[Bug target/66470] New: [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[Bug target/66470] New: [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66470

            Bug ID: 66470
           Summary: [4.8/4.9/5/6 Regression] TLS ICE due to
                    ix86_split_long_move
           Product: gcc
           Version: 5.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

extern __thread unsigned long long a[10];
unsigned long long foo (int b) { return a[b]; }

or

extern __thread struct S { int a, b; } a[10];
struct S foo (int b) { return a[b]; }

ICE on x86_64-linux/i686-linux with -m32, all optimization levels.  This worked
in GCC 3.3.6.
The bug is in ix86_split_long_move, when trying to split:
(insn 7 15 13 2 (set (reg:DI 0 ax [92])
        (mem:DI (plus:SI (plus:SI (mult:SI (reg/v:SI 1 dx [orig:89 b ] [89])
                        (const_int 8 [0x8]))
                    (unspec:SI [
                            (const_int 0 [0])
                        ] UNSPEC_TP))
                (reg:SI 0 ax [91])) [1 a S8 A64])) rh1212265.i:2 85
{*movdi_internal}
     (nil))
which, while offsettable, has collisions == 2 (the MEM uses both dx and ax in
the addressing and loads the ax:dx pair).  The splitter assumes it can just use
a lea, but lea can't support %gs: (UNSPEC_TP).  So, either it has to load from
%gs:0 first, then do lea, or better yet just move UNSPEC_TP part to the
individual memory loads.

[Bug target/66470] [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66470

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-06-09
                 CC|                            |mpolacek at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.

[Bug target/66470] [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66470

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.8.5

[Bug target/66470] [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66470

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 35724
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=35724&action=edit
gcc6-pr66470.patch

Untested fix.

[Bug target/66470] [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66470

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Jun 10 09:12:53 2015
New Revision: 224319

URL: https://gcc.gnu.org/viewcvs?rev=224319&root=gcc&view=rev
Log:
        PR target/66470
        * config/i386/i386.c (ix86_split_long_move): For collisions
        involving direct tls segment refs, move the UNSPEC_TP possibly
        wrapped in ZERO_EXTEND out of the address for lea, to each of
        the memory loads.

        * gcc.dg/tls/pr66470.c: New test.
        * gcc.target/i386/pr66470.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/tls/pr66470.c
    trunk/gcc/testsuite/gcc.target/i386/pr66470.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/testsuite/ChangeLog

[Bug target/66470] [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66470

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Jun 10 09:16:16 2015
New Revision: 224320

URL: https://gcc.gnu.org/viewcvs?rev=224320&root=gcc&view=rev
Log:
        PR target/66470
        * config/i386/i386.c (ix86_split_long_move): For collisions
        involving direct tls segment refs, move the UNSPEC_TP possibly
        wrapped in ZERO_EXTEND out of the address for lea, to each of
        the memory loads.

        * gcc.dg/tls/pr66470.c: New test.
        * gcc.target/i386/pr66470.c: New test.

Added:
    branches/gcc-5-branch/gcc/testsuite/gcc.dg/tls/pr66470.c
    branches/gcc-5-branch/gcc/testsuite/gcc.target/i386/pr66470.c
Modified:
    branches/gcc-5-branch/gcc/ChangeLog
    branches/gcc-5-branch/gcc/config/i386/i386.c
    branches/gcc-5-branch/gcc/testsuite/ChangeLog

[Bug target/66470] [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66470

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Jun 10 09:26:06 2015
New Revision: 224321

URL: https://gcc.gnu.org/viewcvs?rev=224321&root=gcc&view=rev
Log:
        PR target/66470
        * config/i386/i386.c (ix86_split_long_move): For collisions
        involving direct tls segment refs, move the UNSPEC_TP possibly
        wrapped in ZERO_EXTEND out of the address for lea, to each of
        the memory loads.

        * gcc.dg/tls/pr66470.c: New test.
        * gcc.target/i386/pr66470.c: New test.

Added:
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/tls/pr66470.c
    branches/gcc-4_9-branch/gcc/testsuite/gcc.target/i386/pr66470.c
Modified:
    branches/gcc-4_9-branch/gcc/ChangeLog
    branches/gcc-4_9-branch/gcc/config/i386/i386.c
    branches/gcc-4_9-branch/gcc/testsuite/ChangeLog

[Bug target/66470] [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66470

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Jun 10 09:34:21 2015
New Revision: 224322

URL: https://gcc.gnu.org/viewcvs?rev=224322&root=gcc&view=rev
Log:
        PR target/66470
        * config/i386/i386.c (ix86_split_long_move): For collisions
        involving direct tls segment refs, move the UNSPEC_TP possibly
        wrapped in ZERO_EXTEND out of the address for lea, to each of
        the memory loads.

        * gcc.dg/tls/pr66470.c: New test.
        * gcc.target/i386/pr66470.c: New test.

Added:
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/tls/pr66470.c
    branches/gcc-4_8-branch/gcc/testsuite/gcc.target/i386/pr66470.c
Modified:
    branches/gcc-4_8-branch/gcc/ChangeLog
    branches/gcc-4_8-branch/gcc/config/i386/i386.c
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog

[Bug target/66470] [4.8/4.9/5/6 Regression] TLS ICE due to ix86_split_long_move

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66470

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

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

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.