[committed] Use target-insns.def for eh_return

[committed] Use target-insns.def for eh_return

[Richard Sandiford]

The thread_prologue_and_epilogue_insns code that used to be protected
by #ifdef HAVE_eh_return is unconditionally correct and isn't on any
kind of hot path (it's only run once per function).

Bootstrapped & regression-tested on x86_64-linux-gnu and aarch64-linux-gnu.
Also tested via config-list.mk.  Committed as preapproved.

Thanks,
Richard


gcc/
	* target-insns.def (eh_return): New targetm instruction pattern.
	* except.c (expand_eh_return): Use it instead of HAVE_*/gen_*
	interface.
	* function.c (thread_prologue_and_epilogue_insns): Remove
	preprocessor condition.

Index: gcc/target-insns.def
===================================================================
--- gcc/target-insns.def	2015-06-28 12:00:27.698196372 +0100
+++ gcc/target-insns.def	2015-06-28 12:00:31.448043556 +0100
@@ -39,6 +39,7 @@ DEF_TARGET_INSN (check_stack, (rtx x0))
 DEF_TARGET_INSN (clear_cache, (rtx x0, rtx x1))
 DEF_TARGET_INSN (doloop_begin, (rtx x0, rtx x1))
 DEF_TARGET_INSN (doloop_end, (rtx x0, rtx x1))
+DEF_TARGET_INSN (eh_return, (rtx x0))
 DEF_TARGET_INSN (epilogue, (void))
 DEF_TARGET_INSN (exception_receiver, (void))
 DEF_TARGET_INSN (extv, (rtx x0, rtx x1, rtx x2, rtx x3))
Index: gcc/except.c
===================================================================
--- gcc/except.c	2015-06-28 12:00:27.698196372 +0100
+++ gcc/except.c	2015-06-28 12:00:31.449043515 +0100
@@ -2271,11 +2271,9 @@ expand_eh_return (void)
   emit_move_insn (EH_RETURN_STACKADJ_RTX, crtl->eh.ehr_stackadj);
 #endif
 
-#ifdef HAVE_eh_return
-  if (HAVE_eh_return)
-    emit_insn (gen_eh_return (crtl->eh.ehr_handler));
+  if (targetm.have_eh_return ())
+    emit_insn (targetm.gen_eh_return (crtl->eh.ehr_handler));
   else
-#endif
     {
 #ifdef EH_RETURN_HANDLER_RTX
       emit_move_insn (EH_RETURN_HANDLER_RTX, crtl->eh.ehr_handler);
Index: gcc/function.c
===================================================================
--- gcc/function.c	2015-06-28 12:00:27.698196372 +0100
+++ gcc/function.c	2015-06-28 12:00:31.447043596 +0100
@@ -5963,7 +5963,6 @@ thread_prologue_and_epilogue_insns (void
      uses the flag in the meantime.  */
   epilogue_completed = 1;
 
-#ifdef HAVE_eh_return
   /* Find non-fallthru edges that end with EH_RETURN instructions.  On
      some targets, these get split to a special version of the epilogue
      code.  In order to be able to properly annotate these with unwind
@@ -5987,7 +5986,6 @@ thread_prologue_and_epilogue_insns (void
       record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
       emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
     }
-#endif
 
   /* If nothing falls through into the exit block, we don't need an
      epilogue.  */