[PATCH, Android] Runtime stack protector enabling for Android target

[Igor Zamyatin]

Hi!

For runtime stack protector enabling on x86 for Android we have to
disable current glibc-based implementation and turn on default one
since bionic doesn't use value from gs:0x14.

Tested in android environment(x86_64-*-linux-android), also
bootstrapped and regtested on x86_64-unknown-linux-gnu and i686-linux.
Ok for trunk?

Thanks,
Igor


ChangeLog:

2012-07-05 Sergey Melnikov <sergey.melnikov@intel.com>

        * config/i386/i386.md (stack_protect_set): Disable the pattern
        for Android since Android libc (bionic) does not provide random
        value for stack protection guard at gs:0x14. Guard value
        will be provided from external symbol (default implementation).
        (stack_protect_set_<mode>): Likewise.
        (stack_protect_test): Likewise.
        (stack_protect_test_<mode>): Likewise.

diff --git a/gcc-4.6/gcc/config/i386/i386.md b/gcc-4.6/gcc/config/i386/i386.md
index b1d7e5e..fe0009d 100644
--- a/gcc-4.6/gcc/config/i386/i386.md
+++ b/gcc-4.6/gcc/config/i386/i386.md
@@ -17955,7 +17955,7 @@
 (define_expand "stack_protect_set"
   [(match_operand 0 "memory_operand" "")
    (match_operand 1 "memory_operand" "")]
-  ""
+  "!ANDROID_DEFAULT"
 {
   rtx (*insn)(rtx, rtx);

@@ -17979,7 +17979,7 @@
 	(unspec:P [(match_operand:P 1 "memory_operand" "m")] UNSPEC_SP_SET))
    (set (match_scratch:P 2 "=&r") (const_int 0))
    (clobber (reg:CC FLAGS_REG))]
-  ""
+  "!ANDROID_DEFAULT"
   "mov{<imodesuffix>}\t{%1, %2|%2, %1}\;mov{<imodesuffix>}\t{%2,
%0|%0, %2}\;xor{l}\t%k2, %k2"
   [(set_attr "type" "multi")])

@@ -17997,7 +17997,7 @@
   [(match_operand 0 "memory_operand" "")
    (match_operand 1 "memory_operand" "")
    (match_operand 2 "" "")]
-  ""
+  "!ANDROID_DEFAULT"
 {
   rtx flags = gen_rtx_REG (CCZmode, FLAGS_REG);

@@ -18027,7 +18027,7 @@
 		     (match_operand:P 2 "memory_operand" "m")]
 		    UNSPEC_SP_TEST))
    (clobber (match_scratch:P 3 "=&r"))]
-  ""
+  "!ANDROID_DEFAULT"
   "mov{<imodesuffix>}\t{%1, %3|%3, %1}\;xor{<imodesuffix>}\t{%2, %3|%3, %2}"
   [(set_attr "type" "multi")])