[Bug target/67995] __attribute__ ((target("arch=XXX"))) enables unsupported ISA

[hjl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67995

--- Comment #3 from hjl at gcc dot gnu.org <hjl at gcc dot gnu.org> ---
Author: hjl
Date: Mon Oct 19 11:18:14 2015
New Revision: 228967

URL: https://gcc.gnu.org/viewcvs?rev=228967&root=gcc&view=rev
Log:
Don't leak ISA to __attribute__ ((target("arch=XXX")))

When processing __attribute__ ((target("arch=XXX"))), we should clear
the ISA bits in x_ix86_isa_flags first to avoid leaking ISA from
command line.

gcc/

        PR target/67995
        * config/i386/i386.c (ix86_valid_target_attribute_tree): If
        arch= is set,  clear all bits in x_ix86_isa_flags, except for
        ISA_64BIT, ABI_64, ABI_X32, and CODE16.

gcc/testsuite/

        PR target/67995
        * gcc.target/i386/pr67995-1.c: New test.
        * gcc.target/i386/pr67995-2.c: Likewise.
        * gcc.target/i386/pr67995-3.c: Likewise.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr67995-1.c
    trunk/gcc/testsuite/gcc.target/i386/pr67995-2.c
    trunk/gcc/testsuite/gcc.target/i386/pr67995-3.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/testsuite/ChangeLog