[Bug target/37878] New: PPC64 ldu command generated with invalid offset

[Bug target/37878] New: PPC64 ldu command generated with invalid offset

[lucier at math dot purdue dot edu]

With this compiler:

[descartes:gcc/objdirs/gambc-v4_1_2] lucier% /pkgs/gcc-4.4.0-64/bin/gcc -v
Using built-in specs.
Target: powerpc64-apple-darwin9.5.0
Configured with: ../../mainline/configure CC='/usr/bin/gcc-4.0 -mcpu=970 -m64'
--disable-werror --build=powerpc64-apple-darwin9.5.0
--host=powerpc64-apple-darwin9.5.0 --target=powerpc64-apple-darwin9.5.0
--with-gmp-include=/sw/include/ --with-gmp-lib=/sw/lib/ppc64
--with-mpfr-include=/sw/include/ --with-mpfr-lib=/sw/lib/ppc64
--prefix=/pkgs/gcc-4.4.0-64 --with-libiconv-prefix=/usr --with-system-zlib
Thread model: posix
gcc version 4.4.0 20081020 (experimental) [trunk revision 141240] (GCC) 

I get this error:

[descartes:gcc/objdirs/gambc-v4_1_2] lucier% /pkgs/gcc-4.4.0-64/bin/gcc
-save-temps -mcpu=970 -m64 -I../include -I. -no-cpp-precomp -Wall -W
-Wno-unused -O1 -fno-math-errno -fschedule-insns2 -fno-trapping-math
-fno-strict-aliasing -fwrapv -fomit-frame-pointer -fPIC -fno-common
-DHAVE_CONFIG_H -D___PRIMAL -D___LIBRARY -c assemtest.i
gcc: unrecognized option '-no-cpp-precomp'
assemtest.s:69:Parameter error: expression must be a multiple of 4 (parameter
2)

The offending assembler command is

        ldu r0,7(r9)

I'll include assemtest.i; the code itself is about 50 lines of
machine-generated C code, plus a lot of declarations so I could get it to
compile separately.


-- 
           Summary: PPC64 ldu command generated with invalid offset
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: lucier at math dot purdue dot edu
 GCC build triplet: powerpc64-apple-darwin9.5.0
  GCC host triplet: powerpc64-apple-darwin9.5.0
GCC target triplet: powerpc64-apple-darwin9.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] PPC64 ldu command generated with invalid offset

[lucier at math dot purdue dot edu]

------- Comment #1 from lucier at math dot purdue dot edu  2008-10-21 00:32 -------
Created an attachment (id=16517)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16517&action=view)
test file input

This is the .i file


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] PPC64 ldu command generated with invalid offset

[lucier at math dot purdue dot edu]

------- Comment #2 from lucier at math dot purdue dot edu  2008-10-21 00:33 -------
Created an attachment (id=16518)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16518&action=view)
test file output


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] PPC64 ldu command generated with invalid offset

[schwab at suse dot de]

------- Comment #3 from schwab at suse dot de  2008-10-21 08:36 -------
Reduced testcase:

double y, z;
void foo (long x)
{
  y = *(double *) ((long *) (x - 1) + 1);
  z = *(double *) ((long *) (x - 1) + 1);
}

$ gcc -m64 -O -c ldu.c
/tmp/ccYujYhd.s: Assembler messages:
/tmp/ccYujYhd.s:20: Error: operand out of domain (7 is not a multiple of 4)

The insn is generated during auto-inc-dec.

(insn 9 8 10 2 ldu.c:4 (set (reg:DF 122)
        (mem:DF (pre_modify:DI (reg/f:DI 119 [ D.1253 ])
                (plus:DI (reg/f:DI 119 [ D.1253 ])
                    (const_int 7 [0x7]))) [0 S8 A64])) 345 {*movdf_hardfloat64}
(expr_list:REG_INC (reg/f:DI 119 [ D.1253 ])
        (nil)))


-- 

schwab at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2008-10-21 08:36:02
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[schwab at suse dot de]

-- 

schwab at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  GCC build triplet|powerpc64-apple-darwin9.5.0 |
   GCC host triplet|powerpc64-apple-darwin9.5.0 |
 GCC target triplet|powerpc64-apple-darwin9.5.0 |powerpc64-*-*
           Keywords|                            |wrong-code
            Summary|PPC64 ldu command generated |[4.4 regression] PPC64 ldu
                   |with invalid offset         |command generated with
                   |                            |invalid offset
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[jakub at gcc dot gnu dot org]

------- Comment #4 from jakub at gcc dot gnu dot org  2008-10-21 09:55 -------
I think this is rs6000_legitimate_address at fault here, it shouldn't say it is
valid memory address.  In the:
if (GET_CODE (x) == PRE_MODIFY block in that function,
rs6000_legitimate_offset_address_p (mode, XEXP (x, 1), reg_ok_strict)
is true because:
3649          if (mode == DFmode || mode == DDmode || !TARGET_POWERPC64)
3650            extra = 4;
3651          else if (offset & 3)
3652            return false;
only checks the offset being multiple of 4 if not DFmode or DDmode.  If that is
correct, I think rs6000_legitimate_address should in the PRE_MODIFY case
explicitly check that if offset is a constant that it is multiple of 4.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dje at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[dje at gcc dot gnu dot org]

------- Comment #5 from dje at gcc dot gnu dot org  2008-10-21 14:53 -------
The test in rs6000_legitimate_offset_address_p is for something completely
different.  This should be tested in rs6000_legitimate_address:

  if (GET_CODE (x) == PRE_MODIFY
      && mode != TImode
      && mode != TFmode
      && mode != TDmode
      && ((TARGET_HARD_FLOAT && TARGET_FPRS && TARGET_DOUBLE_FLOAT)
          || TARGET_POWERPC64
          || ((mode != DFmode && mode != DDmode) || TARGET_E500_DOUBLE))
      && (TARGET_POWERPC64 || mode != DImode)
      && !ALTIVEC_VECTOR_MODE (mode)
      && !SPE_VECTOR_MODE (mode)
      /* Restrict addressing for DI because of our SUBREG hackery.  */
      && !(TARGET_E500_DOUBLE
           && (mode == DFmode || mode == DDmode || mode == DImode))
      && TARGET_UPDATE
      && legitimate_indirect_address_p (XEXP (x, 0), reg_ok_strict)
      && (rs6000_legitimate_offset_address_p (mode, XEXP (x, 1), reg_ok_strict)
          || legitimate_indexed_address_p (XEXP (x, 1), reg_ok_strict))
      && rtx_equal_p (XEXP (XEXP (x, 1), 0), XEXP (x, 0)))
    return 1;


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[jakub at gcc dot gnu dot org]

------- Comment #6 from jakub at gcc dot gnu dot org  2008-10-21 15:10 -------
Created an attachment (id=16519)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16519&action=view)
gcc44-pr37878.patch

So something like this?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[dje at gcc dot gnu dot org]

------- Comment #7 from dje at gcc dot gnu dot org  2008-10-21 15:14 -------
Also, note the problem is a DFmode value in a GPR.  FPRs can handle the
non-word-aligned offset.  Forcing all DFmode to be 64 bit aligned is not an
option because that is known to impose a severe performance penalty.  For
non-update form, we have handled this in rs6000_legitimize_reload_address.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[jakub at gcc dot gnu dot org]

------- Comment #8 from jakub at gcc dot gnu dot org  2008-10-22 11:33 -------
Created an attachment (id=16526)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16526&action=view)
gcc44-pr37878.patch

Just for the record, after discussions on IRC the bug was identified in
word_offset_memref_operand.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #16519|0                           |1
        is obsolete|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[lucier at math dot purdue dot edu]

------- Comment #9 from lucier at math dot purdue dot edu  2008-10-23 19:20 -------
I bootstrapped and regtested the suggested patch.  There was one fewer FAIL in
the gcc tests:

FAIL: gcc.c-torture/execute/nestfunc-6.c execution,  -O0 

and one more failure in the libgomp tests:

FAIL: libgomp.fortran/crayptr2.f90  -O3 -fomit-frame-pointer -funroll-loops 
execution test

However, it's not clear to me from the output of gdb implies  that this may is
a problem with the compiled code (the command lines are taken from the log
file):

[descartes:powerpc64-apple-darwin9.5.0/libgomp/testsuite] lucier%
/Users/lucier/programs/gcc/objdirs/mainline/gcc/xgcc
-B/Users/lucier/programs/gcc/objdirs/mainline/gcc/
/Users/lucier/programs/gcc/mainline/libgomp/testsuite/libgomp.fortran/crayptr2.f90

-B/Users/lucier/programs/gcc/objdirs/mainline/powerpc64-apple-darwin9.5.0/./libgomp/
-I/Users/lucier/programs/gcc/objdirs/mainline/powerpc64-apple-darwin9.5.0/./libgomp
-I/Users/lucier/programs/gcc/mainline/libgomp/testsuite/.. -shared-libgcc
-fmessage-length=0 -fopenmp  -O3 -fomit-frame-pointer -funroll-loops  -fopenmp
-fcray-pointer -static-libgcc  
-L/Users/lucier/programs/gcc/objdirs/mainline/powerpc64-apple-darwin9.5.0/./libgomp/.libs
-lgomp
-L/Users/lucier/programs/gcc/objdirs/mainline/powerpc64-apple-darwin9.5.0/./libgomp/../libgfortran/.libs
-lgfortranbegin -lgfortran -lm   -mcpu=970 -m64 -o ./crayptr2.exe
[descartes:powerpc64-apple-darwin9.5.0/libgomp/testsuite] lucier% env
LD_LIBRARY_PATH=.:/Users/lucier/programs/gcc/objdirs/mainline/powerpc64-apple-darwin9.5.0/./libgomp/.libs:/Users/lucier/programs/gcc/objdirs/mainline/gcc:/Users/lucier/programs/gcc/objdirs/mainline/powerpc64-apple-darwin9.5.0/./libgomp/../libgfortran/.libs:.:/Users/lucier/programs/gcc/objdirs/mainline/powerpc64-apple-darwin9.5.0/./libgomp/.libs:/Users/lucier/programs/gcc/objdirs/mainline/gcc:/Users/lucier/programs/gcc/objdirs/mainline/powerpc64-apple-darwin9.5.0/./libgomp/../libgfortran/.libs
gdb ./crayptr2.exe
GNU gdb 6.3.50-20050815 (Apple version gdb-962) (Sat Jul 26 08:17:57 UTC 2008)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "powerpc-apple-darwin"...Reading symbols for shared
libraries .... done

(gdb) run
Starting program:
/Users/lucier/programs/gcc/objdirs/mainline/powerpc64-apple-darwin9.5.0/libgomp/testsuite/crayptr2.exe 
warning: posix_spawn failed, trying execvp, error: 86
Reading symbols for shared libraries +++.. done

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000000
0x0000000100001678 in MAIN__.omp_fn.0 ()
(gdb) where
#0  0x0000000100001678 in MAIN__.omp_fn.0 ()
#1  0x000000010000187c in MAIN__ ()
#2  0x00000001000018e4 in main (argc=1, argv=<value temporarily unavailable,
due to optimizations>) at ../../../../mainline/libgfortran/fmain.c:21

It is completely reproducible, however.

Brad


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[lucier at math dot purdue dot edu]

------- Comment #10 from lucier at math dot purdue dot edu  2008-10-23 21:25 -------
This patch fixes my original problem and the reduced test case.

The two testresults reports I referred to earlier are at

http://gcc.gnu.org/ml/gcc-testresults/2008-10/msg01616.html

and

http://gcc.gnu.org/ml/gcc-testresults/2008-10/msg01427.html

Thanks!

Brad


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[dje at gcc dot gnu dot org]

------- Comment #11 from dje at gcc dot gnu dot org  2008-10-28 22:35 -------
Created an attachment (id=16576)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16576&action=view)
disallow illegal displacement wrapped in PRE_MODIFY or PRE_INC/DEC

I think this patch accomplishes the effect but easier to follow with the
address form localized in one place.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[dje at gcc dot gnu dot org]

------- Comment #12 from dje at gcc dot gnu dot org  2008-10-28 23:13 -------
Created an attachment (id=16577)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16577&action=view)
another refinement

Jakub suggested a further refinement to hoist a common sub-expression.


-- 

dje at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #16576|0                           |1
        is obsolete|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |dje at gcc dot gnu dot org
                   |dot org                     |
                URL|                            |http://gcc.gnu.org/ml/gcc-
                   |                            |patches/2008-
                   |                            |10/msg01220.html
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[dje at gcc dot gnu dot org]

------- Comment #13 from dje at gcc dot gnu dot org  2008-10-29 23:33 -------
Subject: Bug 37878

Author: dje
Date: Wed Oct 29 23:33:02 2008
New Revision: 141450

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=141450
Log:
        PR target/37878
        * config/rs6000/predicates.md (word_offset_memref_operand):
        Restructure code and look inside auto-inc/dec addresses.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/rs6000/predicates.md


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878

[Bug target/37878] [4.4 regression] PPC64 ldu command generated with invalid offset

[lucier at math dot purdue dot edu]

------- Comment #14 from lucier at math dot purdue dot edu  2008-10-30 00:02 -------
Thank you, this fixes the original bug.

I took the liberty of closing this bug report.

Thanks again.

Brad


-- 

lucier at math dot purdue dot edu changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37878