GCC 12.2.0 warns:
../src/intel/compiler/brw_fs.cpp: In member function ‘bool fs_visitor::
split_virtual_grfs()’:
../src/intel/compiler/brw_fs.cpp:2199:10: warning: ‘void* memset(void*, int,
size_t)’ specified size between 18446744071562067968 and 18446744073709551615
exceeds maximum object size 9223372036854775807 [-Wstringop-overflow=]
2199 | memset(vgrf_has_split, 0, num_vars * sizeof(*vgrf_has_split));
`num_vars` is an `int` but gets assigned the value of `this->alloc.count`,
which is an `unsigned int`. Thus, `num_vars` will be negative if
`this->alloc.count` is larger than int max value. Converting that negative
`int` to a `size_t`, which `memset` expects, then blows it up to a huge
positive value.
Simply turning `num_vars` into an `unsigned int` would be enough to fix this
specific problem, but there are many other instances where an `unsigned int`
gets assigned to an `int` for no good reason in this function. Some of which
the compiler warns about now, some of which it doesn't warn about.
This turns all variables in `fs_visitor::split_virtual_grfs`, which should
reasonably be unsigned, into `unsigned int`s. While at it, a few now pointless
casts are removed.
Reviewed-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19423>
fc00314085