cse.c (cse_insn): Set "cse_jumps_altered" when collapsing a switch statement into an...

        * cse.c (cse_insn): Set "cse_jumps_altered" when collapsing
        a switch statement into an unconditional jump.
        * toplev.c (rest_of_compilation): Rerun jump_optimize
        before the second CSE pass.

From-SVN: r6305

2 files changed, 5 insertions, 0 deletions

diff --git a/gcc/cse.c b/gcc/cse.c
index 507cef6..2d326ce 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -6447,6 +6447,7 @@ cse_insn (insn, in_libcall_block)
 		trial = gen_rtx (LABEL_REF, Pmode, get_label_after (trial));
 
 	      SET_SRC (sets[i].rtl) = trial;
+ 	      cse_jumps_altered = 1;
 	      break;
 	    }
 	   
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 10d4f89..9031fee 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -2559,7 +2559,11 @@ rest_of_compilation (decl)
 
   if (optimize > 0 && flag_rerun_cse_after_loop)
     {
+      /* Running another jump optimization pass before the second
+	 cse pass sometimes simplifies the RTL enough to allow
+	 the second CSE pass to do a better job.  */
       TIMEVAR (cse2_time, reg_scan (insns, max_reg_num (), 0));
+      TIMEVAR (jump_time, jump_optimize (insns, 0, 0, 1));
 
       TIMEVAR (cse2_time, tem = cse_main (insns, max_reg_num (),
 					  1, cse2_dump_file));