[Bug d/110514] New: d: accesses immutable arrays using constant index still bounds checked

[Bug d/110514] New: d: accesses immutable arrays using constant index still bounds checked

[ibuclaw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110514

            Bug ID: 110514
           Summary: d: accesses immutable arrays using constant index
                    still bounds checked
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: d
          Assignee: ibuclaw at gdcproject dot org
          Reporter: ibuclaw at gcc dot gnu.org
  Target Milestone: ---

For example:
---
immutable uint[] arr = [1,2,3];

void test()
{
    immutable uint* p = arr.ptr;
    if (arr[0]== p[0] && arr[1] == p[1] && arr[2] == p[2])
        return;
    assert(0);
}
---

Although the size and value of `arr` is known at compile-time, and is
guaranteed to never change at run-time, there are still three calls to
`_d_arrayboundsp` inserted into the program.

[Bug d/110514] d: accesses of immutable arrays using constant index still bounds checked

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110514

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Iain Buclaw <ibuclaw@gcc.gnu.org>:

https://gcc.gnu.org/g:61b1c562f8c703bff045e91257120e42b7fae523

commit r14-2234-g61b1c562f8c703bff045e91257120e42b7fae523
Author: Iain Buclaw <ibuclaw@gdcproject.org>
Date:   Sat Jul 1 23:32:53 2023 +0200

    d: Fix accesses of immutable arrays using constant index still bounds
checked

    Starts setting TREE_READONLY against specific kinds of VAR_DECLs, so
    that the middle-end/optimization passes can more aggressively constant
    fold D code that makes use of `immutable' or `const'.

            PR d/110514

    gcc/d/ChangeLog:

            * decl.cc (get_symbol_decl): Set TREE_READONLY on certain kinds of
            const and immutable variables.
            * expr.cc (ExprVisitor::visit (ArrayLiteralExp *)): Set
TREE_READONLY
            on immutable dynamic array literals.

    gcc/testsuite/ChangeLog:

            * gdc.dg/pr110514a.d: New test.
            * gdc.dg/pr110514b.d: New test.
            * gdc.dg/pr110514c.d: New test.
            * gdc.dg/pr110514d.d: New test.

[Bug d/110514] d: accesses of immutable arrays using constant index still bounds checked

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110514

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Iain Buclaw
<ibuclaw@gcc.gnu.org>:

https://gcc.gnu.org/g:3f43c19d0d40b82ecfd10f277322c1f786bcd76d

commit r13-7519-g3f43c19d0d40b82ecfd10f277322c1f786bcd76d
Author: Iain Buclaw <ibuclaw@gdcproject.org>
Date:   Sat Jul 1 23:32:53 2023 +0200

    d: Fix accesses of immutable arrays using constant index still bounds
checked

    Starts setting TREE_READONLY against specific kinds of VAR_DECLs, so
    that the middle-end/optimization passes can more aggressively constant
    fold D code that makes use of `immutable' or `const'.

            PR d/110514

    gcc/d/ChangeLog:

            * decl.cc (get_symbol_decl): Set TREE_READONLY on certain kinds of
            const and immutable variables.
            * expr.cc (ExprVisitor::visit (ArrayLiteralExp *)): Set
TREE_READONLY
            on immutable dynamic array literals.

    gcc/testsuite/ChangeLog:

            * gdc.dg/pr110514a.d: New test.
            * gdc.dg/pr110514b.d: New test.
            * gdc.dg/pr110514c.d: New test.
            * gdc.dg/pr110514d.d: New test.

    (cherry picked from commit 61b1c562f8c703bff045e91257120e42b7fae523)

[Bug d/110514] d: accesses of immutable arrays using constant index still bounds checked

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110514

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Iain Buclaw
<ibuclaw@gcc.gnu.org>:

https://gcc.gnu.org/g:750526ee180ae2af66ee07db95c9787e8d86ed4b

commit r12-9747-g750526ee180ae2af66ee07db95c9787e8d86ed4b
Author: Iain Buclaw <ibuclaw@gdcproject.org>
Date:   Sat Jul 1 23:32:53 2023 +0200

    d: Fix accesses of immutable arrays using constant index still bounds
checked

    Starts setting TREE_READONLY against specific kinds of VAR_DECLs, so
    that the middle-end/optimization passes can more aggressively constant
    fold D code that makes use of `immutable' or `const'.

            PR d/110514

    gcc/d/ChangeLog:

            * decl.cc (get_symbol_decl): Set TREE_READONLY on certain kinds of
            const and immutable variables.
            * expr.cc (ExprVisitor::visit (ArrayLiteralExp *)): Set
TREE_READONLY
            on immutable dynamic array literals.

    gcc/testsuite/ChangeLog:

            * gdc.dg/pr110514a.d: New test.
            * gdc.dg/pr110514b.d: New test.
            * gdc.dg/pr110514c.d: New test.
            * gdc.dg/pr110514d.d: New test.

    (cherry picked from commit 61b1c562f8c703bff045e91257120e42b7fae523)

[Bug d/110514] d: accesses of immutable arrays using constant index still bounds checked

[ibuclaw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110514

ibuclaw at gcc dot gnu.org changed:

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

--- Comment #4 from ibuclaw at gcc dot gnu.org ---
Fix committed and backported.