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Re: Ping: patch to remove the old RA


H.J. Lu wrote:
On Thu, Jan 29, 2009 at 1:06 PM, Vladimir Makarov <vmakarov@redhat.com> wrote:
H.J. Lu wrote:
On Thu, Jan 29, 2009 at 12:32 PM, H.J. Lu <hjl.tools@gmail.com> wrote:

No, regmove for IRA does the same as before the patch.



Revision 143757 changed regmove.c:

     /* We need fewer optimizations for IRA.  */
-      if ((! flag_regmove || flag_ira) && pass >=
flag_expensive_optimizations)
+      if (! flag_regmove && pass >= flag_expensive_optimizations)
      goto done;

Since flag_regmove is 1 at -O2, remove  flag_ira does change IRA code
generation.


FWIW, I am not against this change since it does fixes PR 37364.
I am running SPEC CPU 2K/2006 with revision 143757 on ia32
and Intel64.


I am not against it too :) Actually it was my intention to do this
originally. No harm to do some optimizations twice. I only wanted to
remove optimizations which is done by IRA. But it looks that I did a
stupid mistake and switched the second pass off for optimizations which
should work with IRA.

Shouldn't we remove the obsolete comments:


Index: regmove.c
===================================================================
--- regmove.c	(revision 143757)
+++ regmove.c	(working copy)
@@ -1089,7 +1089,6 @@ regmove_optimize (rtx f, int nregs)

   for (pass = 0; pass <= 2; pass++)
     {
-      /* We need fewer optimizations for IRA.  */
       if (! flag_regmove && pass >= flag_expensive_optimizations)
 	goto done;


Yes, that is comment obsolete now. So it can be removed.
I think the current code should stay unless there is no big performance

^^^^


I assume you meant "unless there is big performance regressions."

Yes, you are right. I've made a typo.


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