mirror of
https://github.com/zephyrproject-rtos/zephyr
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5e23278bab
The bluetooth controller has been using the flag '-Ofast' to keep
within a real-time limit. There are two problems with this; firstly,
when a project should be optimized for size it is standard to use -O2,
not -Ofast.
Secondly, optimization flags have been deemed to be non-portable, so
instead of directly using "-Ofast" we should use the intent-macro
OPTIMIZE_FOR_SPEED_FLAG to ensure toolchain portability.
Testing has shown that we are still within the real-time limit when
changing from -Ofast to -O2. -Ofast is about 1us and 1% faster, but
increases the code size by 13kB (5% of the available flash on a
nRF51).
Since the slowdown is comparatively small compared to the code size
increase we have decided to use -O2 in place of -Ofast.
Other optimization combinations were also measured and their results
can be seen below:
-Ofast in BLE Controller and in #pragma in entropy driver.
Memory region Used Size Region Size %age Used
FLASH: 138920 B 256 KB 52.99%
[bt] [INF] encode_control: l: 6, 6, 7; t: 75, 45, 132.
-O2 in BLE Controller and in #pragma in entropy driver.
Memory region Used Size Region Size %age Used
FLASH: 125840 B 256 KB 48.00%
[bt] [INF] encode_control: l: 6, 6, 7; t: 75, 51, 133
-O3 in BLE Controller and in #pragma in entropy driver.
Memory region Used Size Region Size %age Used
FLASH: 138920 B 256 KB 52.99%
[bt] [INF] encode_control: l: 6, 6, 7; t: 75, 50, 132.
No extra CFLAGS for BLE and entropy driver (pragmas removed), using
CONFIG_SIZE_OPTIMIZATIONS=y
Memory region Used Size Region Size %age Used
FLASH: 120124 B 256 KB 45.82%
[bt] [ERR] isr_rx_conn: assert: '!radio_is_ready()' failed
No extra CFLAGS for BLE and entropy driver (pragmas removed), using
CONFIG_SPEED_OPTIMIZATIONS=y
Memory region Used Size Region Size %age Used
FLASH: 138004 B 256 KB 52.64%
[bt] [INF] encode_control: l: 6, 6, 7; t: 61, 51, 130.
NB: RAM usage differences were insignificant.
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
69 lines
1.0 KiB
CMake
69 lines
1.0 KiB
CMake
zephyr_library()
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zephyr_library_sources(
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util/mem.c
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util/memq.c
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util/mayfly.c
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util/util.c
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ticker/ticker.c
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ll_sw/ll_addr.c
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ll_sw/ll_tx_pwr.c
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ll_sw/ctrl.c
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ll_sw/ll.c
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hci/hci_driver.c
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hci/hci.c
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)
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zephyr_library_sources_ifdef(
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CONFIG_BT_CTLR_CRYPTO
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crypto/crypto.c
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)
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zephyr_library_sources_ifdef(
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CONFIG_BT_BROADCASTER
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ll_sw/ll_adv.c
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)
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zephyr_library_sources_ifdef(
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CONFIG_BT_OBSERVER
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ll_sw/ll_scan.c
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)
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zephyr_library_sources_ifdef(
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CONFIG_BT_CENTRAL
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ll_sw/ll_master.c
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)
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zephyr_library_sources_ifdef(
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CONFIG_BT_CTLR_DTM
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ll_sw/ll_test.c
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)
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zephyr_library_sources_ifdef(
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CONFIG_BT_CTLR_FILTER
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ll_sw/ll_filter.c
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)
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zephyr_library_sources_ifdef(
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CONFIG_SOC_COMPATIBLE_NRF
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hal/nrf5/cntr.c
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hal/nrf5/ecb.c
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hal/nrf5/radio/radio.c
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hal/nrf5/mayfly.c
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hal/nrf5/ticker.c
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)
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zephyr_library_include_directories(
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.
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util
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hal
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ticker
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include
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)
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zephyr_library_compile_options_ifdef(
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CONFIG_BT_CTLR_FAST_ENC
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${OPTIMIZE_FOR_SPEED_FLAG}
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)
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zephyr_library_link_libraries(subsys__bluetooth)
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