From 9f582e56baee0e7f5af20da0f395cd935bf5a962 Mon Sep 17 00:00:00 2001
From: Hamlin Li <mli@openjdk.org>
Date: Tue, 25 Mar 2025 09:29:40 +0000
Subject: [PATCH] 8320997: RISC-V: C2 ReverseV

Reviewed-by: fyang, luhenry
---
 src/hotspot/cpu/riscv/riscv_v.ad              | 27 +++++++++++++++++++
 .../vectorization/TestReverseBitsVector.java  |  4 ++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/hotspot/cpu/riscv/riscv_v.ad b/src/hotspot/cpu/riscv/riscv_v.ad
index 9892d2b9c03..cd9d2107b79 100644
--- a/src/hotspot/cpu/riscv/riscv_v.ad
+++ b/src/hotspot/cpu/riscv/riscv_v.ad
@@ -79,6 +79,7 @@ source %{
       case Op_PopCountVL:
       case Op_PopCountVI:
       case Op_ReverseBytesV:
+      case Op_ReverseV:
       case Op_RotateLeftV:
       case Op_RotateRightV:
         return UseZvbb;
@@ -4704,6 +4705,32 @@ instruct vround_d(vReg dst, vReg src, fRegD tmp, vRegMask_V0 v0) %{
   ins_pipe(pipe_slow);
 %}
 
+// -------------------------------- Reverse Bits Vector Operations ------------------------
+
+instruct vreverse_masked(vReg dst_src, vRegMask_V0 v0) %{
+  match(Set dst_src (ReverseV dst_src v0));
+  format %{ "vreverse_masked $dst_src, $dst_src, v0" %}
+  ins_encode %{
+    BasicType bt = Matcher::vector_element_basic_type(this);
+    uint vlen = Matcher::vector_length(this);
+    __ vsetvli_helper(bt, vlen);
+    __ vbrev_v(as_VectorRegister($dst_src$$reg), as_VectorRegister($dst_src$$reg), Assembler::v0_t);
+  %}
+  ins_pipe(pipe_slow);
+%}
+
+instruct vreverse(vReg dst, vReg src) %{
+  match(Set dst (ReverseV src));
+  format %{ "vreverse $dst, $src" %}
+  ins_encode %{
+    BasicType bt = Matcher::vector_element_basic_type(this);
+    uint vlen = Matcher::vector_length(this);
+    __ vsetvli_helper(bt, vlen);
+    __ vbrev_v(as_VectorRegister($dst$$reg), as_VectorRegister($src$$reg));
+  %}
+  ins_pipe(pipe_slow);
+%}
+
 // -------------------------------- Reverse Bytes Vector Operations ------------------------
 
 instruct vreverse_bytes_masked(vReg dst_src, vRegMask_V0 v0) %{
diff --git a/test/hotspot/jtreg/compiler/vectorization/TestReverseBitsVector.java b/test/hotspot/jtreg/compiler/vectorization/TestReverseBitsVector.java
index 1144186d8e5..c8c6586675a 100644
--- a/test/hotspot/jtreg/compiler/vectorization/TestReverseBitsVector.java
+++ b/test/hotspot/jtreg/compiler/vectorization/TestReverseBitsVector.java
@@ -25,7 +25,9 @@
  * @bug 8290034
  * @summary Auto-vectorization of Reverse bit operation.
  * @requires vm.compiler2.enabled
- * @requires (os.simpleArch == "x64" & vm.cpu.features ~= ".*avx2.*") | os.arch == "aarch64"
+ * @requires (os.simpleArch == "x64" & vm.cpu.features ~= ".*avx2.*") |
+ *           os.arch == "aarch64" |
+ *           (os.arch == "riscv64" & vm.cpu.features ~= ".*zbkb.*" & vm.cpu.features ~= ".*zvbb.*")
  * @library /test/lib /
  * @run driver compiler.vectorization.TestReverseBitsVector
  */