[Bug c/58400] New: gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[Bug c/58400] New: gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[gang.chen at asianux dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

            Bug ID: 58400
           Summary: gcc for h8300 internal compiler error: insn does not
                    satisfy its constraints at  fs/ext4/mballoc.c: In
                    function 'mb_free_blocks':
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gang.chen at asianux dot com

For Linux kernel next-20130828 version:


The command line:

  /usr/local/bin/h8300-gchen-elf-gcc -Wp,-MD,fs/ext4/.mballoc.o.d  -nostdinc
-isystem /usr/local/lib/gcc/h8300-gchen-elf/4.9.0/include
-I/root/linux-next/arch/h8300/include -Iarch/h8300/include/generated  -Iinclude
-I/root/linux-next/arch/h8300/include/uapi -Iarch/h8300/include/generated/uapi
-I/root/linux-next/include/uapi -Iinclude/generated/uapi -include
/root/linux-next/include/linux/kconfig.h -D__KERNEL__ -Wall -Wundef
-Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common
-Werror-implicit-function-declaration -Wno-format-security
-fno-delete-null-pointer-checks -Os -Wno-maybe-uninitialized -mh -mint32
-fno-builtin -g -D__linux__ -DUTS_SYSNAME=\"uClinux\" -fno-reorder-blocks
-fno-ipa-cp-clone -fno-partial-inlining -Wframe-larger-than=1024
-fno-stack-protector -Wno-unused-but-set-variable -fomit-frame-pointer -g
-femit-struct-debug-baseonly -fno-var-tracking
-fno-inline-functions-called-once -Wdeclaration-after-statement
-Wno-pointer-sign -fno-strict-overflow -fconserve-stack -Werror=implicit-int
-Werror=strict-prototypes -DCC_HAVE_ASM_GOTO   -DMODULE  -D"KBUILD_STR(s)=#s"
-D"KBUILD_BASENAME=KBUILD_STR(mballoc)"  -D"KBUILD_MODNAME=KBUILD_STR(ext4)" -c
-o fs/ext4/.tmp_mballoc.o fs/ext4/mballoc.c


The issue:

fs/ext4/mballoc.c: In function 'mb_free_blocks':
fs/ext4/mballoc.c:1459:1: error: insn does not satisfy its constraints:
 }
 ^
(insn 453 831 454 59 (parallel [
            (set (cc0)
                (compare (zero_extract:SI (zero_extend:SI (mem/c:QI (plus:SI
(reg/f:SI 7 sp)
                                    (const_int 32 [0x20])) [0 %sfp+-20 S1
A32]))
                        (const_int 1 [0x1])
                        (and:SI (reg:SI 5 r5)
                            (const_int 7 [0x7])))
                    (const_int 0 [0])))
            (clobber (scratch:QI))
        ]) fs/ext4/mballoc.c:1322 113 {*tstsi_variable_bit_qi}
     (nil))

[Bug c/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[gang.chen at asianux dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #1 from Chen Gang <gang.chen at asianux dot com> ---
fs/ext4/mballoc.c:1459:1: internal compiler error: in
reload_cse_simplify_operands, at postreload.c:411
0x8e0a95 _fatal_insn(char const*, rtx_def const*, char const*, int, char
const*)
        ../../gcc-4.9.0/gcc/rtl-error.c:109
0x8e0abf _fatal_insn_not_found(rtx_def const*, char const*, int, char const*)
        ../../gcc-4.9.0/gcc/rtl-error.c:120
0x89be7b reload_cse_simplify_operands
        ../../gcc-4.9.0/gcc/postreload.c:411
0x89da9c reload_cse_simplify
        ../../gcc-4.9.0/gcc/postreload.c:181
0x89da9c reload_cse_regs_1
        ../../gcc-4.9.0/gcc/postreload.c:220
0x89deab reload_cse_regs
        ../../gcc-4.9.0/gcc/postreload.c:68
0x89deab rest_of_handle_postreload
        ../../gcc-4.9.0/gcc/postreload.c:2332
0x89deab execute
        ../../gcc-4.9.0/gcc/postreload.c:2368
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
make[2]: *** [fs/ext4/mballoc.o] Error 1
make[1]: *** [fs/ext4] Error 2
make: *** [fs] Error 2


The gcc information:
[root@dhcp122 linux-next]# /usr/local/bin/h8300-gchen-elf-gcc -v
Using built-in specs.
COLLECT_GCC=/usr/local/bin/h8300-gchen-elf-gcc
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/h8300-gchen-elf/4.9.0/lto-wrapper
Target: h8300-gchen-elf
Configured with: ../gcc-4.9.0/configure --without-header --disable-nls
--enable-language=c,c++ --disable-threads --disable-shared --enable-werror=no
target_configargs=enable_vtable_verify=yes --target=h8300-gchen-elf
Thread model: single
gcc version 4.9.0 20130910 (experimental) (GCC)

[Bug c/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[gang.chen at asianux dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #2 from Chen Gang <gang.chen at asianux dot com> ---
For gcc-4.8.0 and gcc-4.7.4, it has this issue too.

[Bug c/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[gang.chen at asianux dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #3 from Chen Gang <gang.chen at asianux dot com> ---
If no opitimization (without -Os), it will be OK.

[Bug c/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[gang.chen at asianux dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #4 from Chen Gang <gang.chen at asianux dot com> ---
Created attachment 30812
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30812&action=edit
the .i file for fs/ext4/mballoc.c (bzip2 compressed)

I put .i file in attachment which need "bzip2 -d" to decompress.

[Bug c/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #6 from Jeffrey A. Law <law at redhat dot com> ---
Reduced testcase:
static __inline__ __attribute__((always_inline))
__attribute__((no_instrument_function)) int test_bit(int nr, const unsigned
long* addr)
{
 return (*((volatile unsigned char *)addr +
               ((nr >> 3) ^ 3)) & (1UL << (nr & 7))) != 0;
}
static inline __attribute__((always_inline))
__attribute__((no_instrument_function)) int test_bit_le(int nr, const void
*addr)
{
 return test_bit(nr ^ ((32 -1) & ~0x7), addr);
}
typedef int ext4_grpblk_t;
struct ext4_group_info {
 unsigned long bb_state;
 ext4_grpblk_t bb_counters[];
};
struct ext4_buddy {
 struct super_block *bd_sb;
 struct ext4_group_info *bd_info;
};
static inline __attribute__((always_inline))
__attribute__((no_instrument_function)) void *mb_correct_addr_and_bit(int *bit,
void *addr)
{
 *bit += ((unsigned long) addr & 3UL) << 3;
 return addr;
}
static inline __attribute__((always_inline))
__attribute__((no_instrument_function)) int mb_test_bit(int bit, void *addr)
{
 addr = mb_correct_addr_and_bit(&bit, addr);
 return test_bit_le(bit, addr);
}
static inline __attribute__((always_inline))
__attribute__((no_instrument_function)) void mb_clear_bit(int bit, void *addr)
{
 addr = mb_correct_addr_and_bit(&bit, addr);
 __clear_bit_le(bit, addr);
}
static inline __attribute__((always_inline))
__attribute__((no_instrument_function)) int mb_buddy_adjust_border(int* bit,
void* bitmap, int side)
{
 if (mb_test_bit(*bit + side, bitmap)) {
  mb_clear_bit(*bit, bitmap);
 }
}
static void mb_buddy_mark_free(struct ext4_buddy *e4b, int first)
{
 int max;
 int order = 1;
 void *buddy = bar ();
 while (buddy) {
  void *buddy2;
   e4b->bd_info->bb_counters[order] += mb_buddy_adjust_border(&first, buddy,
-1);
  order++;
  buddy = buddy2;
 }
}
void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
      int first, int count)
{
 int last = first + count - 1;
 int block;
 struct super_block *sb = e4b->bd_sb;
 block = foo();
 if (!!(block != -1)) 
  mb_regenerate_buddy();
 mb_buddy_mark_free(e4b, first >> 1);
}

[Bug c/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kazu at gcc dot gnu.org,
                   |                            |law at redhat dot com

--- Comment #5 from Jeffrey A. Law <law at redhat dot com> ---
Kazu, you added these patterns many years ago...  Your thoughts would be
appreciated.

Compile the attached code with -O2 -mh -mint32 on the H8 port, using the trunk.

It'll fail due to an insn not matching its constraints problem.


The H8 port has the following insn:

(define_insn_and_split "*tstsi_variable_bit_qi"
  [(set (cc0)
        (compare (zero_extract:SI (zero_extend:SI (match_operand:QI 0
"general_operand_src" "r,U,mn>"))
                                  (const_int 1)
                                  (and:SI (match_operand:SI 1
"register_operand" "r,r,r")
                                          (const_int 7)))
                 (const_int 0)))
   (clobber (match_scratch:QI 2 "=X,X,&r"))]
  "TARGET_H8300H || TARGET_H8300S"
  "@
   btst\\t%w1,%X0
   btst\\t%w1,%X0
   #"
  "&& reload_completed
   && !satisfies_constraint_U (operands[0])"
  [(set (match_dup 2)
        (match_dup 0))
   (parallel [(set (cc0)
                   (compare (zero_extract:SI (zero_extend:SI (match_dup 2))
                                             (const_int 1)
                                             (and:SI (match_dup 1)
                                                     (const_int 7)))
                            (const_int 0)))
              (clobber (scratch:QI))])]
  ""    
  [(set_attr "length" "2,8,10")
   (set_attr "cc" "set_zn,set_zn,set_zn")])


Now assume that operand 0 is initially a pseudo, something like this;

(insn 50 49 51 5 (parallel [
            (set (cc0)
                (compare (zero_extract:SI (zero_extend:SI (reg:QI 37 [ D.1545
]))
                        (const_int 1 [0x1])
                        (and:SI (reg:SI 59 [ D.1543 ])
                            (const_int 7 [0x7])))
                    (const_int 0 [0])))
            (clobber (scratch:QI))
        ]) j.c:36 113 {*tstsi_variable_bit_qi}
     (expr_list:REG_DEAD (reg:SI 59 [ D.1543 ])
        (expr_list:REG_DEAD (reg:QI 37 [ D.1545 ])
            (nil))))


That looks fine and good.  Now assume reg:37 doesn't get a hard reg.  reload
will replace the reg with its equivalent stack slot resulting in:


(insn 50 116 51 5 (parallel [
            (set (cc0)
                (compare (zero_extract:SI (zero_extend:SI (mem/c:QI (plus:SI
(reg/f:SI 6 r6)
                                    (const_int -17 [0xffffffffffffffef])) [7
%sfp+-9 S1 A8]))
                        (const_int 1 [0x1])
                        (and:SI (reg:SI 3 r3)
                            (const_int 7 [0x7])))
                    (const_int 0 [0])))
            (clobber (scratch:QI))
        ]) j.c:36 113 {*tstsi_variable_bit_qi}
     (nil))


Note that the insn no longer matches its strict constraints.  It doesn't match
alternatives 0 or 1 because of operand 0.  It doesn't match alternative 2
because the SCRATCH is not a REG.

I'm guessing you wanted reload to give you a scratch register that you could
use for generating code when operand0 wasn't a suitable source for a single bit
extraction.  You'd then split the insn at insn output time using the scratch
register to effectively reload operand0 yourself?

Note there's another pattern tst_extzv_1_n that has potentially the same
problem.

The fundamental issue is that once reload is done, all insns must always
satisfy their constraints, no exceptions. 

Thoughts on how this is supposed to work?

[Bug c/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-09-13
     Ever confirmed|0                           |1

[Bug c/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #7 from Jeffrey A. Law <law at redhat dot com> ---
*** Bug 58401 has been marked as a duplicate of this bug. ***

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[amylaar at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

Jorn Wolfgang Rennecke <amylaar at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amylaar at gcc dot gnu.org

--- Comment #8 from Jorn Wolfgang Rennecke <amylaar at gcc dot gnu.org> ---
Created attachment 32285
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32285&action=edit
patch made as an example how to debug gcc

here is a patch - not regtested.
you might also consider to put the three non-constriant uses of
[satisfies_constraint_]"U" in predicates.md into a different
constraint /vpredicate.
And delete the unused fix_bit_operand,

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[gang.chen.5i5j at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #9 from Chen Gang <gang.chen.5i5j at gmail dot com> ---
(In reply to Jorn Wolfgang Rennecke from comment #8)
> Created attachment 32285 [details]
> patch made as an example how to debug gcc
> 
> here is a patch - not regtested.
> you might also consider to put the three non-constriant uses of
> [satisfies_constraint_]"U" in predicates.md into a different
> constraint /vpredicate.
> And delete the unused fix_bit_operand,


Is this issue fixed? If need continue to test and analyze, please let me know
(If really need continue, I shall try to finish it within next month)

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[ysato at users dot sourceforge.jp]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

Yoshinori Sato <ysato at users dot sourceforge.jp> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ysato at users dot sourceforge.jp

--- Comment #10 from Yoshinori Sato <ysato at users dot sourceforge.jp> ---
I verified fix problem in this patch.
(4.9.2 and 5.0)

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[gang.chen.5i5j at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

Chen Gang <gang.chen.5i5j at gmail dot com> changed:

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

--- Comment #11 from Chen Gang <gang.chen.5i5j at gmail dot com> ---
(In reply to Yoshinori Sato from comment #10)
> I verified fix problem in this patch.
> (4.9.2 and 5.0)

Thank you for your response. Then I should mark it is as fixed, at present.

If any members find this issue will repeat again in the future, please reopen
it.

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

Jeffrey A. Law <law at redhat dot com> changed:

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

--- Comment #12 from Jeffrey A. Law <law at redhat dot com> ---
Please leave the bug open until a fix is committed to the trunk.

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[gang.chen.5i5j at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #13 from Chen Gang <gang.chen.5i5j at gmail dot com> ---
(In reply to Jeffrey A. Law from comment #12)
> Please leave the bug open until a fix is committed to the trunk.

OK, thanks.

Could any members help to commit the related patch to the trunk? I guess, I am
not the suitable member to do it:

 - I only reported and monitored this issue, but did not analyze it in details,
this issue is fixed by another related members.

 - Either, at present, I have no write right for main branch (I have posted my
assignment paper to FSF in 2015-01-31, I guess, it will reach FSF within
2015-02-28).

Thanks.

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[joern.rennecke at embecosm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #14 from joern.rennecke at embecosm dot com ---
On 2 February 2015 at 19:58, gang.chen.5i5j at gmail dot com
<gcc-bugzilla@gcc.gnu.org> wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400
>
> --- Comment #13 from Chen Gang <gang.chen.5i5j at gmail dot com> ---
> (In reply to Jeffrey A. Law from comment #12)
>> Please leave the bug open until a fix is committed to the trunk.
>
> OK, thanks.
>
> Could any members help to commit the related patch to the trunk? I guess, I am
> not the suitable member to do it:

Has anyone done a full regression test?

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #15 from Jeffrey A. Law <law at redhat dot com> ---
The patch needs to be reviewed.  It's been a long time since I thought about
the _STRICT variants of the REG_OK_ macros and how all that's supposed to work.
 I'll have to read up on their semantics before I can review this patch.

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[gang.chen.5i5j at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

--- Comment #16 from Chen Gang <gang.chen.5i5j at gmail dot com> ---
(In reply to Jeffrey A. Law from comment #15)
> The patch needs to be reviewed.  It's been a long time since I thought about
> the _STRICT variants of the REG_OK_ macros and how all that's supposed to
> work.  I'll have to read up on their semantics before I can review this
> patch.

Can I do anything helpful for this issue, next? If I can, please let me know,
and I shall try.

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

Jeffrey A. Law <law at redhat dot com> changed:

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

--- Comment #18 from Jeffrey A. Law <law at redhat dot com> ---
Joern's fix has been tested and committed to the trunk.

[Bug target/58400] gcc for h8300 internal compiler error: insn does not satisfy its constraints at fs/ext4/mballoc.c: In function 'mb_free_blocks':

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58400

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |lacombar at gmail dot com

--- Comment #19 from Jeffrey A. Law <law at redhat dot com> ---
*** Bug 49877 has been marked as a duplicate of this bug. ***