On 22/4/25 07:27, Kohei Tokunaga wrote:
Although __builtin___clear_cache is used to flush the instruction cache for
a specified memory region[1], this operation doesn't apply to wasm, as its
memory isn't executable. Moreover, Emscripten does not support this builtin
and fails to compile it with the following error.
fatal error: error in backend: llvm.clear_cache is not supported on wasm
Note, you mix LLVM error ...
To resolve this, this commit removes the call to __builtin___clear_cache for
Emscripten build.
[1]
https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/Other-Builtins.html#index-_005f_005fbuiltin_005f_005f_005fclear_005fcache
... with this GCC documentation:
If the target does not require instruction cache flushes,
__builtin___clear_cache has no effect.
I'd expect __builtin___clear_cache() to be OK, having no effect on a GCC
WASM implementation.
Signed-off-by: Kohei Tokunaga <ktokunaga.m...@gmail.com>
---
include/qemu/cacheflush.h | 7 +++++++
util/cacheflush.c | 4 ++++
2 files changed, 11 insertions(+)
