Help with boost1.74

[Giovanni Mascellani]

Dear Debian ARM people,

last boost1.74 version (1.74.0-12) fails to build on armhf[1], and I
suspect the failure is caused by the switch to GCC 11, because it didn't
happen in the version before (compiled with GCC 10).

[1]
https://buildd.debian.org/status/fetch.php?pkg=boost1.74&arch=armhf&ver=1.74.0-12&stamp=1635842472&raw=0

The problem seems to be this:
---
jump_arm_aapcs_elf_gas.S: Assembler messages:
jump_arm_aapcs_elf_gas.S:57: Error: selected processor does not support
`vstmia sp,{d8-d15}' in ARM mode
jump_arm_aapcs_elf_gas.S:68: Error: selected processor does not support
`vldmia sp,{d8-d15}' in ARM mode
---

I have little knowledge of the ARM architecture: why those instructions
are not valid any more? Or simply they were ignored with GCC 10? They
are gated by these defines:
---
#if (defined(__VFP_FP__) && !defined(__SOFTFP__))
@ save S16-S31
vstmia sp, {d8-d15}
#endif
---

For reference, the failing file is [2].

[2]
https://sources.debian.org/src/boost1.74/1.74.0-12/libs/context/src/asm/jump_arm_aapcs_elf_gas.S/

Thanks for your help, Giovanni.

(please Cc: in replies)
--
Giovanni Mascellani <g.masc...@gmail.com>

[peter green]

On 09/11/2021 19:51, Giovanni Mascellani wrote:
> Dear Debian ARM people,
>
> last boost1.74 version (1.74.0-12) fails to build on armhf[1], and I suspect the failure is caused by the switch to GCC 11, because it didn't happen in the version before (compiled with GCC 10).

IIRC the Debian gcc-11 package takes a different approach to specifying default cpu/fpu,
specifying -march=armv7-a+fp rather than seperate march and mfpu options, I wonder if
this is having an influence somehow.

[Christian Marillat]

On 09 nov. 2021 20:51, Giovanni Mascellani <g...@debian.org> wrote:

> Dear Debian ARM people,
>
> last boost1.74 version (1.74.0-12) fails to build on armhf[1], and I
> suspect the failure is caused by the switch to GCC 11, because it
> didn't happen in the version before (compiled with GCC 10).
>
> [1]
> https://buildd.debian.org/status/fetch.php?pkg=boost1.74&arch=armhf&ver=1.74.0-12&stamp=1635842472&raw=0
>
> The problem seems to be this:
> ---
> jump_arm_aapcs_elf_gas.S: Assembler messages:
> jump_arm_aapcs_elf_gas.S:57: Error: selected processor does not
> support `vstmia sp,{d8-d15}' in ARM mode
> jump_arm_aapcs_elf_gas.S:68: Error: selected processor does not
> support `vldmia sp,{d8-d15}' in ARM mode
> ---

Maybe related to bug #996419 ?

Christian