[PATCH] RISC-V: Improve vector_insn_info::dump for LMUL and policy

[Kito Cheng <kito.cheng@sifive.com>]

Convert vlmul and policy to human readable string, some example below:

Before:
[VALID,Demand field={1(VL),0(DEMAND_NONZERO_AVL),1(SEW),0(DEMAND_GE_SEW),1(LMUL),0(RATIO),0(TAIL_POLICY),0(MASK_POLICY)}
AVL=(reg:DI 0 zero)
SEW=16,VLMUL=3,RATIO=2,TAIL_POLICY=1,MASK_POLICY=1]
             ^                     ^             ^

After:
[VALID,Demand field={1(VL),0(DEMAND_NONZERO_AVL),1(SEW),0(DEMAND_GE_SEW),1(LMUL),0(RATIO),0(TAIL_POLICY),0(MASK_POLICY)}
AVL=(reg:DI 0 zero)
SEW=16,VLMUL=m8,RATIO=2,TAIL_POLICY=agnostic,MASK_POLICY=agnostic]
             ^^                     ^^^^^^^^             ^^^^^^^^

gcc/ChangeLog:

	* config/riscv/riscv-vsetvl.cc (vlmul_to_str): New.
	(policy_to_str): New.
	(vector_insn_info::dump): Use vlmul_to_str and policy_to_str.
---
 gcc/config/riscv/riscv-vsetvl.cc | 39 +++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/gcc/config/riscv/riscv-vsetvl.cc b/gcc/config/riscv/riscv-vsetvl.cc
index f1c47e8f9be3..5c4b349dd9db 100644
--- a/gcc/config/riscv/riscv-vsetvl.cc
+++ b/gcc/config/riscv/riscv-vsetvl.cc
@@ -2241,6 +2241,39 @@ vector_insn_info::update_fault_first_load_avl (insn_info *insn)
   return false;
 }
 
+static const char *
+vlmul_to_str (vlmul_type vlmul)
+{
+  switch (vlmul)
+    {
+    case LMUL_1:
+      return "m1";
+    case LMUL_2:
+      return "m2";
+    case LMUL_4:
+      return "m4";
+    case LMUL_8:
+      return "m8";
+    case LMUL_RESERVED:
+      return "INVALID LMUL";
+    case LMUL_F8:
+      return "mf8";
+    case LMUL_F4:
+      return "mf4";
+    case LMUL_F2:
+      return "mf2";
+
+    default:
+      gcc_unreachable ();
+    }
+}
+
+static const char *
+policy_to_str (bool agnostic_p)
+{
+  return agnostic_p ? "agnostic" : "undisturbed";
+}
+
 void
 vector_insn_info::dump (FILE *file) const
 {
@@ -2272,10 +2305,10 @@ vector_insn_info::dump (FILE *file) const
   fprintf (file, "AVL=");
   print_rtl_single (file, get_avl ());
   fprintf (file, "SEW=%d,", get_sew ());
-  fprintf (file, "VLMUL=%d,", get_vlmul ());
+  fprintf (file, "VLMUL=%s,", vlmul_to_str (get_vlmul ()));
   fprintf (file, "RATIO=%d,", get_ratio ());
-  fprintf (file, "TAIL_POLICY=%d,", get_ta ());
-  fprintf (file, "MASK_POLICY=%d", get_ma ());
+  fprintf (file, "TAIL_POLICY=%s,", policy_to_str (get_ta ()));
+  fprintf (file, "MASK_POLICY=%s", policy_to_str (get_ma ()));
   fprintf (file, "]\n");
 
   if (valid_p ())
-- 
2.39.2