[Bug c/28752] New: bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[Bug c/28752] New: bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[victork at il dot ibm dot com]

svn revision: 116108

make bootstrap BOOT_CFLAGS="-O2 -ftree-vectorize -maltivec" 2>&1 | tee
build.log

Comparing stages 2 and 3
/home/victork/mainline-merge/build/stage3-gcc
Bootstrap comparison failure!
./gcc.o differs
make[2]: *** [compare] Error 1
make[2]: Leaving directory `/home/victork/mainline-merge/build'
make[1]: *** [stage3-bubble] Error 2
make[1]: Leaving directory `/home/victork/mainline-merge/build'
make: *** [bootstrap] Error 2

 % stage3-gcc/xgcc -v
Using built-in specs.
Target: powerpc64-unknown-linux-gnu
Configured with: ../gcc/configure --prefix=/Develop/mainline-merge
--enable-bootstrap --enable-languages=c,c++
Thread model: posix
gcc version 4.2.0 20060813 (experimental)

 % uname -a
Linux mac-victork.haifa.ibm.com 2.6.10-1.yhpc.1smp #1 SMP Thu Mar 17 19:38:06
MST 2005 ppc64 ppc64 ppc64 GNU/Linux
System compiler:
 % gcc -v
Reading specs from /usr/lib/gcc-lib/ppc64-yellowdog-linux/3.3.3/specs
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--disable-checking --with-system-zlib --enable-__cxa_atexit
--enable-symvers=gnu --host=ppc64-yellowdog-linux --build=ppc64-yellowdog-linux
--target=ppc64-yellowdog-linux --with-cpu=default32 --enable-biarch
Thread model: posix
gcc version 3.3.3 (Yellow Dog Linux 3.3.3-16.ydl.8)


-- 
           Summary: bootstrap comparision fails with "-ftree-vectorize -
                    maltivec" on ppc
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: victork at il dot ibm dot com
 GCC build triplet: powerpc64-linux
  GCC host triplet: powerpc64-linux
GCC target triplet: powerpc64-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug c/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[victork at il dot ibm dot com]

------- Comment #1 from victork at il dot ibm dot com  2006-08-16 09:19 -------
gcc.o diff:

--- x   2006-08-16 12:16:58.669218328 +0300
+++ y   2006-08-16 12:17:05.353268576 +0300
@@ -1,6 +1,6 @@

-stage2-gcc/gcc.o:     file format elf64-powerpc
-stage2-gcc/gcc.o
+stage3-gcc/gcc.o:     file format elf64-powerpc
+stage3-gcc/gcc.o
 architecture: powerpc:common64, flags 0x00000011:
 HAS_RELOC, HAS_SYMS
 start address 0x0000000000000000
@@ -7272,7 +7272,7 @@
     60a8:      e9 73 01 20     ld      r11,288(r19)
     60ac:      1d 29 00 18     mulli   r9,r9,24
     60b0:      7f 89 59 2a     stdx    r28,r9,r11
-    60b4:      7f 49 5a 14     add     r26,r9,r11
+    60b4:      7f a9 5a 14     add     r29,r9,r11
     60b8:      41 8e 01 94     beq-    cr3,624c <.process_command+0x222c>
     60bc:      2f 9b 00 55     cmpwi   cr7,r27,85
     60c0:      41 9e 01 8c     beq-    cr7,624c <.process_command+0x222c>
@@ -7301,7 +7301,7 @@
     611c:      2f 9b 00 47     cmpwi   cr7,r27,71
     6120:      41 9e 01 2c     beq-    cr7,624c <.process_command+0x222c>
     6124:      88 1c 00 01     lbz     r0,1(r28)
-    6128:      3b 1c 00 01     addi    r24,r28,1
+    6128:      3b 5c 00 01     addi    r26,r28,1
     612c:      7c 00 00 d0     neg     r0,r0
     6130:      78 1e 0f e0     rldicl  r30,r0,1,63
     6134:      e8 82 01 e0     ld      r4,480(r2)
@@ -7347,7 +7347,7 @@
     61b8:      e9 33 01 1a     lwa     r9,280(r19)
     61bc:      e8 13 01 20     ld      r0,288(r19)
     61c0:      f8 7d 00 08     std     r3,8(r29)
-    61c4:      7f 03 c3 78     mr      r3,r24
+    61c4:      7f 43 d3 78     mr      r3,r26
     61c8:      1d 29 00 18     mulli   r9,r9,24
     61cc:      7d 29 02 14     add     r9,r9,r0
     61d0:      eb a9 00 08     ld      r29,8(r9)
@@ -7385,7 +7385,7 @@
     6244:      90 13 01 18     stw     r0,280(r19)
     6248:      4b ff e7 38     b       4980 <.process_command+0x960>
     624c:      88 1c 00 01     lbz     r0,1(r28)
-    6250:      3b 1c 00 01     addi    r24,r28,1
+    6250:      3b 5c 00 01     addi    r26,r28,1
     6254:      7c 00 00 d0     neg     r0,r0
     6258:      78 1e 0f e1     rldicl. r30,r0,1,63
     625c:      40 82 fe d8     bne+    6134 <.process_command+0x2114>
@@ -7435,8 +7435,8 @@
     62fc:      78 00 d1 82     rldicl  r0,r0,58,6
     6300:      7f de 00 50     subf    r30,r30,r0
     6304:      7c 1e ba 14     add     r0,r30,r23
-    6308:      7c 1d 07 b4     extsw   r29,r0
-    630c:      7f 99 e8 00     cmpw    cr7,r25,r29
+    6308:      7c 1b 07 b4     extsw   r27,r0
+    630c:      7f 99 d8 00     cmpw    cr7,r25,r27
     6310:      40 9d 05 10     ble-    cr7,6820 <.process_command+0x2800>
     6314:      38 7e 00 01     addi    r3,r30,1
     6318:      7c 63 07 b4     extsw   r3,r3
@@ -7446,7 +7446,7 @@
     6324:      60 00 00 00     nop
     6328:      2f 9e 00 00     cmpwi   cr7,r30,0
     632c:      39 40 00 00     li      r10,0
-    6330:      f8 7a 00 08     std     r3,8(r26)
+    6330:      f8 7d 00 08     std     r3,8(r29)
     6334:      40 9d 00 58     ble-    cr7,638c <.process_command+0x236c>
     6338:      e9 33 01 1a     lwa     r9,280(r19)
     633c:      e9 53 01 20     ld      r10,288(r19)
@@ -7468,7 +7468,7 @@
     637c:      39 29 00 08     addi    r9,r9,8
     6380:      42 00 ff f0     bdnz+   6370 <.process_command+0x2350>
     6384:      7b ca 1f 24     rldicr  r10,r30,3,60
-    6388:      7f b7 eb 78     mr      r23,r29
+    6388:      7f 77 db 78     mr      r23,r27
     638c:      e9 33 01 1a     lwa     r9,280(r19)
     6390:      e8 13 01 20     ld      r0,288(r19)
     6394:      1d 29 00 18     mulli   r9,r9,24
@@ -7503,16 +7503,16 @@
     63f8:      60 00 00 00     nop
     63fc:      2e 23 00 00     cmpdi   cr4,r3,0
     6400:      41 92 fd 64     beq+    cr4,6164 <.process_command+0x2144>
-    6404:      eb a2 01 f8     ld      r29,504(r2)
+    6404:      eb 02 01 f8     ld      r24,504(r2)
                        6406: R_PPC64_TOC16_DS  .toc+0x1f8
     6408:      7f 83 e3 78     mr      r3,r28
-    640c:      7f a4 eb 78     mr      r4,r29
+    640c:      7f 04 c3 78     mr      r4,r24
     6410:      48 00 00 01     bl      6410 <.process_command+0x23f0>
                        6410: R_PPC64_REL24     .strcmp
     6414:      60 00 00 00     nop
     6418:      2f a3 00 00     cmpdi   cr7,r3,0
     641c:      40 9e 01 f8     bne-    cr7,6614 <.process_command+0x25f4>
-    6420:      7f a4 eb 78     mr      r4,r29
+    6420:      7f 04 c3 78     mr      r4,r24
     6424:      7f 83 e3 78     mr      r3,r28
     6428:      48 00 00 01     bl      6428 <.process_command+0x2408>
                        6428: R_PPC64_REL24     .strcmp
@@ -7870,7 +7870,7 @@
     6870:      40 9e 00 64     bne-    cr7,68d4 <.process_command+0x28b4>
     6874:      3a 80 00 00     li      r20,0
     6878:      4b ff e1 08     b       4980 <.process_command+0x960>
-    687c:      f8 7a 00 08     std     r3,8(r26)
+    687c:      f8 7d 00 08     std     r3,8(r29)
     6880:      4b ff f9 7c     b       61fc <.process_command+0x21dc>
     6884:      e8 82 01 f0     ld      r4,496(r2)
                        6886: R_PPC64_TOC16_DS  .toc+0x1f0
@@ -7880,7 +7880,7 @@
     6890:      60 00 00 00     nop
     6894:      2e 23 00 00     cmpdi   cr4,r3,0
     6898:      41 92 f9 f8     beq+    cr4,6290 <.process_command+0x2270>
-    689c:      eb a2 01 f8     ld      r29,504(r2)
+    689c:      eb 02 01 f8     ld      r24,504(r2)
                        689e: R_PPC64_TOC16_DS  .toc+0x1f8
     68a0:      4b ff fb 80     b       6420 <.process_command+0x2400>
     68a4:      e8 62 04 38     ld      r3,1080(r2)


-- 

victork at il dot ibm dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|bootstrap comparision fails |bootstrap comparision fails
                   |with "-ftree-vectorize -    |with "-ftree-vectorize -
                   |maltivec" on ppc            |maltivec" on ppc


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug c/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[pluto at agmk dot net]

------- Comment #2 from pluto at agmk dot net  2006-08-16 09:23 -------
probably the same issue as PR20586.


-- 

pluto at agmk dot net changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pluto at agmk dot net


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

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------- Comment #3 from irar at il dot ibm dot com  2006-10-30 11:33 -------
I am getting another failure:

/home/irar/main-boot/build7/./gcc/xgcc -B/home/irar/main-boot/build7/./gcc/
-B/home/irar/main-boot/ppc64-redhat-linux/bin/
-B/home/irar/main-boot/ppc64-redhat-linux/lib/ -isystem
/home/irar/main-boot/ppc64-redhat-linux/include -isystem
/home/irar/main-boot/ppc64-redhat-linux/sys-include -O2 -O2 -g -O2  -DIN_GCC   
-W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes
-Wold-style-definition  -isystem ./include  -I. -Inof -I../../gcc/gcc
-I../../gcc/gcc/nof -I../../gcc/gcc/../include
-I../../gcc/gcc/../libcpp/include  -I../../gcc/gcc/../libdecnumber
-I../libdecnumber -msoft-float -fPIC -mstrict-align -g0
-finhibit-size-directive -fno-inline-functions -fno-exceptions
-fno-zero-initialized-in-bss -fno-toplevel-reorder  -msdata=none \
  -c ../../gcc/gcc/crtstuff.c -DCRT_END \
  -o nof/crtend.o
../../gcc/gcc/crtstuff.c: In function â__do_global_dtors_auxâ:
../../gcc/gcc/crtstuff.c:304: internal compiler error: in push_reload, at
reload.c:1294
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
../../gcc/gcc/crtstuff.c: In function â__do_global_ctors_auxâ:
../../gcc/gcc/crtstuff.c:522: internal compiler error: in push_reload, at
reload.c:1294
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
make[5]: *** [nof/crtbegin.o] Error 1
make[5]: *** Waiting for unfinished jobs....
make[5]: *** [nof/crtend.o] Error 1
make[5]: Leaving directory `/home/irar/main-boot/build7/gcc'
make[4]: *** [extranof] Error 2
make[4]: Leaving directory `/home/irar/main-boot/build7/gcc'

I found out that this happens when the loop in config/rs6000/rs6000.c:3674 is
vectorized. Here it is:
for (i = 32; i < 64; i++)
    fixed_regs[i] = call_used_regs[i]
        = call_really_used_regs[i] = 1;

Also if the loop is split to 
for (i = 32; i < 64; i++)
    fixed_regs[i] = 1;
and the rest, and only this loop is vectorized, the same error occurs.

I made a testcase with the original loop, but it works fine.

Ira


-- 

irar at il dot ibm dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |irar at il dot ibm dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 2404 bytes --]



------- Comment #4 from irar at il dot ibm dot com  2006-11-02 11:18 -------
The loop at config/rs6000/rs6000.c:3674 requires versioning for alignment, so
when bootstrapping with 
"-ftree-vectorize -fno-tree-vect-loop-version" it does not get vectorized.
However, we still fail bootstrap... This is the failure we get:

/home/irar/main-boot/build17/./gcc/xgcc -B/home/irar/main-boot/build17/./gcc/
-B/home/irar/main-boot/ppc64-redhat-linux/bin/
-B/home/irar/main-boot/ppc64-redhat-linux/lib/ -isystem
/home/irar/main-boot/ppc64-redhat-linux/include -isystem
/home/irar/main-boot/ppc64-redhat-linux/sys-include -O2 -O2 -g -O2  -DIN_GCC   
-W -Wall -Wwrite-strings -Wstrict-prototypes -Wmissing-prototypes
-Wold-style-definition  -isystem ./include  -I. -I. -I../../gcc/gcc
-I../../gcc/gcc/. -I../../gcc/gcc/../include -I../../gcc/gcc/../libcpp/include 
-I../../gcc/gcc/../libdecnumber -I../libdecnumber  -g0 -finhibit-size-directive
-fno-inline-functions -fno-exceptions -fno-zero-initialized-in-bss
-fno-toplevel-reorder  -msdata=none \
  -c ../../gcc/gcc/crtstuff.c -DCRT_BEGIN \
  -o crtbegin.o
../../gcc/gcc/crtstuff.c: In function â__do_global_dtors_auxâ:
../../gcc/gcc/crtstuff.c:304: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
make[3]: *** [crtbegin.o] Error 1
make[3]: *** Waiting for unfinished jobs....
rm fsf-funding.pod gcov.pod gfdl.pod cpp.pod gcc.pod gfortran.pod gpl.pod
make[3]: Leaving directory `/home/irar/main-boot/build17/gcc'
make[2]: *** [all-stage2-gcc] Error 2
make[2]: Leaving directory `/home/irar/main-boot/build17'
make[1]: *** [stage2-bubble] Error 2
make[1]: Leaving directory `/home/irar/main-boot/build17'
make: *** [bootstrap] Error 2

I found that this time a different loop in rs6000 is related to the failure -
when it is vectorized, the Stage2 compiler is "bad", and when we force the loop
not to be vectorized, the Stage2 compiler is "good" (bootstrap passes with
vectorization enabled). The loop is config/rs6000/rs6000.c:17204:

  for (i = 0; i < issue_rate; i++)
     {
          group_insns[i] = 0;
     }


Looks like the problem is not related to some specific loop vectorization.
Don't know if it makes sense to try to create a reduced testcase (or how...).

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #5 from irar at il dot ibm dot com  2006-11-02 11:44 -------
I found that revision 110671 passed bootstrap with vectorization enabled, and
revision 110846 failed bootstrap with vectorization enabled (but passed w/o).

Janis - could you help track down the patch that exposed/caused the bootstrap
failure with "BOOT_CFLAGS="-O2 -g -ftree-vectorize -maltivec""?

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[janis at gcc dot gnu dot org]

------- Comment #6 from janis at gcc dot gnu dot org  2006-11-03 00:08 -------
A regression hunt on powerpc64-linux identified the following large patch:

    http://gcc.gnu.org/viewcvs?view=rev&rev=110705

    r110705 | law | 2006-02-07 18:31:27 +0000 (Tue, 07 Feb 2006)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #7 from irar at il dot ibm dot com  2006-11-06 09:38 -------
Janis - thanks a lot for your help!

> http://gcc.gnu.org/viewcvs?view=rev&rev=110705
> r110705 | law | 2006-02-07 18:31:27 +0000 (Tue, 07 Feb 2006)

In r110704 bootstrap passes with and w/o vectorization enabled, and in r110705
boostrap fails in both cases (also without vectorization).

The patch 

2006-02-08  Jeff Law  <law@redhat.com>

        PR tree-optimization/26169
        * tree-vrp.c (execute_vrp): Perform any queued SSA updates before
        threading jumps.

(http://gcc.gnu.org/viewcvs?view=rev&revision=110758)

fixes bootstrap without vectorization, but bootstrap with "BOOT_CFLAGS="-O2 -g
-ftree-vectorize -maltivec" still fails.

Ira


-- 

irar at il dot ibm dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at redhat dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[law at redhat dot com]

------- Comment #8 from law at redhat dot com  2006-11-06 17:37 -------
Subject: Re:  bootstrap comparision fails with
        "-ftree-vectorize -maltivec" on ppc

On Mon, 2006-11-06 at 09:39 +0000, irar at il dot ibm dot com wrote:
> 
> ------- Comment #7 from irar at il dot ibm dot com  2006-11-06 09:38 -------
> Janis - thanks a lot for your help!
> 
> > http://gcc.gnu.org/viewcvs?view=rev&rev=110705
> > r110705 | law | 2006-02-07 18:31:27 +0000 (Tue, 07 Feb 2006)
> 
> In r110704 bootstrap passes with and w/o vectorization enabled, and in r110705
> boostrap fails in both cases (also without vectorization).
> 
> The patch 
> 
> 2006-02-08  Jeff Law  <law@redhat.com>
> 
>         PR tree-optimization/26169
>         * tree-vrp.c (execute_vrp): Perform any queued SSA updates before
>         threading jumps.
> 
> (http://gcc.gnu.org/viewcvs?view=rev&revision=110758)
> 
> fixes bootstrap without vectorization, but bootstrap with "BOOT_CFLAGS="-O2 -g
> -ftree-vectorize -maltivec" still fails.
Unfortunately I don't have a PPC64 I can use for bootstrap tests.

However, the failure you're seeing occurs when the stage1 compiler is
compiling crtbegin (or some other file), then send me the appropriate
.i file and I will be able to look at it with a cross compiler.

Jeff


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #9 from irar at il dot ibm dot com  2006-11-07 08:31 -------
In r110758 (and r110705) bootstrap with BOOT_CFLAGS="-O2 -g -ftree-vectorize
-maltivec" fails with another error:

/Develop/main-110758/build-vect/./prev-gcc/xgcc
-B/Develop/main-110758/build-vect/./prev-gcc/
-B/Develop/main-110758//powerpc64-suse-linux/bin/ -c   -O2 -g -ftree-vectorize
-maltivec -DIN_GCC   -W -Wall -Wwrite-strings -Wstrict-prototypes
-Wmissing-prototypes -pedantic -Wno-long-long -Wno-variadic-macros
-Wno-overlength-strings -Wold-style-definition -Wmissing-format-attribute
-Werror    -DHAVE_CONFIG_H -I. -I. -I../../gcc/gcc -I../../gcc/gcc/.
-I../../gcc/gcc/../include -I../../gcc/gcc/../libcpp/include 
-I../../gcc/gcc/../libdecnumber -I../libdecnumber    ../../gcc/gcc/regmove.c -o
regmove.o
../../gcc/gcc/recog.c: In function constrain_operands:
../../gcc/gcc/recog.c:2270: internal compiler error: in mark_operand_necessary,
at tree-ssa-dce.c:266
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
make[3]: *** [recog.o] Error 1
make[3]: *** Waiting for unfinished jobs....
rm cpp.pod gfdl.pod gfortran.pod fsf-funding.pod gpl.pod gcc.pod gcov.pod
make[3]: Leaving directory `/Develop/main-110758/build-vect/gcc'
make[2]: *** [all-stage2-gcc] Error 2
make[2]: Leaving directory `/Develop/main-110758/build-vect'
make[1]: *** [stage2-bubble] Error 2
make[1]: Leaving directory `/Develop/main-110758/build-vect'
make: *** [bootstrap] Error 2

The "guilty" loop is recog.c:2283, i.e., forcing this loop not to get
vectorized makes bootstrap with vectorization to pass.


The backtrace:

Breakpoint 1, fancy_abort (file=0x107b4668 "../../gcc/gcc/tree-ssa-dce.c",
line=266, function=0x107b4930 "mark_operand_necessary")
    at ../../gcc/gcc/diagnostic.c:642
642       internal_error ("in %s, at %s:%d", function, trim_filename (file),
line);
(gdb) backtrace
#0  fancy_abort (file=0x107b4668 "../../gcc/gcc/tree-ssa-dce.c", line=266,
function=0x107b4930 "mark_operand_necessary")
    at ../../gcc/gcc/diagnostic.c:642
During symbol reading, incomplete CFI data; unspecified registers (e.g., r0) at
0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r2) at
0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r3) at
0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r4) at
0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r5) at
0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r6) at
0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r7) at
0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r8) at
0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r9) at
0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r10)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r11)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r12)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r13)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r14)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r15)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r16)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r17)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r18)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r19)
at 0x10203008.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r20)
at 0x10203008.
#1  0x105d2654 in mark_operand_necessary (op=0xf6d34e40, phionly=0 '\0') at
../../gcc/gcc/tree-ssa-dce.c:266
#2  0x105d218c in propagate_necessity (el=0x10ad6000) at
../../gcc/gcc/tree-ssa-dce.c:553
#3  0x105d401c in perform_tree_ssa_dce (aggressive=1 '\001') at
../../gcc/gcc/tree-ssa-dce.c:906
#4  0x105d4148 in tree_ssa_cd_dce () at ../../gcc/gcc/tree-ssa-dce.c:947
#5  0x1051b110 in execute_one_pass (pass=0x1088c584) at
../../gcc/gcc/passes.c:853
#6  0x1051b2c8 in execute_pass_list (pass=0x1088c584) at
../../gcc/gcc/passes.c:897
#7  0x1051b2f4 in execute_pass_list (pass=0x108876dc) at
../../gcc/gcc/passes.c:898
#8  0x100b1684 in tree_rest_of_compilation (fndecl=0xf7862d00) at
../../gcc/gcc/tree-optimize.c:412
#9  0x10016914 in c_expand_body (fndecl=0xf7862d00) at
../../gcc/gcc/c-decl.c:6689
#10 0x1059b914 in cgraph_expand_function (node=0xf75b3e00) at
../../gcc/gcc/cgraphunit.c:1101
#11 0x1059bba4 in cgraph_expand_all_functions () at
../../gcc/gcc/cgraphunit.c:1166
#12 0x1059c798 in cgraph_optimize () at ../../gcc/gcc/cgraphunit.c:1434
#13 0x1001a024 in c_write_global_declarations () at ../../gcc/gcc/c-decl.c:7804
#14 0x104d99a8 in compile_file () at ../../gcc/gcc/toplev.c:1012
#15 0x104dbc64 in do_compile () at ../../gcc/gcc/toplev.c:1957
#16 0x104dbcf8 in toplev_main (argc=54, argv=0xffe37c74) at
../../gcc/gcc/toplev.c:1989
#17 0x10090518 in main (argc=54, argv=0xffe37c74) at ../../gcc/gcc/main.c:35

Attached recog.i.
Please let me know if you need additional information.

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #10 from irar at il dot ibm dot com  2006-11-07 08:32 -------
Created an attachment (id=12560)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12560&action=view)
recog.i


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[law at redhat dot com]

------- Comment #11 from law at redhat dot com  2006-11-07 21:03 -------
Subject: Re:  bootstrap comparision fails with
        "-ftree-vectorize -maltivec" on ppc

On Tue, 2006-11-07 at 08:31 +0000, irar at il dot ibm dot com wrote:
> 
> ------- Comment #9 from irar at il dot ibm dot com  2006-11-07 08:31 -------
> In r110758 (and r110705) bootstrap with BOOT_CFLAGS="-O2 -g -ftree-vectorize
> -maltivec" fails with another error:
[ ... ]
I've been unable to make any progress with this.

It's not even clear to me right now that the .i file you sent is valid.
Every compiler I've tried to use to process that .i file complains
that the size of the test_real_width array is negative.  

Clearly I'm doing something different than you are.

I can speculate that one of a few things might be happening.


  1. We might have some kind of memory corruption or similar bug
     causing us to zero the SSA_NAME_DEF_STMT/TREE_CHAIN field of
     the affected SSA_NAME.  Possible, but unlikely.

  2. We have an SSA_NAME in the IL which was deleted.

  3. Something else totally unexpected.


#2 has happened in the past and I'd consider it the most likely
culprit.  What is interesting is that a checking failure was not
triggered -- our SSA verifiers should be checking for case #2 and
issuing an error.

So let's start with checking a couple things.

  1. Put a breakpoint in tree_ssa_cd_dce when compiling the
     offending function from recog.c.    When that breakpoint
     triggers issue:

     verify_ssa (true)

     I can't see any way for that to fail, but better safe than
     sorry.

  2. When the gcc_assert triggers, issue:

     debug_tree (op)
     debug_generic_stmt (op)

  3. Send me the phi-only copyprop dumps.


If #1 passes and #2 indicates the name in question is on the free
list, then either DCE is mucking things up or we have out-of-date
operands in the operand cache relative to the IL (which I can
detect with the dumps).

Jeff


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #12 from irar at il dot ibm dot com  2006-11-08 08:40 -------
Jeff,

Thanks a lot! I will do the things you've suggested shortly. Meanwhile, out of
curiosity, I am attaching a "good" recog.i (built with vectorization enabled,
but the offending loop was not vectorized).

BTW, here is the compiler configuration:
../gcc/configure   --enable-threads=posix --prefix=/Develop/main-110758/
--enable-checking=release --enable-ssp --disable-libssp --enable-java-awt=gtk
--enable-gtk-cairo --disable-libjava-multilib --with-system-zlib
--enable-shared --enable-__cxa_atexit --enable-libstdcxx-allocator=new
--without-system-libunwind --with-cpu=default32 --enable-secureplt
--with-long-double-128 --host=powerpc64-suse-linux
--enable-languages=c,c++,fortran

My system compiler is gcc version 4.1.0 (SUSE Linux).

Thanks,
Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #13 from irar at il dot ibm dot com  2006-11-08 08:41 -------
Created an attachment (id=12568)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12568&action=view)
"good" recog.i


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #14 from irar at il dot ibm dot com  2006-11-08 11:33 -------
(In reply to comment #11)
>   1. Put a breakpoint in tree_ssa_cd_dce when compiling the
>      offending function from recog.c.    When that breakpoint
>      triggers issue:
>      verify_ssa (true)
>      I can't see any way for that to fail, but better safe than
>      sorry.

It fails...

Breakpoint 6, tree_ssa_cd_dce () at ../../gcc/gcc/tree-ssa-dce.c:947
947       perform_tree_ssa_dce (/*aggressive=*/optimize >= 2);
(gdb) p verify_ssa (true)
No symbol "true" in current context.
(gdb) p verify_ssa (1)
During symbol reading, incomplete CFI data; unspecified registers (e.g., r0) at
0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r2) at
0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r3) at
0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r4) at
0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r5) at
0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r6) at
0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r7) at
0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r8) at
0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r9) at
0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r10)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r11)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r12)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r13)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r14)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r15)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r16)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r17)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r18)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r19)
at 0x105d412c.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r20)
at 0x105d412c.
../../gcc/gcc/recog.c: In function constrain_operands:
../../gcc/gcc/recog.c:2270: error: expected an SSA_NAME object

Breakpoint 1, fancy_abort (file=0x10744d58 "../../gcc/gcc/tree-ssa-operands.c",
line=1905, function=0x10745428 "verify_imm_links")
    at ../../gcc/gcc/diagnostic.c:642
642       internal_error ("in %s, at %s:%d", function, trim_filename (file),
line);
The program being debugged stopped while in a function called from GDB.
When the function (verify_ssa) is done executing, GDB will silently
stop (instead of continuing to evaluate the expression containing
the function call).

Backtrace:
#0  fancy_abort (file=0x10744d58 "../../gcc/gcc/tree-ssa-operands.c",
line=1905, function=0x10745428 "verify_imm_links")
    at ../../gcc/gcc/diagnostic.c:642
#1  0x100e4c10 in verify_imm_links (f=0xffec4a8, var=0xf6d34e40) at
../../gcc/gcc/tree-ssa-operands.c:1905
#2  0x100ac1fc in verify_use (bb=0xf73144d0, def_bb=0x1, use_p=0xf6beb118,
stmt=0xf74510f0, check_abnormal=0 '\0', is_virtual=1 '\001', 
    names_defined_in_bb=0x10a8d9d0) at ../../gcc/gcc/tree-ssa.c:228
#3  0x100ae404 in verify_ssa (check_modified_stmt=1 '\001') at
../../gcc/gcc/tree-ssa.c:735
#4  <function called from gdb>
#5  tree_ssa_cd_dce () at ../../gcc/gcc/tree-ssa-dce.c:947
#6  0x1051b110 in execute_one_pass (pass=0x1088c584) at
../../gcc/gcc/passes.c:853
#7  0x1051b2c8 in execute_pass_list (pass=0x1088c584) at
../../gcc/gcc/passes.c:897
#8  0x1051b2f4 in execute_pass_list (pass=0x108876dc) at
../../gcc/gcc/passes.c:898
#9  0x100b1684 in tree_rest_of_compilation (fndecl=0xf7862d00) at
../../gcc/gcc/tree-optimize.c:412
#10 0x10016914 in c_expand_body (fndecl=0xf7862d00) at
../../gcc/gcc/c-decl.c:6689
#11 0x1059b914 in cgraph_expand_function (node=0xf75b3e00) at
../../gcc/gcc/cgraphunit.c:1101
#12 0x1059bba4 in cgraph_expand_all_functions () at
../../gcc/gcc/cgraphunit.c:1166
#13 0x1059c798 in cgraph_optimize () at ../../gcc/gcc/cgraphunit.c:1434
#14 0x1001a024 in c_write_global_declarations () at ../../gcc/gcc/c-decl.c:7804
#15 0x104d99a8 in compile_file () at ../../gcc/gcc/toplev.c:1012
#16 0x104dbc64 in do_compile () at ../../gcc/gcc/toplev.c:1957
#17 0x104dbcf8 in toplev_main (argc=54, argv=0xffdf2c74) at
../../gcc/gcc/toplev.c:1989
#18 0x10090518 in main (argc=54, argv=0xffdf2c74) at ../../gcc/gcc/main.c:35

(gdb) p debug_tree (0xf6d34e40)
 <struct_field_tag 0xf6d34e40 SFT.1940
    type <array_type 0xf78709a0
        type <pointer_type 0xf7d0c3f0 rtx type <record_type 0xf7d0c310 rtx_def>
            sizes-gimplified asm_written public unsigned SI
            size <integer_cst 0xf7eb0860 constant invariant 32>
            unit size <integer_cst 0xf7eb0520 constant invariant 4>
            align 32 symtab -137297872 alias set -1
            pointer_to_this <pointer_type 0xf798f310>>
        asm_written BLK
        size <integer_cst 0xf785ad60 constant invariant 960>
        unit size <integer_cst 0xf79811e0 constant invariant 120>
        align 32 symtab -142141712 alias set 99
        domain <integer_type 0xf7870930 type <integer_type 0xf7eae150 unsigned
int>
            sizes-gimplified public SI size <integer_cst 0xf7eb0860 32> unit
size <integer_cst 0xf7eb0520 4>
            align 32 symtab 0 alias set -1 precision 32 min <integer_cst
0xf7eb0540 0> max <integer_cst 0xf7ccd100 29>>
        pointer_to_this <pointer_type 0xf74261c0>>
    addressable used public static file ../../gcc/gcc/recog.c line 2270>
$1 = void
(gdb) p debug_generic_stmt (0xf74510f0)
#   VUSE <SFT.1940D.29535>;
#   VUSE <TMT.1945D.29540_551>;
opD.24623_172 = recog_dataD.15550.operandD.15539[opnoD.24621_29];

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #15 from irar at il dot ibm dot com  2006-11-08 12:05 -------
Additional behavior:

If I run bootstrap with BOOT_CFLAGS="-O2 -g -ftree-vectorize -maltivec"
(without -fdump-tree-vect-details), bootstrap fails with 

../../gcc/gcc/recog.c: In function constrain_operands:
../../gcc/gcc/recog.c:2270: internal compiler error: in mark_operand_necessary,
at tree-ssa-dce.c:266

Then I compile recog.c alone with 

/Develop/main-110758/build-vect/./prev-gcc/xgcc
-B/Develop/main-110758/build-vect/./prev-gcc/
-B/Develop/main-110758//powerpc64-suse-linux/bin/ -c   -O2 -g -ftree-vectorize
-maltivec -DIN_GCC   -W -Wall -Wwrite-strings -Wstrict-prototypes
-Wmissing-prototypes -pedantic -Wno-long-long -Wno-variadic-macros
-Wno-overlength-strings -Wold-style-definition -Wmissing-format-attribute
-Werror    -DHAVE_CONFIG_H -I. -I. -I../../gcc/gcc -I../../gcc/gcc/.
-I../../gcc/gcc/../include -I../../gcc/gcc/../libcpp/include 
-I../../gcc/gcc/../libdecnumber -I../libdecnumber    ../../gcc/gcc/recog.c

and again I get 

../../gcc/gcc/recog.c: In function constrain_operands:
../../gcc/gcc/recog.c:2270: internal compiler error: in mark_operand_necessary,
at tree-ssa-dce.c:266


With -quiet I get a different error:

Program received signal SIGSEGV, Segmentation fault.
0x100b1dc4 in is_gimple_min_invariant (t=0x18) at
../../gcc/gcc/tree-gimple.c:172
172       switch (TREE_CODE (t))
(gdb) backtrace
#0  0x100b1dc4 in is_gimple_min_invariant (t=0x18) at
../../gcc/gcc/tree-gimple.c:172
During symbol reading, incomplete CFI data; unspecified registers (e.g., r0) at
0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r2) at
0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r3) at
0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r4) at
0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r5) at
0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r6) at
0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r7) at
0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r8) at
0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r9) at
0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r10)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r11)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r12)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r13)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r14)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r15)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r16)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r17)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r18)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r19)
at 0x100b1dbc.
During symbol reading, incomplete CFI data; unspecified registers (e.g., r20)
at 0x100b1dbc.
#1  0x1013f110 in replace_vuses_in (stmt=0xf74510f0,
replaced_addresses_p=0xff8a9790 "", prop_value=0x10b6b238)
    at ../../gcc/gcc/tree-ssa-propagate.c:958
#2  0x1013f8d4 in substitute_and_fold (prop_value=0x10b6b238, use_ranges_p=0
'\0') at ../../gcc/gcc/tree-ssa-propagate.c:1139
#3  0x100dd070 in fini_copy_prop () at ../../gcc/gcc/tree-ssa-copy.c:914
#4  0x100dd158 in execute_copy_prop (store_copy_prop=0 '\0', phis_only=1
'\001') at ../../gcc/gcc/tree-ssa-copy.c:1035
#5  0x100dd204 in do_phi_only_copy_prop () at
../../gcc/gcc/tree-ssa-copy.c:1076
#6  0x1051b090 in execute_one_pass (pass=0x10915e68) at
../../gcc/gcc/passes.c:853
#7  0x1051b248 in execute_pass_list (pass=0x10915e68) at
../../gcc/gcc/passes.c:897
#8  0x1051b274 in execute_pass_list (pass=0x108875bc) at
../../gcc/gcc/passes.c:898
#9  0x100b1684 in tree_rest_of_compilation (fndecl=0xf7862d00) at
../../gcc/gcc/tree-optimize.c:412
#10 0x10016914 in c_expand_body (fndecl=0xf7862d00) at
../../gcc/gcc/c-decl.c:6689
#11 0x1059b894 in cgraph_expand_function (node=0xf75b3e00) at
../../gcc/gcc/cgraphunit.c:1101
#12 0x1059bb24 in cgraph_expand_all_functions () at
../../gcc/gcc/cgraphunit.c:1166
#13 0x1059c718 in cgraph_optimize () at ../../gcc/gcc/cgraphunit.c:1434
#14 0x1001a024 in c_write_global_declarations () at ../../gcc/gcc/c-decl.c:7804
#15 0x104d9928 in compile_file () at ../../gcc/gcc/toplev.c:1012
#16 0x104dbbe4 in do_compile () at ../../gcc/gcc/toplev.c:1957
#17 0x104dbc78 in toplev_main (argc=53, argv=0xff8a9ca4) at
../../gcc/gcc/toplev.c:1989
#18 0x10090518 in main (argc=53, argv=0xff8a9ca4) at ../../gcc/gcc/main.c:35


Moreover, if I add -fdump-tree-vect-details to the above command line, i.e.,
compile recog.c as following:

/Develop/main-110758/build-vect/./prev-gcc/xgcc
-B/Develop/main-110758/build-vect/./prev-gcc/
-B/Develop/main-110758//powerpc64-suse-linux/bin/ -c -O2 -g -ftree-vectorize
-maltivec -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes
-Wmissing-prototypes -pedantic -Wno-long-long -Wno-variadic-macros
-Wno-overlength-strings -Wold-style-definition -Wmissing-format-attribute
-Werror -DHAVE_CONFIG_H -I. -I. -I../../gcc/gcc -I../../gcc/gcc/.
-I../../gcc/gcc/../include -I../../gcc/gcc/../libcpp/include
-I../../gcc/gcc/../libdecnumber -I../libdecnumber -fdump-tree-vect-details
../../gcc/gcc/recog.c

The compilation succeeds.


If I run bootstrap with BOOT_CFLAGS="-O2 -g -ftree-vectorize -maltivec
-fdump-tree-vect-details" (i.e., with dump), -quite and removing
-fdump-tree-vect-details in the command line have no effect on the error I get.
It is always:

../../gcc/gcc/recog.c: In function constrain_operands:
../../gcc/gcc/recog.c:2270: internal compiler error: in mark_operand_necessary,
at tree-ssa-dce.c:266

(see backtrace in comment #9)


So dump and -quite affect compilers behavior. Looks like a memory problem?

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[law at redhat dot com]

------- Comment #16 from law at redhat dot com  2006-11-08 18:29 -------
Subject: Re:  bootstrap comparision fails with
        "-ftree-vectorize -maltivec" on ppc

On Wed, 2006-11-08 at 11:33 +0000, irar at il dot ibm dot com wrote:
> 
> ------- Comment #14 from irar at il dot ibm dot com  2006-11-08 11:33 -------
> (In reply to comment #11)
> >   1. Put a breakpoint in tree_ssa_cd_dce when compiling the
> >      offending function from recog.c.    When that breakpoint
> >      triggers issue:
> >      verify_ssa (true)
> >      I can't see any way for that to fail, but better safe than
> >      sorry.
> 
> It fails...
[ ... ]
> (gdb) p debug_generic_stmt (0xf74510f0)
> #   VUSE <SFT.1940D.29535>;
> #   VUSE <TMT.1945D.29540_551>;
> opD.24623_172 = recog_dataD.15550.operandD.15539[opnoD.24621_29];
> 

Ah.  I had discounted this scenario as I thought this class of
problems had been fixed.

We've got an operand inside a VUSE which was never placed into
SSA form.  This typically occurs when a pass mucks around with
aliasing information.  The vectorizer has been problematical
in this respect.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26197

I think there are links inside that PR which point to other instances
of this underlying problem.

Anyway, what typically happens is the aliasing information gets
mucked up by an early pass, but the affected statements aren't
marked as modified and thus the mucked up aliasing information
isn't exposed until some later pass (typically SSA updates due
to jump threading) marks the statement as modified and rebuilds
the operand cache, exposing the non-SSA operand.  The pass
following jump threading typically core dumps or triggers an
assert like we're seeing in DCE.

Because of the hidden nature of this problem it can be difficult
to determine which pass mucked up the aliasing information.  

I think the easiest way to at least find out what pass is mucking
things up is to insert some code like this at the start of verify_ssa

FOR_EACH_BB (bb)
  for (bsi = bsi_start (bb); ! bsi_end_p (bsi); bsi_next (&bsi))
    update_stmt (bsi_stmt (bsi));

In fact, one could argue that such code really belongs at the
start of verify_ssa permanently.

Hopefully you'll get a checking failure much earlier.  At the least
it'll allow you to look at the dump files for the first reference to
SFT.1940D.29535 that is not in SSA form.

If I had to venture a guess, my money would be on the vectorizer
being the culprit here.

Jeff


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #17 from irar at il dot ibm dot com  2006-11-09 10:15 -------
I applied the patch http://gcc.gnu.org/ml/gcc-patches/2006-07/msg01043.html (a
fix for PR26197). The bootstrap with vectorization passes!

However, the failure in comment #3 still occurs in the later revisions. So, I
am going to hunt for a later patch that broke bootstrap with vectorization
(applying the above patch).

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[janis187 at us dot ibm dot com]

------- Comment #18 from janis187 at us dot ibm dot com  2006-11-09 17:34 -------
Subject: Re:  bootstrap comparision fails with "-ftree-vectorize -maltivec" on
ppc

On Thu, Nov 09, 2006 at 10:15:24AM -0000, irar at il dot ibm dot com wrote:
> However, the failure in comment #3 still occurs in the later revisions. So, I
> am going to hunt for a later patch that broke bootstrap with vectorization
> (applying the above patch).

I can do that with my regression hunt setup, if you'd like; it's set up
to allow adding patches for each new version tested.

Janis


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #19 from irar at il dot ibm dot com  2006-11-12 09:52 -------
Janis,

Thanks a lot!
The range of the revisions is 110758 - 111615 (110758 passes bootstrap with
vectorization with the patch, 111615 fails with the error in comment #3).

I had to modify the patch and split it into two patches in order to make it
possible to apply the patch automatically (without rejections). I am attaching
the two parts.

Thanks,
Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #20 from irar at il dot ibm dot com  2006-11-12 09:55 -------
Created an attachment (id=12597)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12597&action=view)
The first part of the patch


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #21 from irar at il dot ibm dot com  2006-11-12 09:56 -------
Created an attachment (id=12598)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12598&action=view)
The second part of the patch


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[janis at gcc dot gnu dot org]

------- Comment #22 from janis at gcc dot gnu dot org  2006-11-15 22:28 -------
Ira, I keep running into problems with the regression hunt but I'm making
progress.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #23 from irar at il dot ibm dot com  2006-11-20 08:43 -------
Janis, maybe I can help?

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #24 from irar at il dot ibm dot com  2006-11-20 08:46 -------
With the attached patch (max-vect-loops.patch) and flags  
BOOT_CFLAGS="-O2 -g -ftree-vectorize -fno-tree-vect-loop-version -maltivec
--param max-vect-loops=2" 
bootstrap passes on ppc-linux.

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #25 from irar at il dot ibm dot com  2006-11-20 08:50 -------
Created an attachment (id=12649)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12649&action=view)
max-vect-loops.patch

With this patch bootstrap passes with vectorization enabled (with
max-vect-loops = 2)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #26 from irar at il dot ibm dot com  2006-11-20 09:03 -------
I now see the same bootstrap failure on x86 with the patch for vectorization of
strided access. I will try to find the offending loop again, and then I'll try
to compare the generated code before and after the patch (this is orthogonal to
trying to do the same thing on ppc (comment #18)).

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc and i386

[irar at il dot ibm dot com]

------- Comment #27 from irar at il dot ibm dot com  2006-11-22 11:15 -------
I committed the patch that enables vectorization of strided accesses
(http://gcc.gnu.org/ml/gcc-patches/2006-03/msg01679.html), and now bootstrap
with vectorization fails also on x86 with the same error as in comment #3.
Here, the offending loop is cfgloopanal.c:153.

Ira


-- 

irar at il dot ibm dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  GCC build triplet|powerpc64-linux             |powerpc64-linux and and
                   |                            |i386-linux
   GCC host triplet|powerpc64-linux             |powerpc64-linux and i386-
                   |                            |linux
 GCC target triplet|powerpc64-linux             |powerpc64-linux and and
                   |                            |i386-linux
            Summary|bootstrap comparision fails |bootstrap comparision fails
                   |with "-ftree-vectorize -    |with "-ftree-vectorize -
                   |maltivec" on ppc            |maltivec" on ppc and i386


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc and i386

[volodyan at gmail dot com]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1737 bytes --]



------- Comment #28 from volodyan at gmail dot com  2006-12-02 17:46 -------
(In reply to comment #27)
> I committed the patch that enables vectorization of strided accesses


Confirmed the bug on gcc-4.3/(Pentium-M)X86. Configured  as 
../gcc/configure   --enable-bootstrap --enable-languages=c
and built as
make BOOT_CFLAGS="-g   -msse2 -ftree-vectorize -O2" 

Bootstrap failed after wrong execution of the following loop from
cfgloopanal.c/dfs:

  printf("nvert= %d, nq in dfs=%d, post0=%d\n",g->n_vertices, nq, 
g->vertices[0].post);

  for (i = 0; i < g->n_vertices; i++)
    {
      g->vertices[i].component = -1;
      g->vertices[i].post = -1;
    }
 printf("post0=%d; i in dfs=%d\n", g->vertices[0].post, i);
[printf's added by me]

It appears that this loop, which is vectorized according to the vectorizer
dump, doesn't manage to initialize g->vertices[i].post = -1 - the second printf
outputs 0 instead of expected -1 leading to dfs falsely assuming that this
vertex is new and crashing later:

nvert= 10, nq in dfs=8, post0=0
post0=0; i in dfs=10
../../gcc/gcc/crtstuff.c: In function ‘__do_global_dtors_aux’:
../../gcc/gcc/crtstuff.c:265: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
make[3]: *** [crtbegin.o] Error 1
make[3]: Leaving directory `/Develop/mainline/build/gcc'
make[2]: *** [all-stage2-gcc] Error 2
make[2]: Leaving directory `/Develop/mainline/build'
make[1]: *** [stage2-bubble] Error 2
make[1]: Leaving directory `/Develop/mainline/build'
make: *** [all] Error 2
lnx-toshiba:/Develop/mainline/build #


Vladimir 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc and i386

[irar at il dot ibm dot com]

------- Comment #29 from irar at il dot ibm dot com  2006-12-04 09:24 -------
I reproduced the wrong printings on x86. It seems to be a problem in strided
access vectorization after all - no stores are generated. I am looking into
this.

Thanks,
Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc and i386

[irar at il dot ibm dot com]

------- Comment #30 from irar at il dot ibm dot com  2006-12-07 12:14 -------
I am testing a patch for x86 boostrap failure. It was caused by a bug in
vectorization of strided accesses analysis, and, therefore, has nothing to do
with the bootstrap failures on ppc.

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc and i386

[irar at il dot ibm dot com]

------- Comment #31 from irar at il dot ibm dot com  2006-12-07 13:30 -------
(In reply to comment #17)
> I applied the patch http://gcc.gnu.org/ml/gcc-patches/2006-07/msg01043.html (a
> fix for PR26197). The bootstrap with vectorization passes!
> However, the failure in comment #3 still occurs in the later revisions. So, I
> am going to hunt for a later patch that broke bootstrap with vectorization
> (applying the above patch).

I found this patch:
http://gcc.gnu.org/viewcvs?view=rev&revision=110852

The offending loop here is rs6000.c:17088.

If I disable -fmove-loop-invariants on r110852, bootstrap with vectorization
enabled passes.

Ira


-- 

irar at il dot ibm dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rakdver at atrey dot karlin
                   |                            |dot mff dot cuni dot cz


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc and i386

[irar at il dot ibm dot com]

------- Comment #32 from irar at il dot ibm dot com  2006-12-11 12:46 -------
I am attaching the "bad" rs6000.s (generated with vectorization) and "good"
rs6000.s (generated with vectorization and -fno-move-loop-invariants) using
revision 110852 (from February 2006). I looked over these a bit, but I wouldn't
like to hunt down a bug that had since been solved, so I think I'll switch to
looking into more recent snapshots. 

Ira


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc and i386

[irar at il dot ibm dot com]

------- Comment #33 from irar at il dot ibm dot com  2006-12-11 12:57 -------
Created an attachment (id=12779)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12779&action=view)
"Bad" rs6000.s 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc and i386

[irar at il dot ibm dot com]

------- Comment #34 from irar at il dot ibm dot com  2006-12-11 13:02 -------
Created an attachment (id=12781)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=12781&action=view)
"Good" rs6000.s


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[irar at il dot ibm dot com]

------- Comment #35 from irar at il dot ibm dot com  2006-12-14 11:58 -------
Th problem was solved for i386 by
http://gcc.gnu.org/viewcvs?view=rev&revision=119779.

Ira


-- 

irar at il dot ibm dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  GCC build triplet|powerpc64-linux and i386-   |powerpc64-linux
                   |linux                       |
   GCC host triplet|powerpc64-linux and i386-   |powerpc64-linux
                   |linux                       |
 GCC target triplet|powerpc64-linux and i386-   |powerpc64-linux
                   |linux                       |
            Summary|bootstrap comparision fails |bootstrap comparision fails
                   |with "-ftree-vectorize -    |with "-ftree-vectorize -
                   |maltivec" on ppc and i386   |maltivec" on ppc


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752

[Bug middle-end/28752] bootstrap comparision fails with "-ftree-vectorize -maltivec" on ppc

[meissner at gcc dot gnu dot org]

------- Comment #36 from meissner at gcc dot gnu dot org  2010-02-25 04:59 -------
I've tested the current GCC 4.5 development branch and it builds fine now with
BOOT_CFLAGS='-g -O3 -ftree-vectorize -mcpu=power5 -maltivec'.  It also builds
with BOOT_CFLAGS='-g -O3 -ftree-vectorize -mcpu=power7'.  I also built the
current 4.4 branch with altivec, and it bootstrapped fine without problem.

Given this was reported in 2006, I suspect the fixes discussed in the thread
have long since been applied to the compiler.  So, I'm closing the bug.


-- 

meissner at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |meissner at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |WORKSFORME


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28752