(jump_optimize): If we reverse "if (foo) bar else break;" and there follows a NOTE_IN...

(jump_optimize): If we reverse "if (foo) bar else break;"
and there follows a NOTE_INSN_LOOP_END, move the note before "bar".

From-SVN: r7557

diff --git a/gcc/jump.c b/gcc/jump.c
index 076f6950b11c98c10f6fd81c33ad1fa9bdbe85ac..2f9621f47f52b6fce8c65147131a5352d9254535 100644 (file)
--- a/gcc/jump.c
+++ b/gcc/jump.c
@@ -1750,6 +1750,7 @@ jump_optimize (f, cross_jump, noop_moves, after_regscan)
                        rtx range2beg = next_active_insn (label1);
                        rtx range1after, range2after;
                        rtx range1before, range2before;
+                       rtx rangenext;
 
                        /* Include in each range any notes before it, to be
                           sure that we get the line number note if any, even
@@ -1783,6 +1784,34 @@ jump_optimize (f, cross_jump, noop_moves, after_regscan)
                        PREV_INSN (range1beg) = range2before;
                        NEXT_INSN (range1end) = range2after;
                        PREV_INSN (range2after) = range1end;
+
+                       /* Check for a loop end note between the end of
+                          range2, and the next code label.  If there is one,
+                          then what we have really seen is
+                          if (foo) break; end_of_loop;
+                          and moved the break sequence outside the loop.
+                          We must move the LOOP_END note to where the
+                          loop really ends now, or we will confuse loop
+                          optimization.  */
+                       for (;range2after != label2; range2after = rangenext)
+                         {
+                           rangenext = NEXT_INSN (range2after);
+                           if (GET_CODE (range2after) == NOTE
+                               && (NOTE_LINE_NUMBER (range2after)
+                                   == NOTE_INSN_LOOP_END))
+                             {
+                               NEXT_INSN (PREV_INSN (range2after))
+                                 = rangenext;
+                               PREV_INSN (rangenext)
+                                 = PREV_INSN (range2after);
+                               PREV_INSN (range2after) 
+                                 = PREV_INSN (range1beg);
+                               NEXT_INSN (range2after) = range1beg;
+                               NEXT_INSN (PREV_INSN (range1beg))
+                                 = range2after;
+                               PREV_INSN (range1beg) = range2after;
+                             }
+                         }
                        changed = 1;
                        continue;
                      }