[OE-core] [PATCH V2] arch-arm: Do not add -march options for arm architecture along with -mcpu

Mark Hatle mark.hatle at windriver.com
Thu Jan 24 17:08:38 UTC 2019 

On 1/23/19 6:18 PM, Khem Raj wrote:
> tune files which inherit the arch definitions already define appropriate
> -mcpu option, which is equivalent of right -march and -mtune combination
> and is preferred since gcc is getting stricter and stricter with option
> check semantics and can now find incompatible -march and -mcpu options
> better with every release. It does internal feature consistency check
> and if it finds out discrepency between what -mcpu would expand to as
> compared to -march it will flag the options to be incompatible, for
> naked eye it sounds wrong but gcc would translate -mcpu to a given
> -march internally and it might not match to what we set in these arch
> files.
> 
> The effects are quite subtle, where this can result in configure test
> failing to compile due to these incompatible options and a feature
> option getting disabled for a recipe for no reason.
> 
> e.g. with gcc9 which can now detect that -mcpu=cortex-a5 and
> -march=armv7-a are incompatible, many features in libstdc++ ends up
> disabled due to configure check failures e.g. size_t size, ptrdiff_t
> sizes, which inturn results in compiling libstdc++ with unwanted
> disabled features.
> 
> If user has machine definitions which do not inherit the arm tune files
> then they can still use the -march switch as such
> 
> Signed-off-by: Khem Raj <raj.khem at gmail.com>
> ---
> v2: Only delete -march if -mcpu is set
> 
>  meta/conf/machine/include/arm/arch-armv4.inc     | 3 ++-
>  meta/conf/machine/include/arm/arch-armv5.inc     | 3 ++-
>  meta/conf/machine/include/arm/arch-armv6.inc     | 3 ++-
>  meta/conf/machine/include/arm/arch-armv7a.inc    | 3 ++-
>  meta/conf/machine/include/arm/arch-armv7ve.inc   | 3 ++-
>  meta/conf/machine/include/tune-arm1136jf-s.inc   | 2 ++
>  meta/conf/machine/include/tune-arm920t.inc       | 2 ++
>  meta/conf/machine/include/tune-arm926ejs.inc     | 2 ++
>  meta/conf/machine/include/tune-arm9tdmi.inc      | 2 ++
>  meta/conf/machine/include/tune-cortexa15.inc     | 2 ++
>  meta/conf/machine/include/tune-cortexa17.inc     | 2 ++
>  meta/conf/machine/include/tune-cortexa5.inc      | 2 ++
>  meta/conf/machine/include/tune-cortexa7.inc      | 2 ++
>  meta/conf/machine/include/tune-cortexa8.inc      | 2 ++
>  meta/conf/machine/include/tune-cortexa9.inc      | 2 ++
>  meta/conf/machine/include/tune-ep9312.inc        | 4 +++-
>  meta/conf/machine/include/tune-iwmmxt.inc        | 4 +++-
>  meta/conf/machine/include/tune-strongarm1100.inc | 2 ++
>  meta/conf/machine/include/tune-thunderx.inc      | 2 ++
>  meta/conf/machine/include/tune-xscale.inc        | 2 ++
>  20 files changed, 42 insertions(+), 7 deletions(-)
> 
> diff --git a/meta/conf/machine/include/arm/arch-armv4.inc b/meta/conf/machine/include/arm/arch-armv4.inc
> index 47a7ad2830..d31b67623c 100644
> --- a/meta/conf/machine/include/arm/arch-armv4.inc
> +++ b/meta/conf/machine/include/arm/arch-armv4.inc
> @@ -2,7 +2,8 @@ DEFAULTTUNE ?= "armv4"
>  
>  TUNEVALID[arm] = "Enable ARM instruction set"
>  TUNEVALID[armv4] = "Enable instructions for ARMv4"
> -TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv4', ' -march=armv4t', '', d)}"
> +TUNE_MARCH ?= "-march=armv4t"
> +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv4', ' ${TUNE_MARCH}', '', d)}"
>  # enable --fix-v4bx when we have armv4 in TUNE_FEATURES, but then disable it when we have also armv5 or thumb
>  # maybe we should extend bb.utils.contains to support check for any checkvalues in value, now it does 
>  # checkvalues.issubset(val) which cannot be used for negative test of foo neither bar in value
> diff --git a/meta/conf/machine/include/arm/arch-armv5.inc b/meta/conf/machine/include/arm/arch-armv5.inc
> index f9068af9de..868694a44c 100644
> --- a/meta/conf/machine/include/arm/arch-armv5.inc
> +++ b/meta/conf/machine/include/arm/arch-armv5.inc
> @@ -2,7 +2,8 @@ DEFAULTTUNE ?= "armv5"
>  
>  TUNEVALID[armv5] = "Enable instructions for ARMv5"
>  TUNECONFLICTS[armv5] = "armv4"
> -TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv5', ' -march=armv5t${ARMPKGSFX_DSP}', '', d)}"
> +TUNE_MARCH ?= "-march=armv5t${ARMPKGSFX_DSP}"
> +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv5', ' ${TUNE_MARCH}', '', d)}"
>  MACHINEOVERRIDES =. "${@bb.utils.contains('TUNE_FEATURES', 'armv5', 'armv5:', '' ,d)}"

This type of thing won't work, because the TUNE_MARCH could be loaded,
overridden by other components and the order in which the files are loaded.

Add to this multilib configurations, and it becomes a mess to be sure you have
things in the right order, and at 'best' you have to now modify the machine
configurations to try to get the ordering correct.

That is the reason things were implemented the way they were originally.. So if
you choose a particular configuration, you were sure that the arch was set
properly for that system, even if others were loaded and available.


If an march is not compatible with an mcpu value.. these we clearly have a
mismatch.  Where is the mcpu value being defined, and why isn't it in sync with
the march from the CCARGS?

--Mark

>  require conf/machine/include/arm/arch-armv4.inc
> diff --git a/meta/conf/machine/include/arm/arch-armv6.inc b/meta/conf/machine/include/arm/arch-armv6.inc
> index 6c838e999c..e5d3ecec06 100644
> --- a/meta/conf/machine/include/arm/arch-armv6.inc
> +++ b/meta/conf/machine/include/arm/arch-armv6.inc
> @@ -2,7 +2,8 @@ DEFAULTTUNE ?= "armv6hf"
>  
>  TUNEVALID[armv6] = "Enable instructions for ARMv6"
>  TUNECONFLICTS[armv6] = "armv4 armv5"
> -TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv6', ' -march=armv6', '', d)}"
> +TUNE_MARCH ?= "-march=armv6"
> +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv6', ' ${TUNE_MARCH}', '', d)}"
>  MACHINEOVERRIDES =. "${@bb.utils.contains('TUNE_FEATURES', 'armv6', 'armv6:', '' ,d)}"
>  
>  require conf/machine/include/arm/arch-armv5-dsp.inc
> diff --git a/meta/conf/machine/include/arm/arch-armv7a.inc b/meta/conf/machine/include/arm/arch-armv7a.inc
> index a2663d8008..301334dab7 100644
> --- a/meta/conf/machine/include/arm/arch-armv7a.inc
> +++ b/meta/conf/machine/include/arm/arch-armv7a.inc
> @@ -3,7 +3,8 @@ ARM_INSTRUCTION_SET ?= "thumb"
>  
>  TUNEVALID[armv7a] = "Enable instructions for ARMv7-a"
>  TUNECONFLICTS[armv7a] = "armv4 armv5 armv6 armv7"
> -TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7a', ' -march=armv7-a', '', d)}"
> +TUNE_MARCH ?= "-march=armv7-a"
> +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7a', ' ${TUNE_MARCH}', '', d)}"
>  MACHINEOVERRIDES =. "${@bb.utils.contains('TUNE_FEATURES', 'armv7a', 'armv7a:', '' ,d)}"
>  
>  require conf/machine/include/arm/arch-armv6.inc
> diff --git a/meta/conf/machine/include/arm/arch-armv7ve.inc b/meta/conf/machine/include/arm/arch-armv7ve.inc
> index 4d9260fecb..f1f13c17ce 100644
> --- a/meta/conf/machine/include/arm/arch-armv7ve.inc
> +++ b/meta/conf/machine/include/arm/arch-armv7ve.inc
> @@ -2,7 +2,8 @@ DEFAULTTUNE ?= "armv7vethf"
>  
>  TUNEVALID[armv7ve] = "Enable instructions for ARMv7ve"
>  TUNECONFLICTS[armv7ve] = "armv4 armv5 armv6 armv7 armv7a"
> -TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7ve', ' -march=armv7ve', '', d)}"
> +TUNE_MARCH ?= "-march=armv7ve"
> +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'armv7ve', ' ${TUNE_MARCH}', '', d)}"
>  MACHINEOVERRIDES =. "${@bb.utils.contains('TUNE_FEATURES', 'armv7ve', 'armv7ve:', '' ,d)}"
>  
>  require conf/machine/include/arm/arch-armv7a.inc
> diff --git a/meta/conf/machine/include/tune-arm1136jf-s.inc b/meta/conf/machine/include/tune-arm1136jf-s.inc
> index c5de63e1cc..86e3a56119 100644
> --- a/meta/conf/machine/include/tune-arm1136jf-s.inc
> +++ b/meta/conf/machine/include/tune-arm1136jf-s.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv6hf"
>  require conf/machine/include/arm/arch-armv6.inc
>  
>  TUNEVALID[arm1136jfs] = "Enable arm1136jfs specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'arm1136jfs', ' -mcpu=arm1136jf-s', '', d)}"
>  
>  AVAILTUNES += "arm1136jfs"
> diff --git a/meta/conf/machine/include/tune-arm920t.inc b/meta/conf/machine/include/tune-arm920t.inc
> index c6e74b6772..4d65d63bc9 100644
> --- a/meta/conf/machine/include/tune-arm920t.inc
> +++ b/meta/conf/machine/include/tune-arm920t.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv4t"
>  require conf/machine/include/arm/arch-armv4.inc
>  
>  TUNEVALID[arm920t] = "Enable arm920t specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'arm920t', ' -mcpu=arm920t', '', d)}"
>  
>  AVAILTUNES += "arm920t"
> diff --git a/meta/conf/machine/include/tune-arm926ejs.inc b/meta/conf/machine/include/tune-arm926ejs.inc
> index 81bcda339b..9c1bc919ee 100644
> --- a/meta/conf/machine/include/tune-arm926ejs.inc
> +++ b/meta/conf/machine/include/tune-arm926ejs.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv5te"
>  require conf/machine/include/arm/arch-armv5-dsp.inc
>  
>  TUNEVALID[arm926ejs] = "Enable arm926ejs specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'arm926ejs', ' -mcpu=arm926ej-s', '', d)}"
>  
>  AVAILTUNES += "arm926ejs"
> diff --git a/meta/conf/machine/include/tune-arm9tdmi.inc b/meta/conf/machine/include/tune-arm9tdmi.inc
> index e9c2b8fcf5..62c333cce6 100644
> --- a/meta/conf/machine/include/tune-arm9tdmi.inc
> +++ b/meta/conf/machine/include/tune-arm9tdmi.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv4t"
>  require conf/machine/include/arm/arch-armv4.inc
>  
>  TUNEVALID[arm9tdmi] = "Enable arm9tdmi specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'arm9tdmi', ' -mcpu=arm9tdmi', '', d)}"
>  
>  AVAILTUNES += "arm9tdmi"
> diff --git a/meta/conf/machine/include/tune-cortexa15.inc b/meta/conf/machine/include/tune-cortexa15.inc
> index 25e99f93d7..fbef6fee36 100644
> --- a/meta/conf/machine/include/tune-cortexa15.inc
> +++ b/meta/conf/machine/include/tune-cortexa15.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv7vethf-neon"
>  require conf/machine/include/arm/arch-armv7ve.inc
>  
>  TUNEVALID[cortexa15] = "Enable Cortex-A15 specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'cortexa15', ' -mcpu=cortex-a15', '', d)}"
>  
>  # Little Endian base configs
> diff --git a/meta/conf/machine/include/tune-cortexa17.inc b/meta/conf/machine/include/tune-cortexa17.inc
> index 40392f9bcc..92437d05ce 100644
> --- a/meta/conf/machine/include/tune-cortexa17.inc
> +++ b/meta/conf/machine/include/tune-cortexa17.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv7vethf-neon"
>  require conf/machine/include/arm/arch-armv7ve.inc
>  
>  TUNEVALID[cortexa17] = "Enable Cortex-A17 specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'cortexa17', ' -mcpu=cortex-a17', '', d)}"
>  
>  # Little Endian base configs
> diff --git a/meta/conf/machine/include/tune-cortexa5.inc b/meta/conf/machine/include/tune-cortexa5.inc
> index e9eddb407f..f321070072 100644
> --- a/meta/conf/machine/include/tune-cortexa5.inc
> +++ b/meta/conf/machine/include/tune-cortexa5.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv7athf-neon"
>  require conf/machine/include/arm/arch-armv7a.inc
>  
>  TUNEVALID[cortexa5] = "Enable Cortex-A5 specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'cortexa5', ' -mcpu=cortex-a5', '', d)}"
>  
>  # Little Endian base configs
> diff --git a/meta/conf/machine/include/tune-cortexa7.inc b/meta/conf/machine/include/tune-cortexa7.inc
> index 52415d9c8b..ef3fc3f1da 100644
> --- a/meta/conf/machine/include/tune-cortexa7.inc
> +++ b/meta/conf/machine/include/tune-cortexa7.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv7vethf-neon"
>  require conf/machine/include/arm/arch-armv7ve.inc
>  
>  TUNEVALID[cortexa7] = "Enable Cortex-A7 specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'cortexa7', ' -mcpu=cortex-a7', '', d)}"
>  
>  # Little Endian base configs
> diff --git a/meta/conf/machine/include/tune-cortexa8.inc b/meta/conf/machine/include/tune-cortexa8.inc
> index 8ee8de97f1..18e37faeda 100644
> --- a/meta/conf/machine/include/tune-cortexa8.inc
> +++ b/meta/conf/machine/include/tune-cortexa8.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv7athf-neon"
>  require conf/machine/include/arm/arch-armv7a.inc
>  
>  TUNEVALID[cortexa8] = "Enable Cortex-A8 specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'cortexa8', ' -mcpu=cortex-a8', '', d)}"
>  
>  # Little Endian base configs
> diff --git a/meta/conf/machine/include/tune-cortexa9.inc b/meta/conf/machine/include/tune-cortexa9.inc
> index 0cf323c960..af3c93febc 100644
> --- a/meta/conf/machine/include/tune-cortexa9.inc
> +++ b/meta/conf/machine/include/tune-cortexa9.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv7athf-neon"
>  require conf/machine/include/arm/arch-armv7a.inc
>  
>  TUNEVALID[cortexa9] = "Enable Cortex-A9 specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'cortexa9', ' -mcpu=cortex-a9', '', d)}"
>  
>  # Little Endian base configs
> diff --git a/meta/conf/machine/include/tune-ep9312.inc b/meta/conf/machine/include/tune-ep9312.inc
> index 84ca528d6d..fefc8abc66 100644
> --- a/meta/conf/machine/include/tune-ep9312.inc
> +++ b/meta/conf/machine/include/tune-ep9312.inc
> @@ -3,7 +3,9 @@ DEFAULTTUNE ?= "ep9312"
>  require conf/machine/include/arm/arch-armv4.inc
>  
>  TUNEVALID[ep9312] = "Enable Intel PXA27x specific processor optimizations"
> -TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'ep9312', ' -march=ep9312 -mcpu=ep9312', '', d)}"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
> +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'ep9312', ' -mcpu=ep9312', '', d)}"
>  
>  AVAILTUNES += "ep9312"
>  ARMPKGARCH_tune-ep9312 = "ep9312"
> diff --git a/meta/conf/machine/include/tune-iwmmxt.inc b/meta/conf/machine/include/tune-iwmmxt.inc
> index f27423cb2e..3627834e8a 100644
> --- a/meta/conf/machine/include/tune-iwmmxt.inc
> +++ b/meta/conf/machine/include/tune-iwmmxt.inc
> @@ -6,7 +6,9 @@ DEFAULTTUNE ?= "iwmmxt"
>  require conf/machine/include/arm/arch-armv5-dsp.inc
>  
>  TUNEVALID[iwmmxt] = "Enable Intel PXA27x specific processor optimizations"
> -TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'iwmmxt', ' -march=iwmmxt -mcpu=iwmmxt', '', d)}"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
> +TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'iwmmxt', ' -mcpu=iwmmxt', '', d)}"
>  
>  AVAILTUNES += "iwmmxt"
>  ARMPKGARCH_tune-iwmmxt = "iwmmxt"
> diff --git a/meta/conf/machine/include/tune-strongarm1100.inc b/meta/conf/machine/include/tune-strongarm1100.inc
> index 80cfb8ab8a..b111641048 100644
> --- a/meta/conf/machine/include/tune-strongarm1100.inc
> +++ b/meta/conf/machine/include/tune-strongarm1100.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv4"
>  require conf/machine/include/arm/arch-armv4.inc
>  
>  TUNEVALID[strongarm] = "Enable Strongarm 1100 series processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'strongarm', ' -mcpu=strongarm1100', '', d)}"
>  
>  AVAILTUNES += "strongarm"
> diff --git a/meta/conf/machine/include/tune-thunderx.inc b/meta/conf/machine/include/tune-thunderx.inc
> index 3d43b0f7e5..1db579e393 100644
> --- a/meta/conf/machine/include/tune-thunderx.inc
> +++ b/meta/conf/machine/include/tune-thunderx.inc
> @@ -5,6 +5,8 @@ AVAILTUNES += "thunderx thunderx_be"
>  
>  TUNEVALID[thunderx] = "Enable instructions for Cavium ThunderX"
>  
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'thunderx', ' -mcpu=thunderx ', '',d)}"
>  
>  ARMPKGARCH_tune-thunderx ?= "thunderx"
> diff --git a/meta/conf/machine/include/tune-xscale.inc b/meta/conf/machine/include/tune-xscale.inc
> index 0d07333955..ce0a9c5bcc 100644
> --- a/meta/conf/machine/include/tune-xscale.inc
> +++ b/meta/conf/machine/include/tune-xscale.inc
> @@ -3,6 +3,8 @@ DEFAULTTUNE ?= "armv5te"
>  require conf/machine/include/arm/arch-armv5-dsp.inc
>  
>  TUNEVALID[xscale] = "Enable PXA255/PXA26x Xscale specific processor optimizations"
> +# Since we set -mcpu option here, Do not add -march option
> +TUNE_MARCH = ""
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'xscale', ' -mcpu=xscale', '', d)}"
>  
>  AVAILTUNES += "xscale"
>

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