[Bug bootstrap/45162] New: [4.6 regression] ARM bootstrap comparison failures after stage 3

[Bug bootstrap/45162] New: [4.6 regression] ARM bootstrap comparison failures after stage 3

[mikpe at it dot uu dot se]

Attempting to bootstrap gcc-4.6-20100731 (r162788) on armv5tel-linux-gnueabi
fails due to bootstrap comparison failures after stage 3:

make[3]: Leaving directory `/home/mikpe/objdir46'
Comparing stages 2 and 3
warning: gcc/cc1plus-checksum.o differs
warning: gcc/cc1-checksum.o differs
warning: gcc/cc1objplus-checksum.o differs
warning: gcc/cc1obj-checksum.o differs
Bootstrap comparison failure!
gcc/lto-cgraph.o differs
gcc/value-prof.o differs
gcc/tree-vect-data-refs.o differs
gcc/expr.o differs
gcc/tree-ssa-loop-ivopts.o differs
gcc/lto-streamer-out.o differs
gcc/stor-layout.o differs
gcc/tree-ssa-loop-ivcanon.o differs
gcc/loop-iv.o differs
gcc/double-int.o differs
gcc/expmed.o differs
gcc/dbxout.o differs
gcc/tree.o differs
gcc/sreal.o differs
gcc/cfgloopanal.o differs
gcc/explow.o differs
libcpp/expr.o differs
make[2]: *** [compare] Error 1
make[2]: Leaving directory `/home/mikpe/objdir46'
make[1]: *** [stage3-bubble] Error 2
make[1]: Leaving directory `/home/mikpe/objdir46'
make: *** [bootstrap] Error 2

Target: armv5tel-brewer-linux-gnueabi
Configured with: /home/mikpe/gcc-4.6-20100731/configure --enable-bootstrap
--enable-shared --enable-threads=posix --enable-checking=release
--with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions
--enable-languages=c,c++,objc,obj-c++,java,fortran --enable-java-awt=gtk
--disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
--enable-libgcj-multifile --disable-java-maintainer-mode
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib
--disable-sjlj-exceptions --with-arch=armv5te --with-tune=xscale
--build=armv5tel-brewer-linux-gnueabi
--with-gmp=/home/mikpe/pkgs/linux-armv5l/gmp-4.3.2
--with-mpfr=/home/mikpe/pkgs/linux-armv5l/mpfr-2.4.2
--with-mpc=/home/mikpe/pkgs/linux-armv5l/mpc-0.8.2 --disable-plugin
--disable-lto --disable-libmudflap


-- 
           Summary: [4.6 regression] ARM bootstrap comparison failures after
                    stage 3
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mikpe at it dot uu dot se
 GCC build triplet: armv5tel-unknown-linux-gnueabi
  GCC host triplet: armv5tel-unknown-linux-gnueabi
GCC target triplet: armv5tel-unknown-linux-gnueabi


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug bootstrap/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.6.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug bootstrap/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[ramana at gcc dot gnu dot org]

------- Comment #1 from ramana at gcc dot gnu dot org  2010-08-02 14:55 -------
Confirmed. My bootstrap with thumb2 and armv7-a failed as well. Here's the
configuration line . I only see a comparison failure with tree-vect-data-refs.o
in this configuration.

Configured with: /home/ramrad01/sources//trunk/configure
--prefix=/home/ramrad01/install-nightlies/install-trunk-162814
--enable-languages=c,c++,fortran --enable-__cxa_atexit --disable-nls
--enable-threads=posix --disable-multilib --with-arch=armv7-a --with-mode=thumb
--with-float=softfp --with-fpu=vfpv3-d16


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-08-02 14:55:47
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug bootstrap/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[ramana at gcc dot gnu dot org]

------- Comment #2 from ramana at gcc dot gnu dot org  2010-08-02 14:58 -------
Created an attachment (id=21370)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21370&action=view)
Disassembly and object files that are different with the thumb2 bootstrap

Disassembly and object files in this case.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug bootstrap/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[ramana at gcc dot gnu dot org]

------- Comment #3 from ramana at gcc dot gnu dot org  2010-08-03 14:14 -------
Created an attachment (id=21375)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21375&action=view)
testcase.

The difference is in the case with and without debug info. With the attached
pre-processed file and with and without -g you can see differences in code
generated between -g and no -g . The command line options I've used to generate
this code are in a cross-compiler. 

-O2

and 

-O2 -g 

The difference in code generated in the case of debug info is with cprop
deciding to constant propagate a value of 0 into one of the instructions in the
case of with debug info and not without debug info.

We can see the difference in the case of tree-vect-data-refs.i with a cross
compiler to arm-linux-gnueabi with and without the command line options as
mentioned above.
Sorry about the largish testcase but I've not been able to reduce the testcase
further . The difference in code generation happens in
vect_analyze_data_ref_accesses - the one on the left is without debug and the
one on the right is the case with debug info for the same basic block.

.L947:                                     .L947:
      add     ip, sp, #32                  add     ip, sp, #32
      ldmia   ip, {fp-ip}                  ldmia   ip, {fp-ip}
      ldr     r4, [sp, #40]                ldr     r4, [sp, #40]
      orrs    ip, fp, ip                   orrs    ip, fp, ip
                                   >       moveq   r0, #0
      ldreq   lr, [sp, #80]                ldreq   lr, [sp, #80]
                                   >       streq   r0, [sp, #36]
      ldr     r0, [r4, #4]                 ldr     r0, [r4, #4]
      streq   lr, [sp, #32]                streq   lr, [sp, #32]
      bl      vinfo_for_stmt.isra.11       bl      vinfo_for_stmt.isra.11
      ldr     r7, [sp, #32]                ldr     r7, [sp, #32]
        str     r7, [r0, #76]              str     r7, [r0, #76]
        mov     r0, #9                     mov     r0, #9
        bl      vect_print_dump_info       bl      vect_print_dump_info
        cmp     r0, #0                     cmp     r0, #0
        bne     .L1025                     bne     .L1025


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #21370|0                           |1
        is obsolete|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug rtl-optimization/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[mikpe at it dot uu dot se]

------- Comment #4 from mikpe at it dot uu dot se  2010-08-03 21:12 -------
Created an attachment (id=21381)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21381&action=view)
reduced test case

Here is a 66-line test case, reduced from Ramana's preprocessed source, that
reliably fails -fcompare-debug when compiled by a gcc-4.6-20100731 cross to
armv5tel-linux-gnueabi hosted on i686-linux.

Diffing the disassembled object code for -g0 and -g shows:

@@ -1,5 +1,5 @@

-pr45162.o.g0:     file format elf32-littlearm
+pr45162.o.g:     file format elf32-littlearm


 Disassembly of section .text:
@@ -57,6 +57,7 @@
   c4:  e1943005        orrs    r3, r4, r5
   c8:  e1a00007        mov     r0, r7
   cc:  01a04008        moveq   r4, r8
-  d0:  ebfffffe        bl      0 <vinfo_for_stmt>
-  d4:  e5804004        str     r4, [r0, #4]
-  d8:  eaffffd0        b       20 <vinfo_for_stmt+0x20>
+  d0:  03a05000        moveq   r5, #0  ; 0x0
+  d4:  ebfffffe        bl      0 <vinfo_for_stmt>
+  d8:  e5804004        str     r4, [r0, #4]
+  dc:  eaffffcf        b       20 <vinfo_for_stmt+0x20>

My cross was configured:
/tmp/gcc-4.6-20100731/configure --target=armv5tel-unknown-linux-gnueabi
--with-arch=armv5te --with-tune=xscale
--prefix=/home/mikpe/pkgs/linux-x86/cross-armv5tel
--with-gmp=/home/mikpe/pkgs/linux-x86/gmp-4.3.2
--with-mpfr=/home/mikpe/pkgs/linux-x86/mpfr-2.4.2
--with-mpc=/home/mikpe/pkgs/linux-x86/mpc-0.8.2 --disable-plugin --disable-lto
--disable-nls --disable-shared --disable-libmudflap --disable-multilib
--enable-threads=posix --enable-checking=release --enable-languages=c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug rtl-optimization/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[kkojima at gcc dot gnu dot org]

------- Comment #5 from kkojima at gcc dot gnu dot org  2010-08-04 11:19 -------
FYI, SH fails to bootstrap with similar comparison failures:

Comparing stages 2 and 3
warning: gcc/cc1-checksum.o differs
Bootstrap comparison failure!
gcc/double-int.o differs
gcc/tree-vect-data-refs.o differs
gcc/value-prof.o differs
gcc/cgraph.o differs

for revision 162730 on sh4-unknown-linux-gnu and yes, -O2 and
-O2 -g produce different codes for those files.
The non-reduced testcase in #3 is also a testcase for SH.


-- 

kkojima at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug rtl-optimization/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[mikpe at it dot uu dot se]

------- Comment #6 from mikpe at it dot uu dot se  2010-08-04 12:27 -------
The -O2 -fcompare-debug failure on ARM is caused by r162678:
http://gcc.gnu.org/ml/gcc-cvs/2010-07/msg01032.html

Both the original large testcase and the reduced one compile fine with
gcc-4.6-r162677 -O2 -fcompare-debug, but fail with r162678.

I haven't checked more recent revisions yet due to PR45177.


-- 

mikpe at it dot uu dot se changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug rtl-optimization/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[bernds at gcc dot gnu dot org]

------- Comment #7 from bernds at gcc dot gnu dot org  2010-08-04 12:47 -------
Created an attachment (id=21394)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=21394&action=view)
A patch that should fix it

DEBUG_INSNs got me again.  Actually the old byte dce was disabled and thus not
converted to handling them.

Try this patch.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug rtl-optimization/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[bernds at gcc dot gnu dot org]

------- Comment #8 from bernds at gcc dot gnu dot org  2010-08-04 15:16 -------
*** Bug 45150 has been marked as a duplicate of this bug. ***


-- 

bernds at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug rtl-optimization/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[danglin at gcc dot gnu dot org]

------- Comment #9 from danglin at gcc dot gnu dot org  2010-08-04 16:38 -------
The patch fixes the darwin comparison failure.


-- 

danglin at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug rtl-optimization/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[mikpe at it dot uu dot se]

------- Comment #10 from mikpe at it dot uu dot se  2010-08-04 20:13 -------
Bernd's patch fixes the -fcompare-debug failures in my arm cross-compiler.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug rtl-optimization/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[bernds at gcc dot gnu dot org]

------- Comment #11 from bernds at gcc dot gnu dot org  2010-08-04 21:07 -------
Subject: Bug 45162

Author: bernds
Date: Wed Aug  4 21:07:05 2010
New Revision: 162881

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=162881
Log:
        PR rtl-optimization/45162
        * df-problems.c (df_word_lr_bb_local_compute): Ignore DEBUG_INSNs.
        * dce.c (word_dce_process_block): Likewise.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/dce.c
    trunk/gcc/df-problems.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162

[Bug rtl-optimization/45162] [4.6 regression] ARM bootstrap comparison failures after stage 3

[bernds at gcc dot gnu dot org]

------- Comment #12 from bernds at gcc dot gnu dot org  2010-08-04 21:14 -------
Fixed.


-- 

bernds at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45162