[Bug rtl-optimization/83459] [8 Regression] ICE: qsort checking failed: qsort comparator non-negative on sorted output: 1 with --param=sched-pressure-algorithm=2

[wilco at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83459

--- Comment #3 from Wilco <wilco at gcc dot gnu.org> ---
Author: wilco
Date: Thu Feb  8 12:29:28 2018
New Revision: 257481

URL: https://gcc.gnu.org/viewcvs?rev=257481&root=gcc&view=rev
Log:
PR84068, PR83459: Fix sort order of SCHED_PRESSURE_MODEL

The comparison function for SCHED_PRESSURE_MODEL is incorrect.  If either
instruction is not in target_bb, the ordering is not well defined.  
Since all instructions outside the target_bb get the highest model_index,
all we need to do is sort on model_index.  If the model_index is the same
we defer to RFS_DEP_COUNT and/or RFS_TIE.

    gcc/
        PR rtl-optimization/84068
        PR rtl-optimization/83459
        * haifa-sched.c (rank_for_schedule): Fix SCHED_PRESSURE_MODEL sorting.

    gcc/testsuite
        PR rtl-optimization/84068
        PR rtl-optimization/83459
        * gcc.dg/pr84068.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr84068.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/haifa-sched.c
    trunk/gcc/testsuite/ChangeLog