[Bug rtl-optimization/79910] [7 Regression] wrong code with -O -fweb

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79910

--- Comment #5 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Author: law
Date: Fri Mar 17 15:10:13 2017
New Revision: 246226

URL: https://gcc.gnu.org/viewcvs?rev=246226&root=gcc&view=rev
Log:
        PR rtl-optimization/79910
        * combine.c (record_used_regs): New static function.
        (try_combine): Handle situations where there is an additional
        instruction between I2 and I3 which needs to have a LOG_LINK
        updated.

        PR rtl-optimization/79910
        * gcc.dg/torture/pr79910.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/pr79910.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/combine.c
    trunk/gcc/testsuite/ChangeLog