[Bug rtl-optimization/80754] [8 Regression][LRA] Invalid smull instruction generated in lra-remat

[wilco at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80754

--- Comment #5 from Wilco <wilco at gcc dot gnu.org> ---
Author: wilco
Date: Wed May 24 17:06:55 2017
New Revision: 248424

URL: https://gcc.gnu.org/viewcvs?rev=248424&root=gcc&view=rev
Log:
When lra-remat rematerializes an instruction with a clobber, it checks
that the clobber does not kill live registers.  However it fails to check
that the clobber also doesn't overlap with the destination register of the
final rematerialized instruction.  As a result it is possible to generate
illegal instructions with the same hard register as the destination and a
clobber.  Fix this by also checking for overlaps with the destination
register.

    gcc/
        PR rtl-optimization/80754
        * lra-remat.c (do_remat): Add overlap checks for dst_regno.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/lra-remat.c