[gcc r15-4336] fold-const: Fix BIT_INSERT_EXPR folding for BYTES_BIG_ENDIAN [PR116997]

[Andre Simoes Dias Vieira via Gcc-cvs]

https://gcc.gnu.org/g:2e30e90a0c2bf8147a6d24854aa653c332c8f84f

commit r15-4336-g2e30e90a0c2bf8147a6d24854aa653c332c8f84f
Author: Andre Vieira <andre.simoesdiasvie...@arm.com>
Date:   Mon Oct 14 16:24:07 2024 +0100

    fold-const: Fix BIT_INSERT_EXPR folding for BYTES_BIG_ENDIAN [PR116997]
    
    Fix constant folding of BIT_INSER_EXPR for BYTES_BIG_ENDIAN targets.
    
    gcc/ChangeLog:
    
            PR middle-end/116997
            * fold-const.cc (fold_ternary_loc): Fix BIT_INSERT_EXPR constant 
folding
            for BYTES_BIG_ENDIAN targets.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.dg/vect/pr116997.c: New test.
    
    Co-authored-by: Andrew Pinski <quic_apin...@quicinc.com>

Diff:
---
 gcc/fold-const.cc                    |  2 ++
 gcc/testsuite/gcc.dg/vect/pr116997.c | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index 0578f42ac0c5..6f73f648b70c 100644
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -13712,6 +13712,8 @@ fold_ternary_loc (location_t loc, enum tree_code code, 
tree type,
        {
          unsigned HOST_WIDE_INT bitpos = tree_to_uhwi (op2);
          unsigned bitsize = TYPE_PRECISION (TREE_TYPE (arg1));
+         if (BYTES_BIG_ENDIAN)
+           bitpos = TYPE_PRECISION (type) - bitpos - bitsize;
          wide_int tem = (wi::to_wide (arg0)
                          & wi::shifted_mask (bitpos, bitsize, true,
                                              TYPE_PRECISION (type)));
diff --git a/gcc/testsuite/gcc.dg/vect/pr116997.c 
b/gcc/testsuite/gcc.dg/vect/pr116997.c
new file mode 100644
index 000000000000..4563fc2bfb6f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr116997.c
@@ -0,0 +1,18 @@
+/* PR 116997.  */
+struct S0
+{
+  unsigned f0;
+  signed f2 : 11;
+  signed : 6;
+} GlobS, *Ptr = &GlobS;
+
+const struct S0 Initializer = {7, 3};
+
+int main (void)
+{
+  for (unsigned i = 0; i <= 2; i++)
+    *Ptr = Initializer;
+  if (GlobS.f2 != 3)
+    __builtin_abort ();
+  return 0;
+}