[ARM] Enable tail call optimization for long call

gcc/

	* config/arm/predicates.md (call_insn_operand): Add long_call check.
	* config/arm/arm.md (sibcall, sibcall_value): Force the address to
	reg for long_call.
	* config/arm/arm.c (arm_function_ok_for_sibcall): Remove long_call
	restriction.

gcc/testsuite

	* gcc.target/arm/tail-long-call.c: New test.

From-SVN: r209808

gcc/ChangeLog

+2014-04-25  Jiong Wang  <jiong.wang@arm.com>
+
+	* config/arm/predicates.md (call_insn_operand): Add long_call check.
+	* config/arm/arm.md (sibcall, sibcall_value): Force the address to
+	reg for long_call.
+	* config/arm/arm.c (arm_function_ok_for_sibcall): Remove long_call
+	restriction.
+
 2014-04-25  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* config/arm/arm.c (arm_cortex_a8_tune): Initialise

gcc/config/arm/arm.c

@@ -6217,11 +6217,6 @@ arm_function_ok_for_sibcall (tree decl, tree exp)
   if (TARGET_VXWORKS_RTP && flag_pic && !targetm.binds_local_p (decl))
     return false;
 
-  /* Cannot tail-call to long calls, since these are out of range of
-     a branch instruction.  */
-  if (decl && arm_is_long_call_p (decl))
-    return false;
-
   /* If we are interworking and the function is not declared static
      then we can't tail-call it unless we know that it exists in this
      compilation unit (since it might be a Thumb routine).  */

gcc/config/arm/arm.md

@@ -9367,8 +9367,10 @@
   "TARGET_32BIT"
   "
   {
-    if (!REG_P (XEXP (operands[0], 0))
-       && (GET_CODE (XEXP (operands[0], 0)) != SYMBOL_REF))
+    if ((!REG_P (XEXP (operands[0], 0))
+	 && GET_CODE (XEXP (operands[0], 0)) != SYMBOL_REF)
+	|| (GET_CODE (XEXP (operands[0], 0)) == SYMBOL_REF
+	    && arm_is_long_call_p (SYMBOL_REF_DECL (XEXP (operands[0], 0)))))
      XEXP (operands[0], 0) = force_reg (SImode, XEXP (operands[0], 0));
 
     if (operands[2] == NULL_RTX)
@@ -9385,8 +9387,10 @@
   "TARGET_32BIT"
   "
   {
-    if (!REG_P (XEXP (operands[1], 0)) &&
-       (GET_CODE (XEXP (operands[1],0)) != SYMBOL_REF))
+    if ((!REG_P (XEXP (operands[1], 0))
+	 && GET_CODE (XEXP (operands[1], 0)) != SYMBOL_REF)
+	|| (GET_CODE (XEXP (operands[1], 0)) == SYMBOL_REF
+	    && arm_is_long_call_p (SYMBOL_REF_DECL (XEXP (operands[1], 0)))))
      XEXP (operands[1], 0) = force_reg (SImode, XEXP (operands[1], 0));
 
     if (operands[3] == NULL_RTX)

gcc/config/arm/predicates.md

@@ -681,5 +681,6 @@
        (match_code "reg" "0")))
 
 (define_predicate "call_insn_operand"
-  (ior (match_code "symbol_ref")
+  (ior (and (match_code "symbol_ref")
+	    (match_test "!arm_is_long_call_p (SYMBOL_REF_DECL (op))"))
        (match_operand 0 "s_register_operand")))

gcc/testsuite/ChangeLog

+2014-04-25  Jiong Wang  <jiong.wang@arm.com>
+
+	* gcc.target/arm/tail-long-call.c: New test.
+
 2014-04-25  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	PR tree-optimization/60930

gcc/testsuite/gcc.target/arm/tail-long-call.c

+/* { dg-skip-if "need at least armv5te" { *-*-* } { "-march=armv[234]*" "-mthumb" } { "" } } */
+/* { dg-options "-O2 -march=armv5te -marm" } */
+/* { dg-final { scan-assembler "bx" } } */
+/* { dg-final { scan-assembler-not "blx" } } */
+
+int lcal (int) __attribute__ ((long_call));
+
+int
+dec (int a)
+{
+  return lcal (a);
+}