Re: [PATCH-for-10.2 2/2] tcg/tci: Disable Int128 support

[Richard Henderson]

On 12/2/25 14:30, Richard Henderson wrote:
On 12/2/25 10:46, Philippe Mathieu-Daudé wrote:
Disable Int128 on TCI, otherwise build fails:
   In file included from ../../tcg/optimize.c:29:
   In file included from include/tcg/tcg-op-common.h:12:
   In file included from include/exec/helper-proto-common.h:10:
   In file included from include/qemu/atomic128.h:62:
   In file included from host/include/aarch64/host/atomic128-cas.h.inc:16:
   host/include/generic/host/atomic128-cas.h.inc:37:12: error: initializing 
'Int128' (aka 'struct Int128') with an expression of incompatible type '__int128_t' (aka 
'__int128')
      37 |     Int128 old = *ptr_align;
         |            ^     ~~~~~~~~~~
   host/include/generic/host/atomic128-cas.h.inc:39:52: warning: incompatible pointer 
types passing 'Int128 *' (aka 'struct Int128 *') to parameter of type '__int128_t 
*' (aka '__int128 *') [-Wincompatible-pointer-types]
      39 |     while (!__atomic_compare_exchange_n(ptr_align, &old, new, true,
         |                                                    ^~~~
   host/include/generic/host/atomic128-cas.h.inc:39:58: error: passing 'Int128' (aka 
'struct Int128') to parameter of incompatible type '__int128_t' (aka '__int128')
      39 |     while (!__atomic_compare_exchange_n(ptr_align, &old, new, true,
         |                                                          ^~~
   host/include/generic/host/atomic128-cas.h.inc:50:12: error: initializing 
'Int128' (aka 'struct Int128') with an expression of incompatible type '__int128_t' (aka 
'__int128')
      50 |     Int128 old = *ptr_align;
         |            ^     ~~~~~~~~~~
   host/include/generic/host/atomic128-cas.h.inc:52:62: error: invalid operands to 
binary expression ('Int128' (aka 'struct Int128') and 'Int128')
      52 |     while (!__atomic_compare_exchange_n(ptr_align, &old, old & val, 
true,
         |                                                          ~~~ ^ ~~~
   host/include/generic/host/atomic128-cas.h.inc:63:12: error: initializing 
'Int128' (aka 'struct Int128') with an expression of incompatible type '__int128_t' (aka 
'__int128')
      63 |     Int128 old = *ptr_align;
         |            ^     ~~~~~~~~~~
   host/include/generic/host/atomic128-cas.h.inc:65:62: error: invalid operands to 
binary expression ('Int128' (aka 'struct Int128') and 'Int128')
      65 |     while (!__atomic_compare_exchange_n(ptr_align, &old, old | val, 
true,
         |                                                          ~~~ ^ ~~~
   1 warning and 6 errors generated.

Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>

And what of the CONFIG_TCG_INTERPRETER test that already exists in int128.h?

There's got to be more to this than that.

If you disable Int128 entirely, then we can't use 
host/include/generic/host/atomic128-cas.h.inc at all.  The bug is within that header, were 
we need to use Int128Alias more, as we already do for atomic16_cmpxchg.

I'll post a fix.


r~