[Bug target/107032] ARM: libgcc2.c:2174:1: error: r7 cannot be used in 'asm' here

[clyon at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107032

Christophe Lyon <clyon at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |clyon at gcc dot gnu.org

--- Comment #1 from Christophe Lyon <clyon at gcc dot gnu.org> ---
At quick glance, I think this is caused by the definition of CLEAR_INSN_CACHE
in gcc/config/arm/uclinux-eabi.h:

/* Clear the instruction cache from `beg' to `end'.  This makes an
   inline system call to SYS_cacheflush.  */
#undef CLEAR_INSN_CACHE
#define CLEAR_INSN_CACHE(BEG, END)                                      \
{                                                                       \
  register unsigned long _beg __asm ("a1") = (unsigned long) (BEG);     \
  register unsigned long _end __asm ("a2") = (unsigned long) (END);     \
  register unsigned long _flg __asm ("a3") = 0;                         \
  register unsigned long _scno __asm ("r7") = 0xf0002;                  \
  __asm __volatile ("swi 0x0            @ sys_cacheflush"               \
                    : "=r" (_beg)                                       \
                    : "0" (_beg), "r" (_end), "r" (_flg), "r" (_scno)); \
}

which makes explicit use of r7.

This code has been like that since it was committed in 2007....
So I suspect nobody ever tried to build this configuration.