[Bug middle-end/25662] New: [4.0/4.1/4.2 Regression] Unrecognizable insn with -O on PPC

[Bug middle-end/25662] New: [4.0/4.1/4.2 Regression] Unrecognizable insn with -O on PPC

[halcy0n at gentoo dot org]

The following testcase works on PPC with gcc-3.4, but fails with >=4.0.

__extension__ typedef unsigned long long guint64;
typedef int gint;
typedef gint gboolean;

typedef struct
{ 
  guint64 rte;
} mainwindow;
mainwindow *mainw;

static int bg_gen_to_start;

gboolean weed_playback_gen_start (void)
{ 
  bg_gen_to_start = -1;
  if (mainw->rte & (((guint64) 1) << bg_gen_to_start))
    mainw->rte ^= (((guint64) 1) << bg_gen_to_start);
}

The error with mainline (only reproducible with atleast -O):

test.c: In function 'weed_playback_gen_start':
test.c:18: error: unrecognizable insn:
(insn 37 36 39 2 (set (subreg:SI (reg:DI 119 [ D.1305 ]) 4)
        (ashift:SI (const_int 1 [0x1])
            (const_int -1 [0xffffffffffffffff]))) -1 (nil)
    (nil))
test.c:18: internal compiler error: in extract_insn, at recog.c:2084


-- 
           Summary: [4.0/4.1/4.2 Regression] Unrecognizable insn with -O on
                    PPC
           Product: gcc
           Version: 4.0.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: halcy0n at gentoo dot org
 GCC build triplet: powerpc-unknown-linux-gnu
  GCC host triplet: powerpc-unknown-linux-gnu
GCC target triplet: powerpc-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2006-01-04 14:37 -------
This works on the mainline as of today but failed with 4.2.0 20051219.

Confirmed.  Though I should note this is really weird as DOM is messing up in
that version of GCC and we still have 1 << -1 which is not being folded.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
           Severity|normal                      |critical
          Component|middle-end                  |target
      Known to fail|4.0.3 4.1.0 4.2.0           |4.0.3 4.1.0
      Known to work|3.4.5                       |3.4.5 4.2.0
            Summary|[4.0/4.1/4.2 Regression]    |[4.0/4.1 Regression]
                   |Unrecognizable insn with -O |Unrecognizable insn with -O
                   |on PPC                      |on PPC
   Target Milestone|---                         |4.0.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[jakub at gcc dot gnu dot org]

------- Comment #2 from jakub at gcc dot gnu dot org  2006-01-05 08:40 -------
Note that the code has undefined behaviour.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[ian at airs dot com]

------- Comment #3 from ian at airs dot com  2006-01-06 19:05 -------
I think this is a bug in simplify_expand_binop (adding Richard Sandiford to the
CC since he introduced that function).  Currently when simplify_expand_binop is
given two constants, it calls simplify_gen_binary.  When the operation does not
simplify, that will wind up returning RTL which may not satisfy the instruction
predicates.

I think it should call simplify_binary_operation instead.  If that fails, it
should call expand_binop as usual.

I will attach a sample, untested, patch.


-- 

ian at airs dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |richard at codesourcery dot
                   |                            |com, ian at airs dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[ian at airs dot com]

------- Comment #4 from ian at airs dot com  2006-01-06 19:06 -------
Created an attachment (id=10590)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=10590&action=view)
Sample untested patch


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[dje at gcc dot gnu dot org]

------- Comment #5 from dje at gcc dot gnu dot org  2006-01-06 20:18 -------
The patched compiler does build and does fix the testcase.


-- 

dje at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dje at gcc dot gnu dot org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-01-06 20:18:53
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[halcy0n at gentoo dot org]

------- Comment #6 from halcy0n at gentoo dot org  2006-01-06 20:54 -------
I can confirm it fixes it on my box as well.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[dje at gcc dot gnu dot org]

------- Comment #7 from dje at gcc dot gnu dot org  2006-01-07 22:23 -------
Subject: Bug 25662

Author: dje
Date: Sat Jan  7 22:23:27 2006
New Revision: 109456

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=109456
Log:
2005-01-07  Ian Lance Taylor  <ian@airs.com>
            David Edelsohn  <edelsohn@gnu.org>

        PR rtl-optimization/25662
        * optabs.c (simplify_expand_binop): Use simplify_binary_operation
        for constant operands instead of simplify_gen_binary.
        * simplify-rtx.c (simplify_gen_binary): Swap commutative operands
        after trying simplify_binary_operation

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/optabs.c
    trunk/gcc/simplify-rtx.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[dje at gcc dot gnu dot org]

------- Comment #8 from dje at gcc dot gnu dot org  2006-01-08 20:54 -------
Subject: Bug 25662

Author: dje
Date: Sun Jan  8 20:54:28 2006
New Revision: 109476

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=109476
Log:
2006-01-08  Ian Lance Taylor  <ian@airs.com>
            David Edelsohn  <edelsohn@gnu.org>

        PR rtl-optimization/25662
        * optabs.c (simplify_expand_binop): Use simplify_binary_operation
        for constant operands instead of simplify_gen_binary.

Modified:
    branches/gcc-4_1-branch/gcc/ChangeLog
    branches/gcc-4_1-branch/gcc/optabs.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[dje at gcc dot gnu dot org]

------- Comment #9 from dje at gcc dot gnu dot org  2006-01-08 20:55 -------
Subject: Bug 25662

Author: dje
Date: Sun Jan  8 20:55:39 2006
New Revision: 109477

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=109477
Log:
2006-01-08  Ian Lance Taylor  <ian@airs.com>
            David Edelsohn  <edelsohn@gnu.org>

        PR rtl-optimization/25662
        * optabs.c (simplify_expand_binop): Use simplify_binary_operation
        for constant operands instead of simplify_gen_binary.

Modified:
    branches/gcc-4_0-branch/gcc/ChangeLog
    branches/gcc-4_0-branch/gcc/optabs.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662

[Bug target/25662] [4.0/4.1 Regression] Unrecognizable insn with -O on PPC

[dje at gcc dot gnu dot org]

------- Comment #10 from dje at gcc dot gnu dot org  2006-01-09 02:19 -------
Fix committed to all mainline, 4.1, 4.0.


-- 

dje at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25662