[PATCH] AArch64 - Add parameter to __mount routine

[PATCH] AArch64 - Add parameter to __mount routine

[Venkataramanan Kumar]

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Hi Maintainers,

Attached is a small patch which adds a parameter to __mcount routine.

We would like to make the compiler pass the "frompc" address from the function
that calls __mcount during profiling.

ref: http://gcc.gnu.org/ml/gcc-patches/2013-08/msg01556.html

This patch is cross tested in ARMV8 foundation model. No new regressions found.

If it is ok, someone please commit on my behalf.

2013-09-15  Venkataramanan Kumar  <venkataramanan.kumar@linaro.org>

        * sysdeps/aarch64/machine-gmon.h (__mcount): Accept parameter and
          pass it to mcount_internal.

regards,
Venkat.

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diff --git a/ports/sysdeps/aarch64/machine-gmon.h b/ports/sysdeps/aarch64/machine-gmon.h
index 4425965..5cc2941 100644
--- a/ports/sysdeps/aarch64/machine-gmon.h
+++ b/ports/sysdeps/aarch64/machine-gmon.h
@@ -16,10 +16,9 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-/* GCC version 2 gives us a perfect magical function to get
-   just the information we need:
-     void *__builtin_return_address (unsigned int N)
-   returns the return address of the frame N frames up.  */
+/* Accept 'frompc' address as argument from the function that calls
+   __mcount for profiling.  Use  __builtin_return_address (0)
+   for the 'selfpc' address.  */
 
 #include <sysdep.h>
 
@@ -28,8 +27,8 @@ static void mcount_internal (u_long frompc, u_long selfpc);
 #define _MCOUNT_DECL(frompc, selfpc) \
 static inline void mcount_internal (u_long frompc, u_long selfpc)
 
-#define MCOUNT \
-void __mcount (void)							      \
-{									      \
-  mcount_internal ((u_long) RETURN_ADDRESS (1), (u_long) RETURN_ADDRESS (0)); \
+#define MCOUNT                                                    \
+void __mcount (void *frompc)                                      \
+{                                                                 \
+  mcount_internal ((u_long) frompc, (u_long) RETURN_ADDRESS (0)); \
 }

Re: [PATCH] AArch64 - Add parameter to __mount routine

[Marcus Shawcroft]

On 15 September 2013 13:45, Venkataramanan Kumar
<venkataramanan.kumar@linaro.org> wrote:
> Hi Maintainers,
>
> Attached is a small patch which adds a parameter to __mcount routine.
>
> We would like to make the compiler pass the "frompc" address from the function
> that calls __mcount during profiling.

This is an ABI change, however, given that there is no functioning
profiling solution using the existing interface I don't think that
such a change is a problem.  Does anyone object?

> ref: http://gcc.gnu.org/ml/gcc-patches/2013-08/msg01556.html
>
> This patch is cross tested in ARMV8 foundation model. No new regressions found.
>
> If it is ok, someone please commit on my behalf.

No regressions is a good start. How did you test the the combined
gcc/glibc patches for profiling are working correctly?

/Marcus

Re: [PATCH] AArch64 - Add parameter to __mount routine

[Venkataramanan Kumar]

Hi marcus,

On 16 September 2013 17:01, Marcus Shawcroft <marcus.shawcroft@gmail.com> wrote:
> On 15 September 2013 13:45, Venkataramanan Kumar
> <venkataramanan.kumar@linaro.org> wrote:
>> Hi Maintainers,
>>
>> Attached is a small patch which adds a parameter to __mcount routine.
>>
>> We would like to make the compiler pass the "frompc" address from the function
>> that calls __mcount during profiling.
>
> This is an ABI change, however, given that there is no functioning
> profiling solution using the existing interface I don't think that
> such a change is a problem.  Does anyone object?
>
>> ref: http://gcc.gnu.org/ml/gcc-patches/2013-08/msg01556.html
>>
>> This patch is cross tested in ARMV8 foundation model. No new regressions found.
>>
>> If it is ok, someone please commit on my behalf.
>
> No regressions is a good start. How did you test the the combined
> gcc/glibc patches for profiling are working correctly?

I am cross compiling some simple tests cases and running them under in
ARMV8 model by invoking the runtime linker.

"/work/builds/gcc-fsf-trunk-patch/sysroot-aarch64-unknown-linux-gnu/lib/ld-linux-aarch64.so.1
--library-path /work/builds/gcc-fsf-trunk-patch/sysroot-aarch64-unknown-linux-gnu/lib64
test.out"

Basically do functional testing for these test cases by checking the
available gprof options.

regards,
Venkat,

Re: [PATCH] AArch64 - Add parameter to __mount routine

[Marcus Shawcroft]

On 15 September 2013 13:45, Venkataramanan Kumar
<venkataramanan.kumar@linaro.org> wrote:
> Hi Maintainers,
>
> Attached is a small patch which adds a parameter to __mcount routine.
>
> We would like to make the compiler pass the "frompc" address from the function
> that calls __mcount during profiling.
>
> ref: http://gcc.gnu.org/ml/gcc-patches/2013-08/msg01556.html
>
> This patch is cross tested in ARMV8 foundation model. No new regressions found.
>
> If it is ok, someone please commit on my behalf.
>
> 2013-09-15  Venkataramanan Kumar  <venkataramanan.kumar@linaro.org>
>
>         * sysdeps/aarch64/machine-gmon.h (__mcount): Accept parameter and
>           pass it to mcount_internal.
>
> regards,
> Venkat.

Venkat, I've committed  your patch.
Thanks /Marcus

Re: [PATCH] AArch64 - Add parameter to __mount routine

[Joseph S. Myers]

On Tue, 24 Sep 2013, Marcus Shawcroft wrote:

> Venkat, I've committed  your patch.

Please remember when committing patches for someone else to use git commit 
--author="Name <email>" so the patch's author is correctly recorded in the 
git logs.

-- 
Joseph S. Myers
joseph@codesourcery.com