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 --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index 7066dea3d14430517750017513ec0f6bc675919a..971c3f907424cc0389888ac17851983b3bdcc5f8 100644 (file)
--- 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;