[Bug tree-optimization/102706] [12 regression] -O2 vectorization causes regression in Warray-bounds-48.c on many targets

[crazylht at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102706

--- Comment #2 from Hongtao.liu <crazylht at gmail dot com> ---
case (2): Part of accesses are inbound, part of accesses are out of bound,
and after vectorization, the warning goes from out of bound line to
inbound line.

>From Wstringop-overflow-2.c:

struct A1 a1_1 = { 0, { 1 } };

void ga1_1 (void)
{
  a1_1.a[0] = 0;
  a1_1.a[1] = 1;                // { dg-warning "\\\[-Wstringop-overflow" }
  a1_1.a[2] = 2;                // { dg-warning "\\\[-Wstringop-overflow" }

  struct A1 a = { 0, { 1 } };   // { dg-warning "\\\[-Wstringop-overflow" "" {
target { i?86-*-* x86_64-*-* } } }
  a.a[0] = 0;
  a.a[1] = 1;                   // { dg-warning "\\\[-Wstringop-overflow" "" {
xfail { i?86-*-* x86_64-*-* } } }
  a.a[2] = 2;                   // { dg-warning "\\\[-Wstringop-overflow" "" {
xfail { i?86-*-* x86_64-*-* } } }
  sink (&a);
}

struct A1 a1i_1 = { 0, { 1 } };

void ga1i_1 (void)
{
  a1i_1.a[0] = 0;
  a1i_1.a[1] = 1;               // { dg-warning "\\\[-Wstringop-overflow" }
  a1i_1.a[2] = 2;               // { dg-warning "\\\[-Wstringop-overflow" }

  // Refer to PR102462
  struct A1 a = { 0, { 1 } };   // { dg-warning "\\\[-Wstringop-overflow" "" {
target { i?86-*-* x86_64-*-* } } }
  a.a[0] = 1;
  a.a[1] = 2;                   // { dg-warning "\\\[-Wstringop-overflow" "" {
xfail { i?86-*-* x86_64-*-* } } }
  a.a[2] = 3;                   // { dg-warning "\\\[-Wstringop-overflow" "" {
xfail { i?86-*-* x86_64-*-* } } }
  sink (&a);
}