From d13e53346f3cd50bf7a4241ba86d2e21d9081bbe Mon Sep 17 00:00:00 2001
From: Hamlin Li <mli@openjdk.org>
Date: Fri, 26 Apr 2024 14:09:29 +0000
Subject: [PATCH] 8321014: RISC-V: C2 VectorLoadShuffle

Reviewed-by: luhenry, fyang
---
 src/hotspot/cpu/riscv/riscv_v.ad | 44 ++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/src/hotspot/cpu/riscv/riscv_v.ad b/src/hotspot/cpu/riscv/riscv_v.ad
index 3069336ac11..7869d6156e5 100644
--- a/src/hotspot/cpu/riscv/riscv_v.ad
+++ b/src/hotspot/cpu/riscv/riscv_v.ad
@@ -82,6 +82,15 @@ source %{
       case Op_VectorCastHF2F:
       case Op_VectorCastF2HF:
         return UseZvfh;
+      case Op_VectorLoadShuffle:
+      case Op_VectorRearrange:
+        // vlen >= 4 is required, because min vector size for byte is 4 on riscv,
+        // VectorLoadShuffle is from byte to X, so it requires vlen >= 4.
+        // VectorRearrange depends on VectorLoadShuffle, so it also requires vlen >= 4.
+        if (vlen < 4) {
+          return false;
+        }
+        break;
       default:
         break;
     }
@@ -3561,6 +3570,41 @@ instruct vmask_reinterpret_diff_esize(vRegMask dst, vRegMask_V0 src, vReg tmp) %
   ins_pipe(pipe_slow);
 %}
 
+// ------------------------------ Vector shuffle -------------------------------
+
+instruct loadshuffleB(vReg dst) %{
+  predicate(Matcher::vector_element_basic_type(n) == T_BYTE);
+  match(Set dst (VectorLoadShuffle dst));
+  format %{ "loadshuffleB $dst, $dst" %}
+  ins_encode %{
+    // For T_BYTE, no need to do anything
+  %}
+  ins_pipe(pipe_class_empty);
+%}
+
+instruct loadshuffleX(vReg dst, vReg src) %{
+  predicate(Matcher::vector_element_basic_type(n) == T_DOUBLE ||
+            Matcher::vector_element_basic_type(n) == T_LONG ||
+            Matcher::vector_element_basic_type(n) == T_FLOAT ||
+            Matcher::vector_element_basic_type(n) == T_INT ||
+            Matcher::vector_element_basic_type(n) == T_SHORT);
+  match(Set dst (VectorLoadShuffle src));
+  effect(TEMP_DEF dst);
+  format %{ "loadshuffleX $dst, $src" %}
+  ins_encode %{
+    BasicType bt = Matcher::vector_element_basic_type(this);
+    __ vsetvli_helper(bt, Matcher::vector_length(this));
+    if (bt == T_SHORT) {
+      __ vzext_vf2(as_VectorRegister($dst$$reg), as_VectorRegister($src$$reg));
+    } else if (bt == T_FLOAT || bt == T_INT) {
+      __ vzext_vf4(as_VectorRegister($dst$$reg), as_VectorRegister($src$$reg));
+    } else { // bt == T_DOUBLE || bt == T_LONG
+      __ vzext_vf8(as_VectorRegister($dst$$reg), as_VectorRegister($src$$reg));
+    }
+  %}
+  ins_pipe(pipe_slow);
+%}
+
 // ------------------------------ Vector rearrange -----------------------------
 
 instruct rearrange(vReg dst, vReg src, vReg shuffle) %{