET_CONST_GP.
+
 2009-02-13  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/39149

gcc/config/ia64/ia64.c

@@ -4365,8 +4365,9 @@ ia64_function_ok_for_sibcall (tree decl, tree exp ATTRIBUTE_UNUSED)
     return false;
 
   /* We must always return with our current GP.  This means we can
-     only sibcall to functions defined in the current module.  */
-  return decl && (*targetm.binds_local_p) (decl);
+     only sibcall to functions defined in the current module unless
+     TARGET_CONST_GP is set to true.  */
+  return (decl && (*targetm.binds_local_p) (decl)) || TARGET_CONST_GP;
 }
 
 

gcc/testsuite/ChangeLog

+2009-02-13  Steve Ellcey  <sje@cup.hp.com>
+
+	PR target/38056
+	* gcc.target/ia64/sibcall-opt-1.c: New test.
+	* gcc.target/ia64/sibcall-opt-2.c: New test.
+
 2009-02-13  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/36528

gcc/testsuite/gcc.target/ia64/sibcall-opt-1.c

+/* PR target/38056.  Do not do sibcall optimization across object file
+   boundery when -mconstant-gp is not used.  */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler "br.call.*bar" } } */
+
+int bar(int x);
+
+int foo(int x)
+{
+  return (bar(x + 1));
+}

gcc/testsuite/gcc.target/ia64/sibcall-opt-2.c

+/* PR target/38056.  Do sibcall optimization across object file
+   boundery when -mconstant-gp is used.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -mconstant-gp" } */
+/* { dg-final { scan-assembler-not "br.call.*bar" } } */
+
+int bar(int x);
+
+int foo(int x)
+{
+  return (bar(x + 1));
+}