[Bug rtl-optimization/85645] [7/8 Regression] ICE in maybe_record_trace_start, at dwarf2cfi.c:2348

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85645

--- Comment #15 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Author: segher
Date: Tue Jun 26 15:39:02 2018
New Revision: 262155

URL: https://gcc.gnu.org/viewcvs?rev=262155&root=gcc&view=rev
Log:
regrename: Don't rename the dest of a REG_CFA_REGISTER (PR85645)

We should never change the destination of a REG_CFA_REGISTER, just
like for insns with a REG_CFA_RESTORE, because we need to have the
same control flow information on all branches that join.  It is very
doubtful that renaming the scratch registers used for prologue/epilogue
will help anything either.


        Backport from trunk
        2018-05-08  Segher Boessenkool  <segher@kernel.crashing.org>

        PR rtl-optimization/85645
        * regrename.c (build_def_use): Also kill the chains that include the
        destination of a REG_CFA_REGISTER note.

Modified:
    branches/gcc-8-branch/gcc/ChangeLog
    branches/gcc-8-branch/gcc/regrename.c