[Bug c/61925] New: internal error when using vectorization on CPU without SSE

[Bug c/61925] New: internal error when using vectorization on CPU without SSE

[mikulas at artax dot karlin.mff.cuni.cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

            Bug ID: 61925
           Summary: internal error when using vectorization on CPU without
                    SSE
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mikulas at artax dot karlin.mff.cuni.cz
              Host: x86_64-unknown-linux-gnu
            Target: x86_64-unknown-linux-gnu
             Build: x86_64-unknown-linux-gnu

Created attachment 33192
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33192&action=edit
a test case

Compile the attached file with "-O3 -m32 -march=i386". You get an internal
error.

vector.c: In function 'f':
vector.c:4:1: warning: SSE vector return without SSE enabled changes the ABI
[-Wpsabi]
 {
 ^
vector.c:3:38: note: The ABI for passing parameters with 16-byte alignment has
changed in GCC 4.6
 __attribute__((vector_size(16))) int f(__attribute__((vector_size(16))) int a,
__attribute__((vector_size(16))) int b)
                                      ^
vector.c:3:38: warning: SSE vector argument without SSE enabled changes the ABI
[-Wpsabi]
vector.c:5:2: internal compiler error: in convert_move, at expr.c:333
  return a + b;
  ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

[Bug target/61925] [4.8/4.9/5.0 Regression] internal error when using vectorization on CPU without SSE

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-07-27
                 CC|                            |mpolacek at gcc dot gnu.org
   Target Milestone|---                         |4.8.4
            Summary|internal error when using   |[4.8/4.9/5.0 Regression]
                   |vectorization on CPU        |internal error when using
                   |without SSE                 |vectorization on CPU
                   |                            |without SSE
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.  Happens since 4.6.

[Bug target/61925] [4.8/4.9/5.0 Regression] internal error when using vectorization on CPU without SSE

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Started with r162918.

[Bug target/61925] [4.8/4.9/5 Regression] internal error when using vectorization on CPU without SSE

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
I will have a look.

[Bug target/61925] [4.8/4.9/5 Regression] internal error when using vectorization on CPU without SSE

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
On trunk I get

vector.c:6:1: error: unrecognizable insn:
(insn 3 2 4 2 (set (reg/v:TI 101 [ a ])
        (mem/c:TI (plus:SI (reg/f:SI 81 virtual-incoming-args)
                (const_int 16 [0x10])) [1 a+0 S16 A128])) vector.c:4 -1
     (expr_list:REG_EQUIV (mem/c:TI (plus:SI (reg/f:SI 81
virtual-incoming-args)
                (const_int 16 [0x10])) [1 a+0 S16 A128])
        (nil)))

instead.

Reduced testcase for the convert_move ICE on the branches, ICEs at -m32
-march=i386:

#pragma GCC push_options                                                        
#pragma GCC target("sse")                                                       
typedef float __m128 __attribute__ ((__vector_size__ (16), __may_alias__));     
typedef long long __m128i __attribute__ ((__vector_size__ (16),
__may_alias__));
__m128i _mm_castps_si128(__m128 __A) { }                                        
#pragma GCC pop_options                                                         
__attribute__((vector_size(16))) int                                           
f(__attribute__((vector_size(16))) int a,                                 
__attribute__((vector_size(16))) int b)                                       
{                                                                               
  return a + b;                                                                 
}            

this seems to be fixed on trunk.

Reduced testcase for the ICE on trunk, ICEs at -m32 -march=i386:

#pragma GCC push_options                                                        
#pragma GCC target("sse")                                                       
typedef float __m128 __attribute__ ((__vector_size__ (16), __may_alias__));     
extern __inline __m128 __attribute__((__gnu_inline__, __always_inline__,
__artificial__)) _mm_undefined_ps (void) {                                      
  }                                                                             
#pragma GCC target("sse2")
#pragma GCC pop_options                                                         
__attribute__((vector_size(16))) int f(__attribute__((vector_size(16))) int a,
__attribute__((vector_size(16))) int b) {                                       
   return a + b;                                                                
  }           

thus it requires a sse2 target attribute.

Would be interesting to know what fixed the convert_move ICE on trunk.

[Bug target/61925] [4.8/4.9/5 Regression] internal error when using vectorization on CPU without SSE

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.4                       |4.8.5

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.4 has been released.

[Bug target/61925] [4.8/4.9/5 Regression] internal error when using vectorization on CPU without SSE

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

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

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

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The first testcase in #c4 got fixed with r217633.

[Bug target/61925] [4.8/4.9/5 Regression] internal error when using vectorization on CPU without SSE

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
So, it seems this is a complete mess.
The reason why we ICE is that the target pragma support is broken.

The main issue I see is that ix86_reset_to_default_globals doesn't actually
reset to defaults (== target_option_default_node), but to the current target
pragma (== target_option_current_node), and that even only if
ix86_previous_fndecl was previously non-NULL and had non-NULL target specific
option.  And then ix86_set_current_function for some strange reason special
cases the defaults (i.e. NULL or == target_option_default_node), both for the
old and new, rather than the current target pragma (==
target_option_current_node).  So, the important question is, is there any
reason
why in between functions the target options (both in global_options and target
globals) should be set to something other than the defaults (==
target_option_default_node)?  I mean, it is hard to guess in what state it is
anyway, as ix86_set_current_function when going to NULL will keep it at the
latest state, so say __attribute__((target (avx2))) function definition in
a #pragma GCC target ("avx") region will keep it in avx2 state afterwards
anyway.
Also, I wonder about the start of
ix86_pragma_target_parse, shouldn't prev_tree be set to
target_option_current_node rather than whatever happens to be in global_options
at that point?
Or is keeping global_options to match the current active target pragma needed
for say vector type modes?  If yes, then we should arrange for
target_option_current_node != target_option_default_node case that whenever we
ix86_set_current_function to NULL, we also restore global_options to that.

And there is another thing - I've noticed nested
ix86_valid_target_attribute_tree calls, the thing is when we are in pragma
target, decl_attributes call this function again, and that happens even when
calling ix86_add_new_builtins from this function.  I wonder if we shouldn't
temporarily clear current_target_pragma, I think the target builtin decls don't
really need that and if pragma GCC target isn't used (but target attribute
instead), it isn't done anyway.

[Bug target/61925] [4.8/4.9/5 Regression] internal error when using vectorization on CPU without SSE

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|rguenth at gcc dot gnu.org         |jakub at gcc dot gnu.org

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 34608
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34608&action=edit
gcc5-pr61925.patch

Untested fix that keeps the current #pragma GCC target options in
global_options if outside of functions.  Passed make check-gcc \
RUNTESTFLAGS='--target_board=unix\{-m32,-m64\} i386.exp'
so far.

[Bug target/61925] [4.8/4.9/5 Regression] internal error when using vectorization on CPU without SSE

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Wed Feb 11 10:04:14 2015
New Revision: 220609

URL: https://gcc.gnu.org/viewcvs?rev=220609&root=gcc&view=rev
Log:
    PR target/61925
    * config/i386/i386.c (ix86_reset_to_default_globals): Removed.
    (ix86_reset_previous_fndecl): Restore it here, unconditionally.
    (ix86_set_current_function): Rewritten.
    (ix86_add_new_builtins): Temporarily clear current_target_pragma
    when creating builtin fndecls.

    * gcc.target/i386/pr61925-1.c: New test.
    * gcc.target/i386/pr61925-2.c: New test.
    * gcc.target/i386/pr61925-3.c: New test.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr61925-1.c
    trunk/gcc/testsuite/gcc.target/i386/pr61925-2.c
    trunk/gcc/testsuite/gcc.target/i386/pr61925-3.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/testsuite/ChangeLog

[Bug target/61925] [4.8/4.9 Regression] internal error when using vectorization on CPU without SSE

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.8/4.9/5 Regression]      |[4.8/4.9 Regression]
                   |internal error when using   |internal error when using
                   |vectorization on CPU        |vectorization on CPU
                   |without SSE                 |without SSE

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed on the trunk so far.

[Bug target/61925] [4.8/4.9 Regression] internal error when using vectorization on CPU without SSE

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.5                       |4.9.3

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
The gcc-4_8-branch is being closed, re-targeting regressions to 4.9.3.

[Bug target/61925] [4.9 Regression] internal error when using vectorization on CPU without SSE

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.9.3 has been released.

[Bug target/61925] [4.9 Regression] internal error when using vectorization on CPU without SSE

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.9.3                       |4.9.4

[Bug target/61925] [4.9 Regression] internal error when using vectorization on CPU without SSE

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61925

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |zsojka at seznam dot cz

--- Comment #14 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 59683 has been marked as a duplicate of this bug. ***