Hi Evandro
On 30/03/15 22:51, Evandro Menezes wrote:
The Samsung Exynos M1 implements the ARMv8 ISA and this patch adds support
for it through the -mcpu command-line option.
The patch was checked on arm-unknown-linux-gnueabihf without new failures.
OK for trunk?
-- Evandro Menezes Austin, TX
0001-ARM-Add-option-for-the-Samsung-Exynos-M1-core-for-AR.patch
diff --git a/gcc/config/arm/arm-cores.def b/gcc/config/arm/arm-cores.def
index b22ea7f..0710a38 100644
--- a/gcc/config/arm/arm-cores.def
+++ b/gcc/config/arm/arm-cores.def
@@ -168,6 +168,7 @@ ARM_CORE("cortex-a17.cortex-a7", cortexa17cortexa7,
cortexa7, 7A, FL_LDSCHED |
ARM_CORE("cortex-a53", cortexa53, cortexa53, 8A, FL_LDSCHED |
FL_CRC32, cortex_a53)
ARM_CORE("cortex-a57", cortexa57, cortexa57, 8A, FL_LDSCHED |
FL_CRC32, cortex_a57)
ARM_CORE("cortex-a72", cortexa72, cortexa57, 8A, FL_LDSCHED |
FL_CRC32, cortex_a57)
+ARM_CORE("exynos-m1", exynosm1, exynosm1, 8A, FL_LDSCHED |
FL_CRC32, exynosm1)
There are two problems with this:
* The 3rd field of ARM_CORE represents the scheduling identifier and
without a
separate pipeline description for exynosm1 this will just use the
generic_sched
scheduler which performs quite poorly on modern cores. Would you prefer to
reuse a pipeline description from one of the pre-existing ones? Look for
example
at the cortex-a72 definition:
ARM_CORE("cortex-a72", cortexa72, cortexa57, <...snip>
here the cortexa57 means 'make scheduling decisions for cortexa57'.
* The final field in ARM_CORE specifies the tuning struct to be used for
this core.
This should be defined in arm.c and have the form 'arm_<ident>_tune, so
for your
case it should be arm_exynosm1_tune. This isn't defined in your patch,
so it won't
compile without that. You can write a custom tuning struct yourself, or
reuse a
tuning struct for one of the existing cores, if you'd like.
Also, you should add exynosm1 to the switch statement in arm_issue_rate
to specify
the issue rate. I have a patch for next stage1 that should refactor it
all into the
tuning structs
(https://gcc.gnu.org/ml/gcc-patches/2014-11/msg02706.html) but until
that goes in, you should fill in the switch statement there.
Thanks,
Kyrill
