[Bug tree-optimization/94700] New: ICE in forwprop when folding to a VEC_PERM_EXPR

[Bug tree-optimization/94700] New: ICE in forwprop when folding to a VEC_PERM_EXPR

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94700

            Bug ID: 94700
           Summary: ICE in forwprop when folding to a VEC_PERM_EXPR
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rsandifo at gcc dot gnu.org
  Target Milestone: ---

Compiling this with -march=armv8.2-a+sve -msve-vector-bits=256 -O3:

#include <arm_sve.h>

typedef float v8sf __attribute__((vector_size(32)));

svfloat32_t
f (svbool_t pg, svfloat32_t x, svfloat32_t y)
{
  v8sf a = svadd_x (pg, x, 1);
  v8sf b = { a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7] };
  return svdiv_x (pg, b, y);
}

gives:

foo.c: In function ‘svfloat32_t f(svbool_t, svfloat32_t, svfloat32_t)’:         
foo.c:11:1: error: non-trivial conversion in ‘ssa_name’                         
   11 | }                                                                       
      | ^                                                                       
v8sf                                                                            
__SVFloat32_t                                                                   
b_18 = _1;                                                                      
during GIMPLE pass: forwprop                                                    
dump file: foo.031t.forwprop1                                                   

This is the maybe_ident equivalent of PR94683.  I should have
realised at the time that both arms would need fixing.

[Bug tree-optimization/94700] ICE in forwprop when folding to a VEC_PERM_EXPR

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94700

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2020-04-21
             Target|                            |aarch64*-*-*
             Status|UNCONFIRMED                 |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rsandifo at gcc dot gnu.org

--- Comment #1 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
Testing a patch.

[Bug tree-optimization/94700] ICE in forwprop when folding to a VEC_PERM_EXPR

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94700

--- 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:413232a55b960c9b207abf14eea4a8dd247c3e90

commit r10-7870-g413232a55b960c9b207abf14eea4a8dd247c3e90
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Wed Apr 22 11:05:59 2020 +0100

    forwprop: Fix ICE when building an identity constructor [PR94700]

    This is really PR94683 part 2, handling the case in which the vector is
    an identity and so doesn't need a VEC_PERM_EXPR.  I should have realised
    at the time that the other arm of the "if" would need the same fix.

    2020-04-22  Richard Sandiford  <richard.sandiford@arm.com>

    gcc/
            PR tree-optimization/94700
            * tree-ssa-forwprop.c (simplify_vector_constructor): When
processing
            an identity constructor, use a VIEW_CONVERT_EXPR to handle mixtures
            of similarly-structured but distinct vector types.

    gcc/testsuite/
            PR tree-optimization/94700
            * gcc.target/aarch64/sve/acle/general/pr94700.c: New test.

[Bug tree-optimization/94700] ICE in forwprop when folding to a VEC_PERM_EXPR

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94700

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

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

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