Re: [PATCH v6] Enable tracing of pseudo-registers on ARM

Yao Qi
2016-02-26T08:34:20Z

Antoine Tremblay <antoine.tremblay@ericsson.com> writes:

> @@ -20,7 +20,11 @@
> * registers on x86_64.
> */
>

The comments above should be updated as well.

> +#if (defined __x86_64__)
> #include <immintrin.h>
> +#elif (defined __arm__ || defined __thumb2__ || defined __thumb__)

__arm__ is defined even in thumb mode, so only "defined __arm__" is enough.

> +#include <arm_neon.h>

Why do you include arm_neon.h? I don't see anything NEON specific is used.

> +#endif
>
> void
> dummy (void)
> @@ -37,6 +41,7 @@ main (void)
> {
> /* Strictly speaking, it should be ymm15 (xmm15 is 128-bit), but gcc older
> than 4.9 doesn't recognize "ymm15" as a valid register name. */
> +#if (defined __x86_64__)
> register __v8si a asm("xmm15") = {
> 0x12340001,
> 0x12340002,
> @@ -48,6 +53,13 @@ main (void)
> 0x12340008,
> };
> asm volatile ("traceme: call dummy" : : "x" (a));
> +#elif (defined __arm__ || defined __thumb2__ || defined __thumb__)

Only "defined __arm__" is needed.

> + register uint32_t a asm("s5") = {
> + 0x2
> + };

I'd like to write an inline asm to set s5 a value and the value can be shown as
an integer so that the test is more reliable (current test tests float
"2.80259693e-45").

> + asm volatile ("traceme: bl dummy" : : "x" (a));
> +#endif
> +
> end ();
> return 0;
> }
> diff --git a/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.exp b/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.exp
> index 4c52c64..12a2740 100644
> --- a/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.exp
> +++ b/gdb/testsuite/gdb.trace/tracefile-pseudo-reg.exp
> @@ -12,8 +12,8 @@
> # You should have received a copy of the GNU General Public License
> # along with this program. If not, see <http://www.gnu.org/licenses/>.
>
> -if { ! [is_amd64_regs_target] } {
> - verbose "Skipping tfile AVX test (target is not x86_64)."
> +if { ! [is_amd64_regs_target] && ! [istarget "arm*-*-*"] } {
> + verbose "Skipping tracefile pseudo register tests, target is not supported."
> return
> }
>
> @@ -21,8 +21,14 @@ load_lib "trace-support.exp"
>
> standard_testfile
>
> +if { [is_amd64_regs_target] } {
> + set add_flags "-mavx"
> +} elseif { [istarget "arm*-*-*"] } {
> + set add_flags "-mfpu=neon"

Don't have to pass -mfpu=neon, because the case is also valid for vfp.

> +}
> +
> if {[prepare_for_testing $testfile.exp $testfile $srcfile \
> - [list debug additional_flags=-mavx]]} {
> + [list debug additional_flags=$add_flags]]} {
> return -1
> }
>
> @@ -36,20 +42,31 @@ if ![gdb_target_supports_trace] {
> return -1
> }
>
> -gdb_test_multiple "print \$ymm15" "check for AVX support" {
> +if { [is_amd64_regs_target] } {
> + set reg "\$ymm15"
> + set reg_message "check for AVX support"
> +} elseif { [istarget "arm*-*-*"] } {
> + set reg "\$s5"
> + set reg_message "check for Neon support"

$s5 exists on the processors which support NEON or VFP, so the
$reg_message isn't accurate. We can change reg_message to "check
register $reg".

--
Yao (齐尧)