[gcc r15-11021] testsuite: drop loop optimizations in fstack-protector-strong.c

[Alexandre Oliva]

https://gcc.gnu.org/g:627b38e64831b0347dde62ecb889935141a7bbcb

commit r15-11021-g627b38e64831b0347dde62ecb889935141a7bbcb
Author: Alexandre Oliva <oliva@adacore.com>
Date:   Mon Mar 30 22:18:39 2026 -0300

    testsuite: drop loop optimizations in fstack-protector-strong.c
    
    gcc.dg/fstack-protector-strong.c used to expect one stack_chk_fail per
    function.  When vectorizer improvements caused foo2 to get vectorized
    to the point of enabling the loop and the automatic array-containing
    data structure to be optimized away entirely, it no longer required
    stack protection, and the expected pattern count was decreased.
    
    However, on platforms that don't or can't vectorize the loop, it isn't
    optimized away, and then we find the wrong pattern count.
    
    Reverse the decrease and disable optimizations of the loop that could
    cause it to be optimized out, so that we get the originally-expected
    stack protection everywhere.
    
    
    for  gcc/testsuite/ChangeLog
    
            * gcc.dg/fstack-protector-strong.c (foo2): Prevent loop
            optimizations.  Expect stack protection again.
    
    (cherry picked from commit 04ac40d9d992793d9c76be3aceb4ddc8fb3cc353)

Diff:
---
 gcc/testsuite/gcc.dg/fstack-protector-strong.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.dg/fstack-protector-strong.c b/gcc/testsuite/gcc.dg/fstack-protector-strong.c
index b9f63966b7cc..52485b5252dd 100644
--- a/gcc/testsuite/gcc.dg/fstack-protector-strong.c
+++ b/gcc/testsuite/gcc.dg/fstack-protector-strong.c
@@ -43,6 +43,8 @@ foo2 ()
 {
   struct AA aa;
   int i;
+#pragma GCC novector
+#pragma GCC unroll 0
   for (i = 0; i < 10; ++i)
     {
       aa.as.array[i] = i * (i-1) + i / 2;
@@ -154,4 +156,4 @@ void foo12 ()
   global3 ();
 }
 
-/* { dg-final { scan-assembler-times "stack_chk_fail" 11 } } */
+/* { dg-final { scan-assembler-times "stack_chk_fail" 12 } } */