[Bug rtl-optimization/17513] New: ICE: verify_flow_info failed after gcse

[Bug rtl-optimization/17513] New: ICE: verify_flow_info failed after gcse

[steven at gcc dot gnu dot org]

$ gcc --version 
gcc (GCC) 4.0.0 20040915 (experimental)  
Copyright (C) 2004 Free Software Foundation, Inc. 
This is free software; see the source for copying conditions.  There is NO 
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
 
$ cat t.c 
typedef unsigned char uint8; 
typedef unsigned int uint32; 
 
uint32 marker = 0; 
uint8 *buff = 0; 
uint32 bsize = 0; 
 
extern int foo (void); 
 
uint32 
bar (void) 
{ 
  int len, d; 
 
  for (;;) 
    { 
      if (foo () == 0) 
        return (0); 
 
      switch (marker) 
        { 
        case 0xfe: 
          { 
            len |= (*buff++); 
            bsize -= 2; 
 
            while (len > 0) 
              { 
                d = *buff++; 
                len--; 
              } 
          } 
          break; 
        default: 
          break; 
        } 
    } 
} 
 
$ gcc -O2 t.c 
t.c: In function `bar': 
t.c:38: error: Wrong amount of branch edges after unconditional jump 0 
t.c:38: internal compiler error: verify_flow_info failed 
 
Happens on at least amd64

-- 
           Summary: ICE: verify_flow_info failed after gcse
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P2
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: steven at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17513

[Bug rtl-optimization/17513] ICE: verify_flow_info failed after gcse

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-09-16 08:06 -------
: Search converges between 2004-06-18-trunk (#468) and 2004-06-20-trunk 
(#469). 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17513

[Bug rtl-optimization/17513] ICE: verify_flow_info failed after gcse

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-09-16 08:07 -------
Confirmed by me on amd64 and by phil via his regression tester on i686. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-09-16 08:07:04
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17513

[Bug rtl-optimization/17513] [4.0 Regression] ICE: verify_flow_info failed after gcse

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |critical
            Summary|ICE: verify_flow_info failed|[4.0 Regression] ICE:
                   |after gcse                  |verify_flow_info failed
                   |                            |after gcse
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17513

[Bug rtl-optimization/17513] [4.0 Regression] ICE: verify_flow_info failed after gcse

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-09-16 08:49 -------
Probably need a patch like this,  
  
Index: cfgexpand.c  
===================================================================  
RCS file: /cvs/gcc/gcc/gcc/cfgexpand.c,v  
retrieving revision 2.23  
diff -c -3 -p -r2.23 cfgexpand.c  
*** cfgexpand.c 11 Sep 2004 20:07:11 -0000      2.23  
--- cfgexpand.c 16 Sep 2004 08:48:55 -0000  
*************** static basic_block  
*** 1082,1092 ****  
  construct_init_block (void)  
  {  
    basic_block init_block, first_block;  
!   edge e;  
  
!   for (e = ENTRY_BLOCK_PTR->succ; e; e = e->succ_next)  
!     if (e->dest == ENTRY_BLOCK_PTR->next_bb)  
!       break;  
  
    init_block = create_basic_block (NEXT_INSN (get_insns ()),  
                                   get_last_insn (),  
--- 1082,1102 ----  
  construct_init_block (void)  
  {  
    basic_block init_block, first_block;  
!   edge e = NULL, e2;  
  
!   for (e2 = ENTRY_BLOCK_PTR->succ; e2; e2 = e2->succ_next)  
!     {  
!       /* Clear EDGE_EXECUTABLE.  This flag is never used in the backend.  
!  
!        For all other blocks this edge flag is cleared while expanding  
!        a basic block in expand_gimple_basic_block, but there we never  
!        looked at the successors of the entry block.  
!        This caused PR17513.  */  
!       e2->flags &= ~EDGE_EXECUTABLE;  
!  
!       if (e2->dest == ENTRY_BLOCK_PTR->next_bb)  
!       e = e2;  
!     }  
  
    init_block = create_basic_block (NEXT_INSN (get_insns ()),  
                                   get_last_insn (),  

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17513

[Bug rtl-optimization/17513] [4.0 Regression] ICE: verify_flow_info failed after gcse

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-09-16 09:11 -------
http://gcc.gnu.org/ml/gcc-patches/2004-09/msg01660.html 

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17513

[Bug rtl-optimization/17513] [4.0 Regression] ICE: verify_flow_info failed after gcse

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2004-09-17 06:24 -------
Subject: Bug 17513

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	steven@gcc.gnu.org	2004-09-17 06:23:54

Modified files:
	gcc            : ChangeLog cfgexpand.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg: 20040916-1.c 

Log message:
	PR tree-optimization/17513
	* cfgexpand.c (construct_init_block): Clear EDGE_EXECUTABLE
	for successors of the entry block.
	
	* gcc.dg/20040916-1.c: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.5488&r2=2.5489
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cfgexpand.c.diff?cvsroot=gcc&r1=2.23&r2=2.24
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.4302&r2=1.4303
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/20040916-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17513

[Bug rtl-optimization/17513] [4.0 Regression] ICE: verify_flow_info failed after gcse

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2004-09-17 06:26 -------
. 

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17513