Hi Richi,
> On 29 Jul 2022, at 09:54, Richard Biener via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
>
> The following makes the backward threader reject threads whose entry
> edge is probably never executed according to the profile. That in
> particular, for the testcase, avoids threading the irq == 1 check
> on the path where irq > 31, thereby avoiding spurious -Warray-bounds
> diagnostics
This breaks bootstrap on i686-darwin{9,17} with what looks like a valid
warning (werrors on stage2)
cc1plus … -O2 -Wall … is enough to.
I can repeat it on a cross from x86_64-darwin19, so I can probably reduce the
.ii (it’s like 2M5 raw) and file a PR if you like - depends if the solution
might be obvious to you …
thanks
Iain
--------
In file included from /src-local/gcc-master/gcc/hash-table.h:248,
from /src-local/gcc-master/gcc/coretypes.h:486,
from /src-local/gcc-master/gcc/tree-ssa-threadbackward.cc:22:
In member function ‘T& vec<T, A, vl_embed>::operator[](unsigned int) [with T =
basic_block_def*; A = va_heap]’,
inlined from ‘const T& vec<T>::operator[](unsigned int) const [with T =
basic_block_def*]’ at /src-local/gcc-master/gcc/vec.h:1486:20,
inlined from ‘bool back_threader_profitability::profitable_path_p(const
vec<basic_block_def*>&, tree, edge, bool*)’ at
/src-local/gcc-master/gcc/tree-ssa-threadbackward.cc:781:37:
/src-local/gcc-master/gcc/vec.h:890:19: warning: array subscript 4294967294 is
above array bounds of ‘basic_block_def* [1]’ [-Warray-bounds]
890 | return m_vecdata[ix];
| ~~~~~~~~~^
/src-local/gcc-master/gcc/vec.h: In member function ‘bool
back_threader_profitability::profitable_path_p(const vec<basic_block_def*>&,
tree, edge, bool*)’:
/src-local/gcc-master/gcc/vec.h:635:5: note: while referencing
‘vec<basic_block_def*, va_heap, vl_embed>::m_vecdata’
635 | T m_vecdata[1];
| ^~~~~~~~~
=====
