[gcc r16-4046] Widen-Mul: Fix typo assignment in build_and_insert_cast [PR122031]

[Pan Li via Gcc-cvs]

https://gcc.gnu.org/g:5756c9816ed4481d12480b620fb44f0cbbf1e4ad

commit r16-4046-g5756c9816ed4481d12480b620fb44f0cbbf1e4ad
Author: Pan Li <pan2...@intel.com>
Date:   Tue Sep 23 09:51:14 2025 +0800

    Widen-Mul: Fix typo assignment in build_and_insert_cast [PR122031]
    
    The previous fix for PR122021 introduces a typo that the assignment
    to the var itself.  This PR would like to fix the typo, and sorry for
    my silly mistake.
    
    The below test suites are passed for this patch:
    1. The rv64gcv fully regression tests.
    2. The x86 bootstrap tests.
    3. The x86 fully regression tests.
    
            PR middle-end/122031
    
    gcc/ChangeLog:
    
            * tree-ssa-math-opts.cc (build_and_insert_cast): Fix the typo
            of self assignment.
    
    Signed-off-by: Pan Li <pan2...@intel.com>

Diff:
---
 gcc/tree-ssa-math-opts.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/tree-ssa-math-opts.cc b/gcc/tree-ssa-math-opts.cc
index 80d10d26f678..a9903b691a49 100644
--- a/gcc/tree-ssa-math-opts.cc
+++ b/gcc/tree-ssa-math-opts.cc
@@ -1658,7 +1658,7 @@ build_and_insert_cast (gimple_stmt_iterator *gsi, 
location_t loc,
              /* Aka any sign extend from small to big size */
              if (!((val_prec > rhs_prec && !unsigned_val_p && !unsigned_rhs_p)
                  || (type_prec > val_prec && !unsigned_p && !unsigned_val_p)))
-               rhs = rhs;
+               rhs = cast_rhs;
            }
        }
     }