[binutils-gdb] gas: xtensa: reuse trampoline placement code

[Max Filippov <jcmvbkbc at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=76a493ab99d9276180db6e791f95d1d6d86d2954

commit 76a493ab99d9276180db6e791f95d1d6d86d2954
Author: Max Filippov <jcmvbkbc@gmail.com>
Date:   Mon Nov 13 00:42:43 2017 -0800

    gas: xtensa: reuse trampoline placement code
    
    There's almost exact copy of the trampoline placement code in the
    search_trampolines function that is used for jumps generated for relaxed
    branch instructions. Get rid of the duplication and reuse
    xg_find_best_trampoline function for that.
    
    gas/
    2017-11-27  Max Filippov  <jcmvbkbc@gmail.com>
    
    	* config/tc-xtensa.c (search_trampolines, get_best_trampoline):
    	Remove definitions.
    	(xg_find_best_trampoline_for_tinsn): New function.
    	(relax_frag_immed): Replace call to get_best_trampoline with a
    	call to xg_find_best_trampoline_for_tinsn.
    	* testsuite/gas/xtensa/trampoline.d: Adjust absolute addresses
    	as the placement of trampolines for relaxed branches has been
    	changed.

Diff:
---
 gas/ChangeLog                         | 11 ++++
 gas/config/tc-xtensa.c                | 97 ++++-------------------------------
 gas/testsuite/gas/xtensa/trampoline.d |  6 +--
 3 files changed, 23 insertions(+), 91 deletions(-)

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 24c1eb0..c129941 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,5 +1,16 @@
 2017-11-27  Max Filippov  <jcmvbkbc@gmail.com>
 
+	* config/tc-xtensa.c (search_trampolines, get_best_trampoline):
+	Remove definitions.
+	(xg_find_best_trampoline_for_tinsn): New function.
+	(relax_frag_immed): Replace call to get_best_trampoline with a
+	call to xg_find_best_trampoline_for_tinsn.
+	* testsuite/gas/xtensa/trampoline.d: Adjust absolute addresses
+	as the placement of trampolines for relaxed branches has been
+	changed.
+
+2017-11-27  Max Filippov  <jcmvbkbc@gmail.com>
+
 	* config/tc-xtensa.c (trampoline_index): New structure.
 	(trampoline_seg): Replace trampoline list with trampoline index.
 	(xg_find_trampoline, xg_add_trampoline_to_index)
diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
index 7d8b62b..b507d44 100644
--- a/gas/config/tc-xtensa.c
+++ b/gas/config/tc-xtensa.c
@@ -9806,99 +9806,20 @@ bytes_to_stretch (fragS *this_frag,
 
 
 static fragS *
-search_trampolines (TInsn *tinsn, fragS *fragP, bfd_boolean unreachable_only)
+xg_find_best_trampoline_for_tinsn (TInsn *tinsn, fragS *fragP)
 {
+  symbolS *sym = tinsn->tok[0].X_add_symbol;
+  addressT source = fragP->fr_address;
+  addressT target = S_GET_VALUE (sym) + tinsn->tok[0].X_add_number;
   struct trampoline_seg *ts = find_trampoline_seg (now_seg);
-  fragS *tf = NULL;
   size_t i;
-  fragS *best_tf = NULL;
-  offsetT best_delta = 0;
-  offsetT best_addr = 0;
-  symbolS *sym = tinsn->tok[0].X_add_symbol;
-  offsetT target = S_GET_VALUE (sym) + tinsn->tok[0].X_add_number;
-  offsetT addr = fragP->fr_address;
-  offsetT lower = (addr < target) ? addr : target;
-  offsetT upper = (addr > target) ? addr : target;
-  offsetT delta = upper - lower;
-  offsetT midpoint = lower + delta / 2;
-  offsetT this_delta = -1;
-  offsetT this_addr = -1;
-
-  if (!ts)
-    return NULL;
-
-  if (delta > 2 * J_RANGE)
-    {
-      /* One trampoline won't do; we need multiple.
-	 Choose the farthest trampoline that's still in range of the original
-	 and let a later pass finish the job.  */
-      for (i = 0; i < ts->index.n_entries; ++i)
-	{
-	  tf = ts->index.entry[i];
-	  this_addr = tf->fr_address + tf->fr_fix;
-	  if (upper == addr)
-	    {
-	      /* Backward jump.  */
-	      if (addr - this_addr < J_RANGE)
-		break;
-	    }
-	  else if (i + 1 < ts->index.n_entries)
-	    {
-	      /* Forward jump.  */
-	      fragS *next = ts->index.entry[i + 1];
-	      offsetT next_addr = next->fr_address + next->fr_fix;
-
-	      if (next_addr - addr > J_RANGE)
-		break;
-	    }
-	  else
-	    {
-	      break;
-	    }
-	}
-      if (i < ts->index.n_entries &&
-	  labs (addr - this_addr) < J_RANGE)
-	return tf;
-
-      return NULL;
-    }
-
-  for (i = 0; i < ts->index.n_entries; ++i)
-    {
-      tf = ts->index.entry[i];
-      this_addr = tf->fr_address + tf->fr_fix;
-      this_delta = labs (this_addr - midpoint);
-      if (unreachable_only && tf->tc_frag_data.needs_jump_around)
-	continue;
-      if (!best_tf || this_delta < best_delta)
-        {
-	  best_tf = tf;
-	  best_delta = this_delta;
-	  best_addr = this_addr;
-        }
-    }
-
-  if (best_tf &&
-      best_delta < J_RANGE &&
-      labs(best_addr - lower) < J_RANGE &&
-      labs(best_addr - upper) < J_RANGE)
-    return best_tf;
-
-  return NULL; /* No suitable trampoline found.  */
-}
-
 
-static fragS *
-get_best_trampoline (TInsn *tinsn, fragS *fragP)
-{
-  fragS *tf = NULL;
-
-  tf = search_trampolines (tinsn, fragP, TRUE); /* Try unreachable first.  */
+  if (!ts || !ts->index.n_entries)
+    return NULL;
 
-  if (tf == NULL)
-    tf = search_trampolines (tinsn, fragP, FALSE); /* Try ones needing a jump-around, too.  */
+  i = xg_find_best_trampoline (&ts->index, source, target);
 
-  return tf;
+  return ts->index.entry[i];
 }
 
 
@@ -10154,7 +10075,7 @@ relax_frag_immed (segT segP,
 
       if (!xg_symbolic_immeds_fit (jinsn, segP, fragP, fragP->fr_offset, total_text_diff))
 	{
-	  fragS *tf = get_best_trampoline (jinsn, fragP);
+	  fragS *tf = xg_find_best_trampoline_for_tinsn (jinsn, fragP);
 
 	  if (tf)
 	    {
diff --git a/gas/testsuite/gas/xtensa/trampoline.d b/gas/testsuite/gas/xtensa/trampoline.d
index c0bac6d..f9aa5d9 100644
--- a/gas/testsuite/gas/xtensa/trampoline.d
+++ b/gas/testsuite/gas/xtensa/trampoline.d
@@ -23,11 +23,11 @@
 #...
 .*49404:.*j.0x49404
 .*49407:.*beqz.n.a2,.0x4940c
-.*49409:.*j.0x693ce
+.*49409:.*j.0x61aa2
 #...
-.*693ce:.*j.0x7ddd1
+.*61aa2:.*j.0x7a13b
 #...
-.*7ddd1:.*j.0x927f5
+.*7a13b:.*j.0x927f5
 #...
 .*927f5:.*j.0x927f5
 #...