From 642084629a9a793a055cba8a950fdb61b7450093 Mon Sep 17 00:00:00 2001
From: Hamlin Li <mli@openjdk.org>
Date: Thu, 20 Jun 2024 10:10:54 +0000
Subject: [PATCH] 8334396: RISC-V: verify perf of ReverseBytesI/L

Reviewed-by: fyang, rehn
---
 src/hotspot/cpu/riscv/riscv.ad   | 31 +++----------------------------
 src/hotspot/cpu/riscv/riscv_b.ad |  4 ++--
 2 files changed, 5 insertions(+), 30 deletions(-)

diff --git a/src/hotspot/cpu/riscv/riscv.ad b/src/hotspot/cpu/riscv/riscv.ad
index 54053148758..2368a280bf2 100644
--- a/src/hotspot/cpu/riscv/riscv.ad
+++ b/src/hotspot/cpu/riscv/riscv.ad
@@ -1914,6 +1914,8 @@ bool Matcher::match_rule_supported(int opcode) {
     case Op_PopCountL:
       return UsePopCountInstruction;
 
+    case Op_ReverseBytesI:
+    case Op_ReverseBytesL:
     case Op_RotateRight:
     case Op_RotateLeft:
     case Op_CountLeadingZerosI:
@@ -1921,6 +1923,7 @@ bool Matcher::match_rule_supported(int opcode) {
     case Op_CountTrailingZerosI:
     case Op_CountTrailingZerosL:
       return UseZbb;
+
     case Op_FmaF:
     case Op_FmaD:
     case Op_FmaVF:
@@ -7856,34 +7859,6 @@ instruct xorL_reg_imm(iRegLNoSp dst, iRegL src1, immLAdd src2) %{
 // ============================================================================
 // BSWAP Instructions
 
-instruct bytes_reverse_int(iRegINoSp dst, iRegIorL2I src, rFlagsReg cr) %{
-  match(Set dst (ReverseBytesI src));
-  effect(KILL cr);
-
-  ins_cost(ALU_COST * 13);
-  format %{ "revb_w_w  $dst, $src\t#@bytes_reverse_int" %}
-
-  ins_encode %{
-    __ revb_w_w(as_Register($dst$$reg), as_Register($src$$reg));
-  %}
-
-  ins_pipe(pipe_class_default);
-%}
-
-instruct bytes_reverse_long(iRegLNoSp dst, iRegL src, rFlagsReg cr) %{
-  match(Set dst (ReverseBytesL src));
-  effect(KILL cr);
-
-  ins_cost(ALU_COST * 29);
-  format %{ "revb  $dst, $src\t#@bytes_reverse_long" %}
-
-  ins_encode %{
-    __ revb(as_Register($dst$$reg), as_Register($src$$reg));
-  %}
-
-  ins_pipe(pipe_class_default);
-%}
-
 instruct bytes_reverse_unsigned_short(iRegINoSp dst, iRegIorL2I src) %{
   match(Set dst (ReverseBytesUS src));
 
diff --git a/src/hotspot/cpu/riscv/riscv_b.ad b/src/hotspot/cpu/riscv/riscv_b.ad
index b8960e5e9fd..9e78159d24f 100644
--- a/src/hotspot/cpu/riscv/riscv_b.ad
+++ b/src/hotspot/cpu/riscv/riscv_b.ad
@@ -178,13 +178,13 @@ instruct convI2UL_reg_reg_b(iRegLNoSp dst, iRegIorL2I src, immL_32bits mask) %{
 
 // BSWAP instructions
 instruct bytes_reverse_int_b(iRegINoSp dst, iRegIorL2I src) %{
-  predicate(UseZbb);
   match(Set dst (ReverseBytesI src));
 
   ins_cost(ALU_COST * 2);
   format %{ "revb_w_w  $dst, $src\t#@bytes_reverse_int_b" %}
 
   ins_encode %{
+    assert(UseZbb, "must be");
     __ revb_w_w(as_Register($dst$$reg), as_Register($src$$reg));
   %}
 
@@ -192,13 +192,13 @@ instruct bytes_reverse_int_b(iRegINoSp dst, iRegIorL2I src) %{
 %}
 
 instruct bytes_reverse_long_b(iRegLNoSp dst, iRegL src) %{
-  predicate(UseZbb);
   match(Set dst (ReverseBytesL src));
 
   ins_cost(ALU_COST);
   format %{ "rev8  $dst, $src\t#@bytes_reverse_long_b" %}
 
   ins_encode %{
+    assert(UseZbb, "must be");
     __ rev8(as_Register($dst$$reg), as_Register($src$$reg));
   %}