2018-04-18 17:28:08

by Colin King

Subject: [PATCH] gpio: make several const arrays static, shrinks object size

From: Colin Ian King <[email protected]>

Don't populate the const read-only arrays 'port' on the stack but
instead make them static. Makes the object code smaller:

Before:
text data bss dec hex filename
8542 4088 672 13302 33f6 drivers/gpio/gpio-gpio-mm.o
10959 4952 832 16743 4167 drivers/gpio/gpio-104-dio-48e.o
9022 5064 1408 15494 3c86 drivers/gpio/gpio-104-idi-48.o

After:
text data bss dec hex filename
8372 4144 672 13188 3384 drivers/gpio/gpio-gpio-mm.o
10790 5008 832 16630 40f6 drivers/gpio/gpio-104-dio-48e.o
8853 5152 1408 15413 3c35 linux/drivers/gpio/gpio-104-idi-48.o

(gcc version 7.2.0 x86_64)

Signed-off-by: Colin Ian King <[email protected]>
---
drivers/gpio/gpio-104-dio-48e.c | 2 +-
drivers/gpio/gpio-104-idi-48.c | 2 +-
drivers/gpio/gpio-gpio-mm.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
index 31e22c93e844..9c4e07fcb74b 100644
--- a/drivers/gpio/gpio-104-dio-48e.c
+++ b/drivers/gpio/gpio-104-dio-48e.c
@@ -188,7 +188,7 @@ static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
size_t i;
- const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
+ static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
const unsigned int gpio_reg_size = 8;
unsigned int bits_offset;
size_t word_index;
diff --git a/drivers/gpio/gpio-104-idi-48.c b/drivers/gpio/gpio-104-idi-48.c
index f35632609379..2c9738adb3a6 100644
--- a/drivers/gpio/gpio-104-idi-48.c
+++ b/drivers/gpio/gpio-104-idi-48.c
@@ -94,7 +94,7 @@ static int idi_48_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
{
struct idi_48_gpio *const idi48gpio = gpiochip_get_data(chip);
size_t i;
- const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
+ static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
const unsigned int gpio_reg_size = 8;
unsigned int bits_offset;
size_t word_index;
diff --git a/drivers/gpio/gpio-gpio-mm.c b/drivers/gpio/gpio-gpio-mm.c
index d496cc56c2a2..b56ff2efbf36 100644
--- a/drivers/gpio/gpio-gpio-mm.c
+++ b/drivers/gpio/gpio-gpio-mm.c
@@ -177,7 +177,7 @@ static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
{
struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
size_t i;
- const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
+ static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
const unsigned int gpio_reg_size = 8;
unsigned int bits_offset;
size_t word_index;
--
2.17.0

2018-04-18 17:42:21

by William Breathitt Gray

Subject: Re: [PATCH] gpio: make several const arrays static, shrinks object size

On Wed, Apr 18, 2018 at 06:26:34PM +0100, Colin King wrote:
>From: Colin Ian King <[email protected]>
>
>Don't populate the const read-only arrays 'port' on the stack but
>instead make them static. Makes the object code smaller:
>
>Before:
> text data bss dec hex filename
> 8542 4088 672 13302 33f6 drivers/gpio/gpio-gpio-mm.o
> 10959 4952 832 16743 4167 drivers/gpio/gpio-104-dio-48e.o
> 9022 5064 1408 15494 3c86 drivers/gpio/gpio-104-idi-48.o
>
>After:
> text data bss dec hex filename
> 8372 4144 672 13188 3384 drivers/gpio/gpio-gpio-mm.o
> 10790 5008 832 16630 40f6 drivers/gpio/gpio-104-dio-48e.o
> 8853 5152 1408 15413 3c35 linux/drivers/gpio/gpio-104-idi-48.o
>
>(gcc version 7.2.0 x86_64)
>
>Signed-off-by: Colin Ian King <[email protected]>

Acked-by: William Breathitt Gray <[email protected]>

2018-04-26 23:04:38

by Linus Walleij

Subject: Re: [PATCH] gpio: make several const arrays static, shrinks object size

On Wed, Apr 18, 2018 at 7:26 PM, Colin King <[email protected]> wrote:

> From: Colin Ian King <[email protected]>
>
> Don't populate the const read-only arrays 'port' on the stack but
> instead make them static. Makes the object code smaller:
>
> Before:
> text data bss dec hex filename
> 8542 4088 672 13302 33f6 drivers/gpio/gpio-gpio-mm.o
> 10959 4952 832 16743 4167 drivers/gpio/gpio-104-dio-48e.o
> 9022 5064 1408 15494 3c86 drivers/gpio/gpio-104-idi-48.o
>
> After:
> text data bss dec hex filename
> 8372 4144 672 13188 3384 drivers/gpio/gpio-gpio-mm.o
> 10790 5008 832 16630 40f6 drivers/gpio/gpio-104-dio-48e.o
> 8853 5152 1408 15413 3c35 linux/drivers/gpio/gpio-104-idi-48.o
>
> (gcc version 7.2.0 x86_64)
>
> Signed-off-by: Colin Ian King <[email protected]>

I had already applied some part of the patch.

Dropped patches to one file for this reason.

Please check the result.

Patch applied!

Yours,
Linus Walleij