[Bug target/100316] New: Regression: __clear_cache() does not support NULL-pointer arguments

[Bug target/100316] New: Regression: __clear_cache() does not support NULL-pointer arguments

[christophm30 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100316

            Bug ID: 100316
           Summary: Regression: __clear_cache() does not support
                    NULL-pointer arguments
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: christophm30 at gmail dot com
  Target Milestone: ---

Commit c05ece9 changed __clear_cache () such, that it no longer accepts numeric
values as arguments.

In riscv-pk the following code is used to clear the instruction cache:

  __clear_cache(0, 0);

However, this no longer compiles:

      ../pk/pk.c: In function 'run_loaded_program.constprop':
      ../pk/pk.c:177:3: error: both arguments to '__builtin___clear_cache'
      must be pointers
        177 |   __clear_cache(0, 0);
            |   ^~~~~~~~~~~~~~~~~~~


Also using "NULL" or "(void*)0" does not help.

The corresponding bug ticket for PK can be found here:
  https://github.com/riscv/riscv-pk/issues/239

Is there a chance to loosen the restrictions for the arguments?

[Bug target/100316] Regression: __clear_cache() does not support NULL-pointer arguments

[wilson at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100316

Jim Wilson <wilson at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aoliva at gcc dot gnu.org,
                   |                            |wilson at gcc dot gnu.org

--- Comment #1 from Jim Wilson <wilson at gcc dot gnu.org> ---
Constant addresses are VOIDmode, and it only accepts Pmode and ptr_mode.  It
should accept VOIDmode too.  For instance cse_lookup_mem does this
  addr_mode = GET_MODE (XEXP (x, 0));
  if (addr_mode == VOIDmode)
    addr_mode = Pmode;

This stems from changes that Alexandre Oliva made.  Adding him to the cc list.

[Bug middle-end/100316] [11/12 Regression] __clear_cache() does not support NULL-pointer arguments

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100316

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-10-07
            Summary|Regression: __clear_cache() |[11/12 Regression]
                   |does not support            |__clear_cache() does not
                   |NULL-pointer arguments      |support NULL-pointer
                   |                            |arguments
   Target Milestone|---                         |11.3
             Status|UNCONFIRMED                 |NEW
          Component|target                      |middle-end
           Keywords|                            |rejects-valid
     Ever confirmed|0                           |1

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
.

[Bug middle-end/100316] [11/12 Regression] __clear_cache() does not support NULL-pointer arguments

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100316

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Kito Cheng <kito@gcc.gnu.org>:

https://gcc.gnu.org/g:4e5bc4e4506a7ae7bb88fc925a425652a1da6b2d

commit r12-4281-g4e5bc4e4506a7ae7bb88fc925a425652a1da6b2d
Author: Kito Cheng <kito.cheng@sifive.com>
Date:   Thu Oct 7 16:17:13 2021 +0800

    [PR/target 100316] Allow constant address for __builtin___clear_cache.

    __builtin___clear_cache was able to accept constant address for the
    argument, but it seems no longer accept recently, and it even not
    accept constant address which is hold in variable when optimization is
    enable:

    ```
    void foo3(){
      void *yy = (void*)0x1000;
      __builtin___clear_cache(yy, yy);
    }
    ```

    So this patch make BEGIN and END accept VOIDmode, like cselib_lookup_mem
did per
    Jim Wilson's suggestion.

    ```
    static cselib_val *
    cselib_lookup_mem (rtx x, int create)
    {
      ...
      addr_mode = GET_MODE (XEXP (x, 0));
      if (addr_mode == VOIDmode)
        addr_mode = Pmode;
    ```

    Changes v2 -> v3:
    - Use gcc_assert rather than error, maybe_emit_call_builtin___clear_cache
is
    internal use only, and we already checked the type in other place.

    Changes v1 -> v2:
    - Check is CONST_INT intead of cehck mode, no new testcase, since
      constant value with other type like CONST_DOUBLE will catched by
      front-end.
    e.g.
    Code:
    ```c
    void foo(){
      __builtin___clear_cache(1.11, 0);
    }
    ```
    Error message:
    ```
    clearcache-double.c: In function 'foo':
    clearcache-double.c:2:27: error: incompatible type for argument 1 of
'__builtin___clear_cache'
        2 |   __builtin___clear_cache(1.11, 0);
          |                           ^~~~
          |                           |
          |                           double
    clearcache-double.c:2:27: note: expected 'void *' but argument is of type
'double'
    ```

    gcc/ChangeLog:

            PR target/100316
            * builtins.c (maybe_emit_call_builtin___clear_cache): Allow
            CONST_INT for BEGIN and END, and use gcc_assert rather than
            error.

    gcc/testsuite/ChangeLog:

            PR target/100316
            * gcc.c-torture/compile/pr100316.c: New.

[Bug middle-end/100316] [11/12 Regression] __clear_cache() does not support NULL-pointer arguments

[kito at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100316

Kito Cheng <kito at gcc dot gnu.org> changed:

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

[Bug middle-end/100316] [11/12 Regression] __clear_cache() does not support NULL-pointer arguments

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100316

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Kito Cheng <kito@gcc.gnu.org>:

https://gcc.gnu.org/g:aa827fa170d3e61d17c3daaf4d5008a3c674a005

commit r11-9170-gaa827fa170d3e61d17c3daaf4d5008a3c674a005
Author: Kito Cheng <kito.cheng@sifive.com>
Date:   Thu Oct 7 16:17:13 2021 +0800

    [PR/target 100316] Allow constant address for __builtin___clear_cache.

    __builtin___clear_cache was able to accept constant address for the
    argument, but it seems no longer accept recently, and it even not
    accept constant address which is hold in variable when optimization is
    enable:

    ```
    void foo3(){
      void *yy = (void*)0x1000;
      __builtin___clear_cache(yy, yy);
    }
    ```

    So this patch make BEGIN and END accept VOIDmode, like cselib_lookup_mem
did per
    Jim Wilson's suggestion.

    ```
    static cselib_val *
    cselib_lookup_mem (rtx x, int create)
    {
      ...
      addr_mode = GET_MODE (XEXP (x, 0));
      if (addr_mode == VOIDmode)
        addr_mode = Pmode;
    ```

    Changes v2 -> v3:
    - Use gcc_assert rather than error, maybe_emit_call_builtin___clear_cache
is
    internal use only, and we already checked the type in other place.

    Changes v1 -> v2:
    - Check is CONST_INT intead of cehck mode, no new testcase, since
      constant value with other type like CONST_DOUBLE will catched by
      front-end.
    e.g.
    Code:
    ```c
    void foo(){
      __builtin___clear_cache(1.11, 0);
    }
    ```
    Error message:
    ```
    clearcache-double.c: In function 'foo':
    clearcache-double.c:2:27: error: incompatible type for argument 1 of
'__builtin___clear_cache'
        2 |   __builtin___clear_cache(1.11, 0);
          |                           ^~~~
          |                           |
          |                           double
    clearcache-double.c:2:27: note: expected 'void *' but argument is of type
'double'
    ```

    gcc/ChangeLog:

            PR target/100316
            * builtins.c (maybe_emit_call_builtin___clear_cache): Allow
            CONST_INT for BEGIN and END, and use gcc_assert rather than
            error.

    gcc/testsuite/ChangeLog:

            PR target/100316
            * gcc.c-torture/compile/pr100316.c: New.

    (cherry picked from commit 4e5bc4e4506a7ae7bb88fc925a425652a1da6b2d)

[Bug middle-end/100316] [11/12 Regression] __clear_cache() does not support NULL-pointer arguments

[kito at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100316

Kito Cheng <kito at gcc dot gnu.org> changed:

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

--- Comment #5 from Kito Cheng <kito at gcc dot gnu.org> ---
Fixed are committed to both trunk and gcc-11 branch now :)