[Bug rtl-optimization/64287] New: Disable -fuse-caller-save when -pg is active

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64287

            Bug ID: 64287
           Summary: Disable -fuse-caller-save when -pg is active
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vries at gcc dot gnu.org

As discussed in https://gcc.gnu.org/ml/gcc-patches/2014-11/msg01496.html :
...
A problem is detected with building Linux kernel on MIPS platform when
both -fuse-caller-save and -pg options are present. The reason for this
is that -fuse-caller-save relies on the analysis of RTL code, but when
profiling is active (with -pg option) the code is instrumented
by adding a call to mcount function at the beginning of each function.
And this is realized on the most platforms simply by fprintf function,
so this instrumentation is not reflected in RTL code. The result is
that bad code is produced. A solution could be to disable -fuse-caller-save
when -pg is active.
...