[PATCH] RISC-V: skip vector tests if target not supporting v extension

[Jerry Zhang Jian]

The original method tried to overwrite the march option when the target
doesn't support v exctension, which caused unexpected compile and
runtime test failures

This patch change the way to handle targets that don't support v
extension by simply skip the test cases that requires v extension

The test cases under g[cc|++].dg/vect/vect.exp will be skipped on rv64gc after 
this patch

gcc/testsuite/ChangeLog:

        * lib/target-supports.exp: skip vector tests if target not supporting v 
extension

Signed-off-by: Jerry Zhang Jian <jerry.zhangj...@sifive.com>
---
 gcc/testsuite/lib/target-supports.exp | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/gcc/testsuite/lib/target-supports.exp 
b/gcc/testsuite/lib/target-supports.exp
index f001c28072f..71d7e569a7d 100644
--- a/gcc/testsuite/lib/target-supports.exp
+++ b/gcc/testsuite/lib/target-supports.exp
@@ -11807,10 +11807,7 @@ proc check_vect_support_and_set_flags { } {
                lappend DEFAULT_VECTCFLAGS "-mno-vector-strict-align"
            }
        } else {
-           foreach item [add_options_for_riscv_v ""] {
-               lappend DEFAULT_VECTCFLAGS $item
-           }
-           set dg-do-what-default compile
+           return 0
        }
     } elseif [istarget loongarch*-*-*] {
       # Set the default vectorization option to "-mlsx" due to the problem
-- 
2.45.2