[PATCH] RISC-V: Add dynamic LMUL compile option

[Juzhe-Zhong]

We are going to support dynamic LMUL support.

gcc/ChangeLog:

        * config/riscv/riscv-opts.h (enum riscv_autovec_lmul_enum): Add dynamic 
enum.
        * config/riscv/riscv.opt: Add dynamic compile option.

---
 gcc/config/riscv/riscv-opts.h | 4 +++-
 gcc/config/riscv/riscv.opt    | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/gcc/config/riscv/riscv-opts.h b/gcc/config/riscv/riscv-opts.h
index 5ed69abd214..79e0f12e388 100644
--- a/gcc/config/riscv/riscv-opts.h
+++ b/gcc/config/riscv/riscv-opts.h
@@ -79,7 +79,9 @@ enum riscv_autovec_lmul_enum {
   RVV_M1 = 1,
   RVV_M2 = 2,
   RVV_M4 = 4,
-  RVV_M8 = 8
+  RVV_M8 = 8,
+  /* For dynamic LMUL, we compare COST start with LMUL8.  */
+  RVV_DYNAMIC = RVV_M8
 };
 
 enum riscv_multilib_select_kind {
diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt
index d2407c3c502..eca0dda4dd5 100644
--- a/gcc/config/riscv/riscv.opt
+++ b/gcc/config/riscv/riscv.opt
@@ -311,6 +311,9 @@ Enum(riscv_autovec_lmul) String(m4) Value(RVV_M4)
 EnumValue
 Enum(riscv_autovec_lmul) String(m8) Value(RVV_M8)
 
+EnumValue
+Enum(riscv_autovec_lmul) String(dynamic) Value(RVV_DYNAMIC)
+
 -param=riscv-autovec-lmul=
 Target RejectNegative Joined Enum(riscv_autovec_lmul) Var(riscv_autovec_lmul) 
Init(RVV_M1)
 -param=riscv-autovec-lmul=<string>     Set the RVV LMUL of auto-vectorization 
in the RISC-V port.
-- 
2.36.3