[Bug target/95459] New: aarch64: ICE in in aarch64_short_vector_p, at config/aarch64/aarch64.c:16803

[Bug target/95459] New: aarch64: ICE in in aarch64_short_vector_p, at config/aarch64/aarch64.c:16803

[felix.yang at huawei dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95459

            Bug ID: 95459
           Summary: aarch64: ICE in in aarch64_short_vector_p, at
                    config/aarch64/aarch64.c:16803
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: felix.yang at huawei dot com
  Target Milestone: ---
            Target: aarch64

Another sve-related ICE issue triggered under option -mgeneral-regs-only. 

Reduced test case:

#include <arm_sve.h>

svint8x2_t
callee_s8 (svint8_t x0, svint8_t x1)
{
  return svcreate2 (x0, x1);
}

$aarch64-linux-gnu-gcc -O2 -S -mgeneral-regs-only -march=armv8.2-a+sve bar.c

bar.c: In function ‘callee_s8’:
bar.c:6:10: error: ACLE function ‘svcreate2_s8’ is incompatible with the use of
‘-mgeneral-regs-only’
    6 |   return svcreate2 (x0, x1);
      |          ^~~~~~~~~
bar.c:4:1: internal compiler error: in aarch64_short_vector_p, at
config/aarch64/aarch64.c:16803
    4 | callee_s8 (svint8_t x0, svint8_t x1)
      | ^~~~~~~~~
0x17d5887 aarch64_short_vector_p
        ../../gcc-git/gcc/config/aarch64/aarch64.c:16803
0x17d5993 aarch64_composite_type_p
        ../../gcc-git/gcc/config/aarch64/aarch64.c:16838
0x17d5aab aarch64_vfp_is_call_or_return_candidate
        ../../gcc-git/gcc/config/aarch64/aarch64.c:16877
0x17b4a07 aarch64_init_cumulative_args(CUMULATIVE_ARGS*, tree_node const*,
rtx_def*, tree_node const*, unsigned int, bool)
        ../../gcc-git/gcc/config/aarch64/aarch64.c:5988
0xdbf60f assign_parms_initialize_all
        ../../gcc-git/gcc/function.c:2298 0xdc5b8b
gimplify_parameters(gimple**)
        ../../gcc-git/gcc/function.c:3863 0xe86a8b gimplify_body(tree_node*,
bool)
        ../../gcc-git/gcc/gimplify.c:14776
0xe872cf gimplify_function_tree(tree_node*)
        ../../gcc-git/gcc/gimplify.c:14934
0xbe4a4b cgraph_node::analyze()
        ../../gcc-git/gcc/cgraphunit.c:671
0xbe70ef analyze_functions
        ../../gcc-git/gcc/cgraphunit.c:1231
0xbecba3 symbol_table::finalize_compilation_unit()
        ../../gcc-git/gcc/cgraphunit.c:2975

Here, input param 'type' for aarch64_short_vector_p() looks like:

 <record_type 0xffffb236a5e8 svint8x2_t VNx32QI
    size <poly_int_cst 0xffffb2315c20
        type <integer_type 0xffffb22300a8 bitsizetype public unsigned TI
            size <integer_cst 0xffffb221fde0 constant 128>
            unit-size <integer_cst 0xffffb221fdf8 constant 16>
            align:128 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0xffffb22300a8 precision:128 min <integer_cst 0xffffb221fe10 0> max
<integer_cst 0xffffb2229690 0xffffffffffffffffffffffffffffffff>>
        constant
        elt0:  <integer_cst 0xffffb2234108 constant 256> elt1:  <integer_cst
0xffffb2234108 256>>
...

aarch64_short_vector_p() calls aarch64_sve_mode_p() and aarch64_sve_mode_p()
depends on TARGET_SVE which is false under option -mgeneral-regs-only. As a
result, aarch64_sve_mode_p() returns false and this triggers the ICE.  I think
we are simply checking whether a type (and a mode) is a 64/128-bit short vector
or not, TARGET_SVE should not make a difference here.

Proposed patch is trivial:
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c index
7feff77adf6..4f00a8c2063 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -16800,7 +16800,7 @@ aarch64_short_vector_p (const_tree type,
     {
       /* Rely only on the type, not the mode, when processing SVE types.  */
       if (type && aarch64_some_values_include_pst_objects_p (type))
-       gcc_assert (aarch64_sve_mode_p (mode));
+       gcc_assert (TARGET_SVE ? aarch64_sve_mode_p (mode) : true);
       else
        size = GET_MODE_SIZE (mode);
     }

With this fix, we have:
$aarch64-linux-gnu-gcc -O2 -S -mgeneral-regs-only -march=armv8.2-a+sve bar.c

bar.c: In function ‘callee_s8’:
bar.c:6:10: error: ACLE function ‘svcreate2_s8’ is incompatible with the use of
‘-mgeneral-regs-only’
    6 |   return svcreate2 (x0, x1);
      |          ^~~~~~~~~
bar.c:4:1: fatal error: ‘callee_s8’ requires the SVE ISA extension
    4 | callee_s8 (svint8_t x0, svint8_t x1)
      | ^~~~~~~~~
compilation terminated.

[Bug target/95459] aarch64: ICE in in aarch64_short_vector_p, at config/aarch64/aarch64.c:16803

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95459

rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:

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

--- Comment #1 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
(In reply to Fei Yang from comment #0)
> -       gcc_assert (aarch64_sve_mode_p (mode));
> +       gcc_assert (TARGET_SVE ? aarch64_sve_mode_p (mode) : true);

Probably clearer as:

  !TARGET_SVE || aarch64_sve_mode_p (mode)

Might be worth adding a comment like:

  /* Leave later code to report an error if SVE is disabled.  */

[Bug target/95459] aarch64: ICE in aarch64_short_vector_p, at config/aarch64/aarch64.c:16803

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95459

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Sandiford <rsandifo@gcc.gnu.org>:

https://gcc.gnu.org/g:b2672dd630c81513e08829adc63294ffeedf5693

commit r11-833-gb2672dd630c81513e08829adc63294ffeedf5693
Author: Fei Yang <felix.yang@huawei.com>
Date:   Tue Jun 2 18:17:34 2020 +0100

    aarch64: Fix an ICE in aarch64_short_vector_p [PR95459]

    In aarch64_short_vector_p, we are simply checking whether a type (and a
mode)
    is a 64/128-bit short vector or not.  This should not be affected by the
value
    of TARGET_SVE.  Simply leave later code to report an error if SVE is
disabled.

    2020-06-02  Felix Yang  <felix.yang@huawei.com>

    gcc/
            PR target/95459
            * config/aarch64/aarch64.c (aarch64_short_vector_p):
            Leave later code to report an error if SVE is disabled.

    gcc/testsuite/
            PR target/95459
            * gcc.target/aarch64/mgeneral-regs_6.c: New test.

[Bug target/95459] aarch64: ICE in aarch64_short_vector_p, at config/aarch64/aarch64.c:16803

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95459

rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:

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

--- Comment #3 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
Fixed.