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[RFA/ARM][Patch 01/05]: Create tune for Cortex-A15.
- From: Sameera Deshpande <sameera dot deshpande at arm dot com>
- To: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Cc: "nickc at redhat dot com" <nickc at redhat dot com>, Richard Earnshaw <Richard dot Earnshaw at arm dot com>, "paul at codesourcery dot com" <paul at codesourcery dot com>, Ramana Radhakrishnan <Ramana dot Radhakrishnan at arm dot com>
- Date: Tue, 11 Oct 2011 10:15:22 +0100
- Subject: [RFA/ARM][Patch 01/05]: Create tune for Cortex-A15.
- References: <1318324138.2186.40.camel@e102549-lin.cambridge.arm.com>
Hi!
This patch adds new field in tune_params to indicate if LDRD/STRD are
preferred over PUSH/POP in prologue/epilogue of specific core.
It also creates new tune for cortex-A15 and updates tunes for other
cores to set new field to default value.
Changelog entry for Patch to create tune for cortex-a15:
2011-10-11 Sameera Deshpande
<sameera.deshpande@arm.com>
* config/arm/arm-cores.def (cortex_a15): Update.
* config/arm/arm-protos.h (struct tune_params): Add new field...
(arm_gen_ldrd_strd): ... this.
* config/arm/arm.c (arm_slowmul_tune): Add
arm_gen_ldrd_strd field settings.
(arm_fastmul_tune): Likewise.
(arm_strongarm_tune): Likewise.
(arm_xscale_tune): Likewise.
(arm_9e_tune): Likewise.
(arm_v6t2_tune): Likewise.
(arm_cortex_tune): Likewise.
(arm_cortex_a5_tune): Likewise.
(arm_cortex_a9_tune): Likewise.
(arm_fa726te_tune): Likewise.
(arm_cortex_a15_tune): New variable.
--
On Tue, 2011-10-11 at 10:08 +0100, Sameera Deshpande wrote:
> This series of 5 patches generate LDRD/STRD instead of POP/PUSH in
> epilogue/prologue for ARM and Thumb-2 mode of A15.
>
> Patch [1/5] introduces new field in tune which can be used to indicate
> whether LDRD/STRD are preferred over POP/PUSH by the specific core.
>
> Patches [2-5/5] use this field to determine if LDRD/STRD can be
> generated instead of PUSH/POP in ARM and Thumb-2 mode.
>
> Patch [2/5] generates LDRD instead of POP for Thumb-2 epilogue in A15.
> This patch depends on patch [1/5].
>
> Patch [3/5] generates STRD instead of PUSH for Thumb-2 prologue in A15.
> This patch depends for variables, functions and patterns defined in
> [1/5] and [2/5].
>
> Patch [4/5] generates STRD instead of PUSH for ARM prologue in A15. This
> patch depends on [1/5].
>
> Patch [5/5] generates LDRD instead of POP for ARM epilogue in A15. This
> patch depends for variables, functions and patterns defined in [1/5] and
> [4/5].
>
> All these patches depend upon the Thumb2/ARM RTL epilogue patches
> http://gcc.gnu.org/ml/gcc-patches/2011-09/msg01854.html,
> http://gcc.gnu.org/ml/gcc-patches/2011-09/msg01855.html submitted for
> review.
>
> All these patches are applied in given order and tested with check-gcc,
> check-gdb and bootstrap without regression.
>
> In case of ARM mode, significant performance improvement can be seen on
> some parts of a popular embedded consumer benchmark (~26%).
> However, in most of the cases, not much effect is seen on performance.
> (~ 3% improvement)
>
> In case of thumb2, the performance improvement observed on same parts
> the benchmark is ~11% (2.5% improvement).
> diff --git a/gcc/config/arm/arm-cores.def b/gcc/config/arm/arm-cores.def
index 742b5e8..1b42713 100644
--- a/gcc/config/arm/arm-cores.def
+++ b/gcc/config/arm/arm-cores.def
@@ -128,7 +128,7 @@ ARM_CORE("generic-armv7-a", genericv7a, 7A, FL_LDSCHED, cortex)
ARM_CORE("cortex-a5", cortexa5, 7A, FL_LDSCHED, cortex_a5)
ARM_CORE("cortex-a8", cortexa8, 7A, FL_LDSCHED, cortex)
ARM_CORE("cortex-a9", cortexa9, 7A, FL_LDSCHED, cortex_a9)
-ARM_CORE("cortex-a15", cortexa15, 7A, FL_LDSCHED | FL_THUMB_DIV | FL_ARM_DIV, cortex)
+ARM_CORE("cortex-a15", cortexa15, 7A, FL_LDSCHED | FL_THUMB_DIV | FL_ARM_DIV, cortex_a15)
ARM_CORE("cortex-r4", cortexr4, 7R, FL_LDSCHED, cortex)
ARM_CORE("cortex-r4f", cortexr4f, 7R, FL_LDSCHED, cortex)
ARM_CORE("cortex-r5", cortexr5, 7R, FL_LDSCHED | FL_ARM_DIV, cortex)
diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
index f69bc42..c6b8f71 100644
--- a/gcc/config/arm/arm-protos.h
+++ b/gcc/config/arm/arm-protos.h
@@ -243,6 +243,9 @@ struct tune_params
int l1_cache_line_size;
bool prefer_constant_pool;
int (*branch_cost) (bool, bool);
+ /* This flag indicates if STRD/LDRD instructions are preferred
+ over PUSH/POP in epilogue/prologue. */
+ bool prefer_ldrd_strd;
};
extern const struct tune_params *current_tune;
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 6c09267..d709375 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -850,7 +850,8 @@ const struct tune_params arm_slowmul_tune =
5, /* Max cond insns. */
ARM_PREFETCH_NOT_BENEFICIAL,
true, /* Prefer constant pool. */
- arm_default_branch_cost
+ arm_default_branch_cost,
+ false /* Prefer LDRD/STRD. */
};
const struct tune_params arm_fastmul_tune =
@@ -861,7 +862,8 @@ const struct tune_params arm_fastmul_tune =
5, /* Max cond insns. */
ARM_PREFETCH_NOT_BENEFICIAL,
true, /* Prefer constant pool. */
- arm_default_branch_cost
+ arm_default_branch_cost,
+ false /* Prefer LDRD/STRD. */
};
/* StrongARM has early execution of branches, so a sequence that is worth
@@ -875,7 +877,8 @@ const struct tune_params arm_strongarm_tune =
3, /* Max cond insns. */
ARM_PREFETCH_NOT_BENEFICIAL,
true, /* Prefer constant pool. */
- arm_default_branch_cost
+ arm_default_branch_cost,
+ false /* Prefer LDRD/STRD. */
};
const struct tune_params arm_xscale_tune =
@@ -886,7 +889,8 @@ const struct tune_params arm_xscale_tune =
3, /* Max cond insns. */
ARM_PREFETCH_NOT_BENEFICIAL,
true, /* Prefer constant pool. */
- arm_default_branch_cost
+ arm_default_branch_cost,
+ false /* Prefer LDRD/STRD. */
};
const struct tune_params arm_9e_tune =
@@ -897,7 +901,8 @@ const struct tune_params arm_9e_tune =
5, /* Max cond insns. */
ARM_PREFETCH_NOT_BENEFICIAL,
true, /* Prefer constant pool. */
- arm_default_branch_cost
+ arm_default_branch_cost,
+ false /* Prefer LDRD/STRD. */
};
const struct tune_params arm_v6t2_tune =
@@ -908,7 +913,8 @@ const struct tune_params arm_v6t2_tune =
5, /* Max cond insns. */
ARM_PREFETCH_NOT_BENEFICIAL,
false, /* Prefer constant pool. */
- arm_default_branch_cost
+ arm_default_branch_cost,
+ false /* Prefer LDRD/STRD. */
};
/* Generic Cortex tuning. Use more specific tunings if appropriate. */
@@ -920,7 +926,20 @@ const struct tune_params arm_cortex_tune =
5, /* Max cond insns. */
ARM_PREFETCH_NOT_BENEFICIAL,
false, /* Prefer constant pool. */
- arm_default_branch_cost
+ arm_default_branch_cost,
+ false /* Prefer LDRD/STRD. */
+};
+
+const struct tune_params arm_cortex_a15_tune =
+{
+ arm_9e_rtx_costs,
+ NULL,
+ 1, /* Constant limit. */
+ 5, /* Max cond insns. */
+ ARM_PREFETCH_NOT_BENEFICIAL,
+ false, /* Prefer constant pool. */
+ arm_default_branch_cost,
+ true /* Prefer LDRD/STRD. */
};
/* Branches can be dual-issued on Cortex-A5, so conditional execution is
@@ -934,7 +953,8 @@ const struct tune_params arm_cortex_a5_tune =
1, /* Max cond insns. */
ARM_PREFETCH_NOT_BENEFICIAL,
false, /* Prefer constant pool. */
- arm_cortex_a5_branch_cost
+ arm_cortex_a5_branch_cost,
+ false /* Prefer LDRD/STRD. */
};
const struct tune_params arm_cortex_a9_tune =
@@ -945,7 +965,8 @@ const struct tune_params arm_cortex_a9_tune =
5, /* Max cond insns. */
ARM_PREFETCH_BENEFICIAL(4,32,32),
false, /* Prefer constant pool. */
- arm_default_branch_cost
+ arm_default_branch_cost,
+ false /* Prefer LDRD/STRD. */
};
const struct tune_params arm_fa726te_tune =
@@ -956,7 +977,8 @@ const struct tune_params arm_fa726te_tune =
5, /* Max cond insns. */
ARM_PREFETCH_NOT_BENEFICIAL,
true, /* Prefer constant pool. */
- arm_default_branch_cost
+ arm_default_branch_cost,
+ false /* Prefer LDRD/STRD. */
};