llvm dev - Feb 2016 - Is it possible to remove ARM.exidx section?

Hello All,


I've compiled static library (*.a) with Clang3.7 (-target arm-none-eabi)
with -Oz (size very matter for me),
on Ubuntu 14.04
but code size still significant bigger, than produced by GCC 4.8.

In Objdump we can see, that there are .ARM.exidx sections (size of these
sections - 8 bytes),
but GCC-produced code dont have these sections

Also in readelf we can see, that .text section in almost all cases bigger,
than same sections in GCC-produced code

Flags are same (exclude -Os for GCC and -Oz for Clang)
clang -target arm-none-eabi -Oz -ffunction-sections -fdata-sections -c
-nostdinc -isystem ../LIB/include -std=c99 -funsigned-char -mabi=aapcs
-mthumb -MD  -mcpu=cortex-a5 -mfloat-abi=softfp -mfpu=vfpv3-d16 sin.c -o
"LIB/obj/sinl.o"

/usr/bin/arm-none-eabi-gcc -Os -ffunction-sections -fdata-sections -c
-nostdinc -isystem ../LIB/include -std=c99 -funsigned-char -mabi=aapcs
-mthumb -MD  -mcpu=cortex-a5 -mfloat-abi=softfp -mfpu=vfpv3-d16 sin.c -o
"LIB/obj/sinl.o"

Could you please give me some tips, how to reduce size of produced library?
If you need any additional information, please let me know.



Best Regards
Paul
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On 2/10/16 9:48 AM, Pavel Kosov via llvm-dev wrote:
> Hello All,
>
>
> I've compiled static library (*.a) with Clang3.7 (-target
arm-none-eabi)
> with -Oz (size very matter for me),
> on Ubuntu 14.04
> but code size still significant bigger, than produced by GCC 4.8.
>
> In Objdump we can see, that there are .ARM.exidx sections (size of these
> sections - 8 bytes),
> but GCC-produced code dont have these sections
>
> Also in readelf we can see, that .text section in almost all cases bigger,
> than same sections in GCC-produced code
>
> Flags are same (exclude -Os for GCC and -Oz for Clang)
> clang -target arm-none-eabi -Oz -ffunction-sections -fdata-sections -c
> -nostdinc -isystem ../LIB/include -std=c99 -funsigned-char -mabi=aapcs
> -mthumb -MD  -mcpu=cortex-a5 -mfloat-abi=softfp -mfpu=vfpv3-d16 sin.c -o
> "LIB/obj/sinl.o"
>
> /usr/bin/arm-none-eabi-gcc -Os -ffunction-sections -fdata-sections -c
> -nostdinc -isystem ../LIB/include -std=c99 -funsigned-char -mabi=aapcs
> -mthumb -MD  -mcpu=cortex-a5 -mfloat-abi=softfp -mfpu=vfpv3-d16 sin.c -o
> "LIB/obj/sinl.o"
>
> Could you please give me some tips, how to reduce size of produced library?
> If you need any additional information, please let me know.
-fno-exceptions -fno-unwind-tables -Os
>
>
>
> Best Regards
> Paul
>
>
>
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> llvm-dev at lists.llvm.org
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>
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