https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109071
--- Comment #10 from qinzhao at gcc dot gnu.org ---
with the following added heuristic in array-bound checker:
+ /* If the stmt is duplicated and splitted, the warning level is not 2,
+ and the current block is not dominating the exit block, not report
+ the warning. */
+ if (is_splitted && warn_array_bounds < 2
+ && !is_dominate_exit)
+ return false;
+
such false positive warnings are moved from -Warray-bound=1 to -Warray-bound=2.
[opc@qinzhao-ol8u3-x86 109071]$ /home/opc/Install/latest-d/bin/gcc -O2
-Warray-bounds=2 -c -o t.o t.c
t.c: In function ‘sparx5_set’:
t.c:12:29: warning: array subscript 4 is above array bounds of ‘int[4]’
[-Warray-bounds=]
12 | int *val = &sg->vals[index];
| ~~~~~~~~^~~~~~~
t.c:8:18: note: while referencing ‘vals’
8 | struct nums {int vals[4];};
| ^~~~
[opc@qinzhao-ol8u3-x86 109071]$ /home/opc/Install/latest-d/bin/gcc -O2
-Warray-bounds=1 -c -o t.o t.c
[opc@qinzhao-ol8u3-x86 109071]$
