[AArch64] Enable shrink wrapping.

From-SVN: r215508

gcc/ChangeLog

+2014-09-23  Renlin Li  <renlin.li@arm.com>
+
+	* config/aarch64/aarch64.md (return): New.
+	(simple_return): Likewise.
+	* config/aarch64/aarch64.c (aarch64_use_return_insn_p): New.
+	* config/aarch64/aarch64-protos.h (aarch64_use_return_insn_p): New.
+
 2014-09-23  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* common/config/aarch64/aarch64-common.c:

gcc/config/aarch64/aarch64-protos.h

@@ -213,6 +213,7 @@ bool aarch64_simd_valid_immediate (rtx, enum machine_mode, bool,
 				   struct simd_immediate_info *);
 bool aarch64_symbolic_address_p (rtx);
 bool aarch64_uimm12_shift (HOST_WIDE_INT);
+bool aarch64_use_return_insn_p (void);
 const char *aarch64_output_casesi (rtx *);
 const char *aarch64_rewrite_selected_cpu (const char *name);
 

gcc/config/aarch64/aarch64.c

@@ -2340,6 +2340,26 @@ aarch64_expand_prologue (void)
     }
 }
 
+/* Return TRUE if we can use a simple_return insn.
+
+   This function checks whether the callee saved stack is empty, which
+   means no restore actions are need. The pro_and_epilogue will use
+   this to check whether shrink-wrapping opt is feasible.  */
+
+bool
+aarch64_use_return_insn_p (void)
+{
+  if (!reload_completed)
+    return false;
+
+  if (crtl->profile)
+    return false;
+
+  aarch64_layout_frame ();
+
+  return cfun->machine->frame.frame_size == 0;
+}
+
 /* Generate the epilogue instructions for returning from a function.  */
 void
 aarch64_expand_epilogue (bool for_sibcall)

gcc/config/aarch64/aarch64.md

@@ -360,6 +360,19 @@
   [(set_attr "type" "branch")]
 )
 
+(define_expand "return"
+  [(simple_return)]
+  "aarch64_use_return_insn_p ()"
+  ""
+)
+
+(define_insn "simple_return"
+  [(simple_return)]
+  ""
+  "ret"
+  [(set_attr "type" "branch")]
+)
+
 (define_insn "eh_return"
   [(unspec_volatile [(match_operand:DI 0 "register_operand" "r")]
     UNSPECV_EH_RETURN)]

gcc/testsuite/ChangeLog

+2014-09-24  Renlin Li  <renlin.li@arm.com>
+
+	* gcc.dg/ira-shrinkwrap-prep-1.c: Enable aarch64.
+	* gcc.dg/ira-shrinkwrap-prep-2.c: Likewise.
+	* gcc.dg/pr10474.c: Likewise.
+
 2014-09-20  Mark Wielaard  <mjw@redhat.com>
 
 	* gcc.dg/guality/const-volatile.c (i): Mark as used.

gcc/testsuite/gcc.dg/ira-shrinkwrap-prep-1.c

-/* { dg-do compile { target { { x86_64-*-* && lp64 } || { { powerpc*-*-* && lp64 } || arm_nothumb } } } } */
+/* { dg-do compile { target { { x86_64-*-* && lp64 } || { { powerpc*-*-* && lp64 } || { arm_nothumb || { aarch64*-*-* && lp64 } } } } } } */
 /* { dg-options "-O3 -fdump-rtl-ira -fdump-rtl-pro_and_epilogue -fno-use-caller-save"  } */
 
 long __attribute__((noinline, noclone))

gcc/testsuite/gcc.dg/ira-shrinkwrap-prep-2.c

-/* { dg-do compile { target { { x86_64-*-* && lp64 } || { { powerpc*-*-* && lp64 } || arm_nothumb } } } } */
+/* { dg-do compile { target { { x86_64-*-* && lp64 } || { { powerpc*-*-* && lp64 } || { arm_nothumb || { aarch64*-*-* && lp64 } } } } } } */
 /* { dg-options "-O3 -fdump-rtl-ira -fdump-rtl-pro_and_epilogue -fno-use-caller-save"  } */
 
 long __attribute__((noinline, noclone))

gcc/testsuite/gcc.dg/pr10474.c

-/* { dg-do compile { target { { x86_64-*-* && lp64 } || { { powerpc*-*-* && lp64 } || arm_nothumb } } } } */
+/* { dg-do compile { target { { x86_64-*-* && lp64 } || { { powerpc*-*-* && lp64 } || { arm_nothumb || { aarch64*-*-* && lp64 } } } } } } */
 /* { dg-options "-O3 -fdump-rtl-pro_and_epilogue"  } */
 
 void f(int *i)