[gcc(refs/vendors/riscv/heads/gcc-13-with-riscv-opts)] RISC-V: Fix VL operand bug in VSETVL PASS[PR110264]

[Jeff Law]

https://gcc.gnu.org/g:2b227a449d5915b5af6c77fce08b430637c59e54

commit 2b227a449d5915b5af6c77fce08b430637c59e54
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Fri Jun 16 16:02:31 2023 +0800

    RISC-V: Fix VL operand bug in VSETVL PASS[PR110264]
    
    This patch fixes this issue happens on both GCC-13 and GCC-14.
    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110264
    
    The testcase is too big and I failed to reduce it so I didn't append
    test into this patch.
    
    This patch should not only land into GCC-14 but also should backport to GCC-13.
    
            PR target/110264
    
    gcc/ChangeLog:
    
            * config/riscv/riscv-vsetvl.cc (insert_vsetvl): Fix bug.

Diff:
---
 gcc/config/riscv/riscv-vsetvl.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index 7066dea3d14..971c3f90742 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -744,7 +744,10 @@ insert_vsetvl (enum emit_type emit_type, rtx_insn *rinsn,
   if (vlmax_avl_p (info.get_avl ()))
     {
       gcc_assert (has_vtype_op (rinsn) || vsetvl_insn_p (rinsn));
-      rtx vl_op = info.get_avl_reg_rtx ();
+      /* For user vsetvli a5, zero, we should use get_vl to get the VL
+	 operand "a5".  */
+      rtx vl_op
+	= vsetvl_insn_p (rinsn) ? get_vl (rinsn) : info.get_avl_reg_rtx ();
       gcc_assert (!vlmax_avl_p (vl_op));
       emit_vsetvl_insn (VSETVL_NORMAL, emit_type, info, vl_op, rinsn);
       return VSETVL_NORMAL;