[Bug rtl-optimization/17625] New: ICE on legal (doloop creates shared RTL)

[Bug rtl-optimization/17625] New: ICE on legal (doloop creates shared RTL)

[dalej at apple dot com]

The following small program crashes as shown.  This is 64-bit specific, and Darwin 64-bit is
not really all there yet, as you will see if you apply the suggested patch: another Darwin-specific
bug is lurking behind.  However this bug is not Darwin specific, and can probably be seen
on other PPC64 OSs.  The problem is that the doloop optimizer is creating shared RTL (the
path to the crash is convoluted; I can explain if necessary.)  The patch at bottom works, but
I don't know if this is really the best place to fix it.

gcc -Os -m64 3811724.c
3811724.c: In function 'acl_create_entry_np':
3811724.c:23: internal compiler error: in schedule_insns, at sched-rgn.c:2708
Please submit a full bug report,

struct _acl {
 unsigned int a_entries;
 int a_ace[128];
};
extern int * __error(void);
int acl_create_entry_np(struct _acl **acl_p, int *dummy, int index)
{
 struct _acl *ap = *acl_p;
 int i;
 if (ap->a_entries >= 128) {
  (*__error()) = 12;
  return(-1);
 }
 for (i = ap->a_entries; i > index; i--)
  ap->a_ace[i] = ap->a_ace[i - 1];
 return(0);
}

Index: loop-doloop.c
===============================================================
====
RCS file: /cvs/gcc/gcc/gcc/loop-doloop.c,v
retrieving revision 2.7
diff -u -d -b -w -p -r2.7 loop-doloop.c
--- loop-doloop.c       10 Sep 2004 11:02:24 -0000      2.7
+++ loop-doloop.c       23 Sep 2004 00:53:43 -0000
@@ -333,7 +333,7 @@ doloop_modify (struct loop *loop, struct
     }
 
   if (increment_count)
-    count = simplify_gen_binary (PLUS, desc->mode, count, const1_rtx);
+    count = simplify_gen_binary (PLUS, desc->mode, copy_rtx (count), const1_rtx);
 
   /* Insert initialization of the count register into the loop header.  */
   start_sequence ();
@@ -345,7 +345,7 @@ doloop_modify (struct loop *loop, struct
 
   if (desc->noloop_assumptions)
     {
-      rtx ass = desc->noloop_assumptions;
+      rtx ass = copy_rtx (desc->noloop_assumptions);
       basic_block preheader = loop_preheader_edge (loop)->src;
       basic_block set_zero
              = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);

-- 
           Summary: ICE on legal (doloop creates shared RTL)
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dalej at apple dot com
                CC: gcc-bugs at gcc dot gnu dot org,rakdver at atrey dot
                    karlin dot mff dot cuni dot cz
 GCC build triplet: powerpc-apple-darwin7.3.0
  GCC host triplet: powerpc-darwin-darwin7.3.0
GCC target triplet: powerpc-apple-darwin7.3.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17625

[Bug rtl-optimization/17625] [4.0 Regression] ICE on legal (doloop creates shared RTL)

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-23 01:11 -------
Confirmed, I almost think this is a regression even though 64bit mode is new for 4.0.0.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |ice-on-valid-code
   Last reconfirmed|0000-00-00 00:00:00         |2004-09-23 01:11:27
               date|                            |
            Summary|ICE on legal (doloop creates|[4.0 Regression] ICE on
                   |shared RTL)                 |legal (doloop creates shared
                   |                            |RTL)
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17625

[Bug rtl-optimization/17625] [4.0 Regression] ICE on legal (doloop creates shared RTL)

[rakdver at gcc dot gnu dot org]

------- Additional Comments From rakdver at gcc dot gnu dot org  2004-09-23 10:39 -------
The fix should be basically OK, except that it would be a bit safer to
unshare the count earlier; I am testing this patch.

Index: loop-doloop.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/loop-doloop.c,v
retrieving revision 2.7
diff -c -3 -p -r2.7 loop-doloop.c
*** loop-doloop.c       10 Sep 2004 11:02:24 -0000      2.7
--- loop-doloop.c       23 Sep 2004 10:37:00 -0000
*************** doloop_modify (struct loop *loop, struct
*** 292,298 ****
    if (GET_CODE (counter_reg) == PLUS)
      counter_reg = XEXP (counter_reg, 0);

!   count = desc->niter_expr;
    increment_count = false;
    switch (GET_CODE (condition))
      {
--- 292,298 ----
    if (GET_CODE (counter_reg) == PLUS)
      counter_reg = XEXP (counter_reg, 0);

!   count = copy_rtx (desc->niter_expr);
    increment_count = false;
    switch (GET_CODE (condition))
      {
*************** doloop_modify (struct loop *loop, struct
*** 345,351 ****

    if (desc->noloop_assumptions)
      {
!       rtx ass = desc->noloop_assumptions;
        basic_block preheader = loop_preheader_edge (loop)->src;
        basic_block set_zero
              = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);
--- 345,351 ----

    if (desc->noloop_assumptions)
      {
!       rtx ass = copy_rtx (desc->noloop_assumptions);
        basic_block preheader = loop_preheader_edge (loop)->src;
        basic_block set_zero
              = loop_split_edge_with (loop_preheader_edge (loop), NULL_RTX);


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17625

[Bug rtl-optimization/17625] [4.0 Regression] ICE on legal (doloop creates shared RTL)

[rakdver at gcc dot gnu dot org]

------- Additional Comments From rakdver at gcc dot gnu dot org  2004-09-24 08:29 -------
Patch:

http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02517.html

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17625

[Bug rtl-optimization/17625] [4.0 Regression] ICE on legal (doloop creates shared RTL)

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-09-24 14:36 -------
Subject: Bug 17625

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	rakdver@gcc.gnu.org	2004-09-24 14:36:29

Modified files:
	gcc            : ChangeLog loop-doloop.c 

Log message:
	PR rtl-optimization/17625
	* loop-doloop.c (doloop_modify): Unshare rtl before emitting it.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.5600&r2=2.5601
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop-doloop.c.diff?cvsroot=gcc&r1=2.7&r2=2.8



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17625

[Bug rtl-optimization/17625] [4.0 Regression] ICE on legal (doloop creates shared RTL)

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-24 14:52 -------
Fixed.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17625

[Bug rtl-optimization/17625] [4.0 Regression] ICE on legal (doloop creates shared RTL)

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-09-24 17:06 -------
Subject: Bug 17625

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	apple-ppc-branch
Changes by:	dalej@gcc.gnu.org	2004-09-24 17:06:36

Modified files:
	gcc            : ChangeLog.apple-ppc loop-doloop.c 

Log message:
	Radar 3811274 / PR 17625.  Roll in fix from FSF.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.apple-ppc.diff?cvsroot=gcc&only_with_tag=apple-ppc-branch&r1=1.1.2.149&r2=1.1.2.150
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop-doloop.c.diff?cvsroot=gcc&only_with_tag=apple-ppc-branch&r1=2.2.10.7&r2=2.2.10.8



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17625