[Bug target/105247] [11/12 Regression] IA64: ICE on sqlite-3.38.2: in decompose, at rtl.h:2288 since r11-5271-g4866b2f5db117f

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105247

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:ba2f60499dd4a3bc1bb4e99fa12dda3bc1548519

commit r12-8158-gba2f60499dd4a3bc1bb4e99fa12dda3bc1548519
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Apr 14 13:47:34 2022 +0200

    simplify-rtx: Don't assume shift count has the same mode as the shift
[PR105247]

    The following testcase ICEs on ia64.  It is UB at runtime, but we shouldn't
    ICE on it...
    The problem is that on ia64, the shift count (last operand of ASHIFT etc.)
    is promoted to DImode (using zero-extension), while most other targets
    use much narrower modes (say QImode).  If we try to simplify a shift
    and the shift count is CONST_INT or other VOIDmode integer constant
    which isn't properly sign extended for the first operand's mode
    (in the testcase the shift count is 0xfffffff8U and it is a SImode shift),
    then we ICE during wide_int wop1 = pop1; in the first hunk, INTVAL ==
0xfffffff8U
    is not valid for SImode.  I think in theory we could run into this even
    on other targets, say if they use SImode or HImode shift counts for e.g.
    QImode shifts.  I hope word size is the upper bound of what a reasonable
    target should use, using e.g. multiple registers for the shift count is
    insane, so the following patch if op1 has VOIDmode and int_mode
    is narrower than word uses word_mode for extraction of the value.

    2022-04-14  Jakub Jelinek  <jakub@redhat.com>

            PR target/105247
            * simplify-rtx.cc (simplify_const_binary_operation): For shifts
            or rotates by VOIDmode constant integer shift count use word_mode
            for the operand if int_mode is narrower than word.

            * gcc.c-torture/compile/pr105247.c: New test.