[RFC 3/8] target/riscv: add support for Zcb extension

[Weiwei Li]

Add encode and trans* functions support for Zcb instructions

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
---
 target/riscv/insn16.decode                |  22 ++++
 target/riscv/insn_trans/trans_rvzce.c.inc | 133 ++++++++++++++++++++++
 target/riscv/translate.c                  |   2 +
 3 files changed, 157 insertions(+)
 create mode 100644 target/riscv/insn_trans/trans_rvzce.c.inc

diff --git a/target/riscv/insn16.decode b/target/riscv/insn16.decode
index ccfe59f294..7ad673692e 100644
--- a/target/riscv/insn16.decode
+++ b/target/riscv/insn16.decode
@@ -43,6 +43,8 @@
 %imm_addi16sp  12:s1 3:2 5:1 2:1 6:1 !function=ex_shift_4
 %imm_lui       12:s1 2:5             !function=ex_shift_12
 
+%zcb_b_uimm  5:1 6:1
+%zcb_h_uimm  5:1                     !function=ex_shift_1
 
 # Argument sets imported from insn32.decode:
 &empty                  !extern
@@ -53,6 +55,7 @@
 &b         imm rs2 rs1  !extern
 &u         imm rd       !extern
 &shift     shamt rs1 rd !extern
+&r2        rd rs1       !extern
 
 
 # Formats 16:
@@ -89,6 +92,11 @@
 
 @c_andi         ... . .. ... ..... .. &i imm=%imm_ci rs1=%rs1_3 rd=%rs1_3
 
+@zcb_unary    ... ...  ... .. ... ..  &r2                  rs1=%rs1_3 rd=%rs1_3
+@zcb_binary   ... ...  ... .. ... ..  &r  rs2=%rs2_3       rs1=%rs1_3 rd=%rs1_3
+@zcb_b        ... . .. ... .. ... ..  &i  imm=%zcb_b_uimm  rs1=%rs1_3 rd=%rs2_3
+@zcb_h        ... . .. ... .. ... ..  &i  imm=%zcb_h_uimm  rs1=%rs1_3 rd=%rs2_3
+
 # *** RV32/64C Standard Extension (Quadrant 0) ***
 {
   # Opcode of all zeros is illegal; rd != 0, nzuimm == 0 is reserved.
@@ -180,3 +188,17 @@ sw                110 .  .....  ..... 10 @c_swsp
   sd              111 .  .....  ..... 10 @c_sdsp
   fsw             111 .  .....  ..... 10 @c_swsp
 }
+
+# *** RV64 and RV32 Zcb Extension ***
+c_zext_b          100 111  ... 11 000 01 @zcb_unary
+c_sext_b          100 111  ... 11 001 01 @zcb_unary
+c_zext_h          100 111  ... 11 010 01 @zcb_unary
+c_sext_h          100 111  ... 11 011 01 @zcb_unary
+c_zext_w          100 111  ... 11 100 01 @zcb_unary
+c_not             100 111  ... 11 101 01 @zcb_unary
+c_mul             100 111  ... 10 ... 01 @zcb_binary
+c_lbu             100 000  ... .. ... 00 @zcb_b
+c_lhu             100 001  ... 0. ... 00 @zcb_h
+c_lh              100 001  ... 1. ... 00 @zcb_h
+c_sb              100 010  ... .. ... 00 @zcb_b
+c_sh              100 011  ... 0. ... 00 @zcb_h
diff --git a/target/riscv/insn_trans/trans_rvzce.c.inc 
b/target/riscv/insn_trans/trans_rvzce.c.inc
new file mode 100644
index 0000000000..0947190f2d
--- /dev/null
+++ b/target/riscv/insn_trans/trans_rvzce.c.inc
@@ -0,0 +1,133 @@
+/*
+ * RISC-V translation routines for the Zcb Standard Extension.
+ *
+ * Copyright (c) 2021-2022 PLCT Lab
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2 or later, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define REQUIRE_ZCB(ctx) do {   \
+    if (!ctx->cfg_ptr->ext_zcb) \
+        return false;           \
+} while (0)
+
+static bool trans_c_zext_b(DisasContext *ctx, arg_c_zext_b *a)
+{
+    REQUIRE_ZCB(ctx);
+    return gen_unary(ctx, a, EXT_NONE, tcg_gen_ext8u_tl);
+}
+
+static bool trans_c_zext_h(DisasContext *ctx, arg_c_zext_h *a)
+{
+    REQUIRE_ZCB(ctx);
+    REQUIRE_ZBB(ctx);
+    return gen_unary(ctx, a, EXT_NONE, tcg_gen_ext16u_tl);
+}
+
+static bool trans_c_sext_b(DisasContext *ctx, arg_c_sext_b *a)
+{
+    REQUIRE_ZCB(ctx);
+    REQUIRE_ZBB(ctx);
+    return gen_unary(ctx, a, EXT_NONE, tcg_gen_ext8s_tl);
+}
+
+static bool trans_c_sext_h(DisasContext *ctx, arg_c_sext_h *a)
+{
+    REQUIRE_ZCB(ctx);
+    REQUIRE_ZBB(ctx);
+    return gen_unary(ctx, a, EXT_NONE, tcg_gen_ext16s_tl);
+}
+
+static bool trans_c_zext_w(DisasContext *ctx, arg_c_zext_w *a)
+{
+    REQUIRE_64BIT(ctx);
+    REQUIRE_ZCB(ctx);
+    REQUIRE_ZBA(ctx);
+    return gen_unary(ctx, a, EXT_NONE, tcg_gen_ext32u_tl);
+}
+
+static bool trans_c_not(DisasContext *ctx, arg_c_not *a)
+{
+    REQUIRE_ZCB(ctx);
+    return gen_unary(ctx, a, EXT_NONE, tcg_gen_not_tl);
+}
+
+static bool trans_c_mul(DisasContext *ctx, arg_c_mul *a)
+{
+    REQUIRE_ZCB(ctx);
+    REQUIRE_M_OR_ZMMUL(ctx);
+    return gen_arith(ctx, a, EXT_NONE, tcg_gen_mul_tl, NULL);
+}
+
+static bool gen_zce_load(DisasContext *ctx, arg_i *a, MemOp memop)
+{
+    TCGv dest = dest_gpr(ctx, a->rd);
+    TCGv src1 = get_gpr(ctx, a->rs1, EXT_NONE);
+    TCGv t0 = tcg_temp_new();
+
+    tcg_gen_addi_tl(t0, src1, a->imm);
+
+    tcg_gen_qemu_ld_tl(dest, t0, ctx->mem_idx, memop);
+    gen_set_gpr(ctx, a->rd, dest);
+
+    tcg_temp_free(t0);
+    return true;
+}
+
+static bool trans_c_lbu(DisasContext *ctx, arg_c_lbu *a)
+{
+    REQUIRE_ZCB(ctx);
+    MemOp memop = MO_UB;
+    return gen_zce_load(ctx, a, memop);
+}
+
+static bool trans_c_lhu(DisasContext *ctx, arg_c_lhu *a)
+{
+    REQUIRE_ZCB(ctx);
+    MemOp memop = MO_UW;
+    return gen_zce_load(ctx, a, memop);
+}
+
+static bool trans_c_lh(DisasContext *ctx, arg_c_lh *a)
+{
+    REQUIRE_ZCB(ctx);
+    MemOp memop = MO_SW;
+    return gen_zce_load(ctx, a, memop);
+}
+
+static bool gen_zce_store(DisasContext *ctx, arg_i *a, MemOp memop)
+{
+    TCGv src1 = get_gpr(ctx, a->rs1, EXT_NONE);
+    TCGv src2 = get_gpr(ctx, a->rd, EXT_NONE);
+    TCGv t0 = tcg_temp_new();
+
+    tcg_gen_addi_tl(t0, src1, a->imm);
+    tcg_gen_qemu_st_tl(src2, t0, ctx->mem_idx, memop);
+
+    tcg_temp_free(t0);
+    return true;
+}
+
+static bool trans_c_sb(DisasContext *ctx, arg_c_sb *a)
+{
+    REQUIRE_ZCB(ctx);
+    MemOp memop = MO_UB;
+    return gen_zce_store(ctx, a, memop);
+}
+
+static bool trans_c_sh(DisasContext *ctx, arg_c_sh *a)
+{
+    REQUIRE_ZCB(ctx);
+    MemOp memop = MO_UW;
+    return gen_zce_store(ctx, a, memop);
+}
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index a257f0123e..c0b8aa340b 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -1037,6 +1037,8 @@ static uint32_t opcode_at(DisasContextBase *dcbase, 
target_ulong pc)
 
 /* Include the auto-generated decoder for 16 bit insn */
 #include "decode-insn16.c.inc"
+#include "insn_trans/trans_rvzce.c.inc"
+
 /* Include decoders for factored-out extensions */
 #include "decode-XVentanaCondOps.c.inc"
 
-- 
2.25.1