https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125002
Bug ID: 125002
Summary: shrink-wrap.cc:can_get_prologue accepts jumps that
cannot be redirected
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: amylaar at gcc dot gnu.org
Target Milestone: ---
I observed this problem first in GCC 14 for an out-of-tree target.
RISC-V has in principle the same problem, but it is hidden for the testcase
by rtl-optimization/125001 . See rtl-optimization/98289 for details.
The problematic code is still unchanged in GCC17 , and also the code in
rtl_redirect_edge_and_branch_force that cannot cope with redirecting
a register-indirect branch We could either revert or
amend the 98289 patch to can_get_prologue, to leave EDGE_CROSSING edges
untouched in the HAS_LONG_UNCOND_BRANCH == false case, or, as I did in the
patch attachment of comment 7 of 98289, {make the branch redirection code cope
with
the most common case of label-indirect jumping, and add a test if that is
possible
as well}.
