On Thu, Nov 13, 2014 at 8:59 PM, Jeff Law <l...@redhat.com> wrote:
> On 11/13/14 21:46, H.J. Lu wrote:
>
>>
>> Hi Jeff,
>>
>> I believe the patch is correct. Not all glibcs support IFUNC. It doesn't
>> mean
>> we should disable IFUNC for all glibcs. By default, we do a configure
>> time
>> check for IFUNC. We DO want to use configure time check for IFUNC for
>> Android NDK.
>> I
>
> I'm sorry, I'm objecting to this patch. It is wrong for GCC to produce code
> that is incorrect solely for the benefit of optimizing for a new release of
> a library.
>
> The right way is to trigger the new code on some configure time option or a
> new configuration itself.
>
> Whether or not GCC is doing this right for glibc is irrelevant, the patch is
> _wrong_.
>
I see where the problem is now. For i[34567]86-*-linux* and x86_64-*-linux*
targets, config.gcc assumes modern glibc and enable IFUNC by default.
That is wrong for i[34567]86-*-linux-android* and and x86_64-*-linux-android*
targets. This patch fixes it. The original patch should work with it.
--
H.J.
---
2014-11-13 H.J. Lu <hongjiu...@intel.com>
* config.gcc (default_gnu_indirect_function): Don't assume
modern glibc when targeting Android.
diff --git a/gcc/config.gcc b/gcc/config.gcc
index a6b37d8..1f01a64 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -1404,8 +1404,11 @@ i[34567]86-*-linux* |
i[34567]86-*-kfreebsd*-gnu | i[34567]86-*-knetbsd*-gnu | i
i[34567]86-*-linux*)
tm_file="${tm_file} linux.h linux-android.h"
extra_options="${extra_options} linux-android.opt"
- # Assume modern glibc
- default_gnu_indirect_function=yes
+ # Assume modern glibc unless we are targeting Android
+ case $target in
+ *-*-*android*) ;;
+ *) default_gnu_indirect_function=yes ;;
+ esac
if test x$enable_targets = xall; then
tm_file="${tm_file} i386/x86-64.h i386/gnu-user-common.h
i386/gnu-user64.h i386/linux-common.h i386/linux64.h"
tm_defines="${tm_defines} TARGET_BI_ARCH=1"
@@ -1467,8 +1470,11 @@ x86_64-*-linux* | x86_64-*-kfreebsd*-gnu |
x86_64-*-knetbsd*-gnu)
x86_64-*-linux*)
tm_file="${tm_file} linux.h linux-android.h i386/linux-common.h
i386/linux64.h"
extra_options="${extra_options} linux-android.opt"
- # Assume modern glibc
- default_gnu_indirect_function=yes
+ # Assume modern glibc unless we are targeting Android
+ case $target in
+ *-*-*android*) ;;
+ *) default_gnu_indirect_function=yes ;;
+ esac
;;
x86_64-*-kfreebsd*-gnu)
tm_file="${tm_file} kfreebsd-gnu.h i386/kfreebsd-gnu64.h"
[hjl@gnu-6 gcc]$
