[PATCH 1/3] Replace MD_REDIRECT_BRANCH with TARGET_CAN_FOLLOW_JUMP

[Kaz Kojima <kkojima at rr dot iij4u dot or dot jp>]

This is an updated patch of the patch proposed by Joern

https://gcc.gnu.org/ml/gcc-patches/2013-04/msg01332.html

which replaces MD_REDIRECT_BRANCH of which SH is the last user
with TARGET_CAN_FOLLOW_JUMP.

--
2015-01-27  Joern Rennecke  <joern.rennecke@embecosm.com>
	    Kaz Kojima  <kkojima@gcc.gnu.org>

	PR target/64761
	* config/sh/sh-protos.h (sh_can_redirect_branch): Don't declare.
	* config/sh/sh.c (TARGET_CAN_FOLLOW_JUMP): Redefine.
	(sh_can_redirect_branch): Rename to ...
	(sh_can_follow_jump): ... this.  Constify argument types.
	* config/sh/sh.h (MD_CAN_REDIRECT_BRANCH): Don't define.
	* doc/tm.texi.in (MD_CAN_REDIRECT_BRANCH): Remove documentation.
	* reorg.c (steal_delay_list_from_target): Use targetm.can_follow_jump.
	* doc/tm.texi: Regenerate.

diff --git a/config/sh/sh-protos.h b/config/sh/sh-protos.h
index bc2b3b3..a5ffd9c 100644
--- a/config/sh/sh-protos.h
+++ b/config/sh/sh-protos.h
@@ -148,7 +148,6 @@ extern enum tls_model tls_symbolic_operand (rtx, machine_mode);
 extern bool system_reg_operand (rtx, machine_mode);
 extern bool reg_unused_after (rtx, rtx_insn *);
 extern int sh_insn_length_adjustment (rtx_insn *);
-extern bool sh_can_redirect_branch (rtx_insn *, rtx_insn *);
 extern void sh_expand_unop_v2sf (enum rtx_code, rtx, rtx);
 extern void sh_expand_binop_v2sf (enum rtx_code, rtx, rtx, rtx);
 extern bool sh_expand_t_scc (rtx *);
diff --git a/config/sh/sh.c b/config/sh/sh.c
index bde95f6..886ffc3 100644
--- a/config/sh/sh.c
+++ b/config/sh/sh.c
@@ -277,6 +277,7 @@ static int sh_variable_issue (FILE *, int, rtx_insn *, int);
 static bool sh_function_ok_for_sibcall (tree, tree);
 
 static bool sh_cannot_modify_jumps_p (void);
+static bool sh_can_follow_jump (const rtx_insn *, const rtx_insn *);
 static reg_class_t sh_target_reg_class (void);
 static bool sh_optimize_target_register_callee_saved (bool);
 static bool sh_ms_bitfield_layout_p (const_tree);
@@ -510,6 +511,8 @@ static const struct attribute_spec sh_attribute_table[] =
 
 #undef TARGET_CANNOT_MODIFY_JUMPS_P
 #define TARGET_CANNOT_MODIFY_JUMPS_P sh_cannot_modify_jumps_p
+#undef TARGET_CAN_FOLLOW_JUMP
+#define TARGET_CAN_FOLLOW_JUMP sh_can_follow_jump
 #undef TARGET_BRANCH_TARGET_REGISTER_CLASS
 #define TARGET_BRANCH_TARGET_REGISTER_CLASS sh_target_reg_class
 #undef TARGET_BRANCH_TARGET_REGISTER_CALLEE_SAVED
@@ -10744,8 +10747,8 @@ mark_constant_pool_use (rtx x)
 /* Return true if it's possible to redirect BRANCH1 to the destination
    of an unconditional jump BRANCH2.  We only want to do this if the
    resulting branch will have a short displacement.  */
-bool
-sh_can_redirect_branch (rtx_insn *branch1, rtx_insn *branch2)
+static bool
+sh_can_follow_jump (const rtx_insn *branch1, const rtx_insn *branch2)
 {
   if (flag_expensive_optimizations && simplejump_p (branch2))
     {
diff --git a/config/sh/sh.h b/config/sh/sh.h
index 2de7381..a9b7fa0 100644
--- a/config/sh/sh.h
+++ b/config/sh/sh.h
@@ -2245,9 +2245,6 @@ extern int current_function_interrupt;
 #define EPILOGUE_USES(REGNO) ((TARGET_SH2E || TARGET_SH4) \
 			      && (REGNO) == FPSCR_REG)
 
-#define MD_CAN_REDIRECT_BRANCH(INSN, SEQ) \
-  sh_can_redirect_branch ((INSN), (SEQ))
-
 #define DWARF_FRAME_RETURN_COLUMN \
   (TARGET_SH5 ? DWARF_FRAME_REGNUM (PR_MEDIA_REG) : DWARF_FRAME_REGNUM (PR_REG))
 
diff --git a/doc/tm.texi.in b/doc/tm.texi.in
index 0cee98a..edad99c 100644
--- a/doc/tm.texi.in
+++ b/doc/tm.texi.in
@@ -7982,17 +7982,6 @@ to by @var{ce_info}.
 
 @hook TARGET_LEGITIMATE_COMBINED_INSN
 
-@defmac MD_CAN_REDIRECT_BRANCH (@var{branch1}, @var{branch2})
-
-Take a branch insn in @var{branch1} and another in @var{branch2}.
-Return true if redirecting @var{branch1} to the destination of
-@var{branch2} is possible.
-
-On some targets, branches may have a limited range.  Optimizing the
-filling of delay slots can result in branches being redirected, and this
-may in turn cause a branch offset to overflow.
-@end defmac
-
 @hook TARGET_CAN_FOLLOW_JUMP
 
 @hook TARGET_COMMUTATIVE_P
diff --git a/reorg.c b/reorg.c
index 05b8444..326fa53 100644
--- a/reorg.c
+++ b/reorg.c
@@ -1156,13 +1156,11 @@ steal_delay_list_from_target (rtx_insn *insn, rtx condition, rtx_sequence *seq,
       || ! single_set (seq->insn (0)))
     return delay_list;
 
-#ifdef MD_CAN_REDIRECT_BRANCH
   /* On some targets, branches with delay slots can have a limited
      displacement.  Give the back end a chance to tell us we can't do
      this.  */
-  if (! MD_CAN_REDIRECT_BRANCH (insn, seq->insn (0)))
+  if (! targetm.can_follow_jump (insn, seq->insn (0)))
     return delay_list;
-#endif
 
   redundant = XALLOCAVEC (bool, XVECLEN (seq, 0));
   for (i = 1; i < seq->len (); i++)