[RFC 2/5] target/riscv: Add support for Zfbfmin extension

[Weiwei Li]

Add trans_* and helper function for Zfbfmin instructions.

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
---
 target/riscv/fpu_helper.c                  | 12 +++++
 target/riscv/helper.h                      |  4 ++
 target/riscv/insn32.decode                 |  4 ++
 target/riscv/insn_trans/trans_rvbf16.c.inc | 53 ++++++++++++++++++++++
 target/riscv/insn_trans/trans_rvzfh.c.inc  | 12 ++---
 target/riscv/translate.c                   |  1 +
 6 files changed, 80 insertions(+), 6 deletions(-)
 create mode 100644 target/riscv/insn_trans/trans_rvbf16.c.inc

diff --git a/target/riscv/fpu_helper.c b/target/riscv/fpu_helper.c
index 449d236df6..013b52f9e3 100644
--- a/target/riscv/fpu_helper.c
+++ b/target/riscv/fpu_helper.c
@@ -593,3 +593,15 @@ uint64_t helper_fcvt_d_h(CPURISCVState *env, uint64_t rs1)
     float16 frs1 = check_nanbox_h(env, rs1);
     return float16_to_float64(frs1, true, &env->fp_status);
 }
+
+uint64_t helper_fcvt_bf16_s(CPURISCVState *env, uint64_t rs1)
+{
+    float32 frs1 = check_nanbox_s(env, rs1);
+    return nanbox_h(env, float32_to_bfloat16(frs1, &env->fp_status));
+}
+
+uint64_t helper_fcvt_s_bf16(CPURISCVState *env, uint64_t rs1)
+{
+    float16 frs1 = check_nanbox_h(env, rs1);
+    return nanbox_s(env, bfloat16_to_float32(frs1, &env->fp_status));
+}
diff --git a/target/riscv/helper.h b/target/riscv/helper.h
index 37b54e0991..7650168eb0 100644
--- a/target/riscv/helper.h
+++ b/target/riscv/helper.h
@@ -1142,3 +1142,7 @@ DEF_HELPER_FLAGS_1(aes64im, TCG_CALL_NO_RWG_SE, tl, tl)
 
 DEF_HELPER_FLAGS_3(sm4ed, TCG_CALL_NO_RWG_SE, tl, tl, tl, tl)
 DEF_HELPER_FLAGS_3(sm4ks, TCG_CALL_NO_RWG_SE, tl, tl, tl, tl)
+
+/* BF16 functions */
+DEF_HELPER_FLAGS_2(fcvt_bf16_s, TCG_CALL_NO_RWG, i64, env, i64)
+DEF_HELPER_FLAGS_2(fcvt_s_bf16, TCG_CALL_NO_RWG, i64, env, i64)
diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index 73d5d1b045..874a5cb974 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -908,3 +908,7 @@ sm4ks       .. 11010 ..... ..... 000 ..... 0110011 @k_aes
 # *** RV32 Zicond Standard Extension ***
 czero_eqz   0000111  ..... ..... 101 ..... 0110011 @r
 czero_nez   0000111  ..... ..... 111 ..... 0110011 @r
+
+# *** Zfbfmin Standard Extension ***
+fcvt_bf16_s       0100010  00100 ..... ... ..... 1010011 @r2_rm
+fcvt_s_bf16       0100000  00110 ..... ... ..... 1010011 @r2_rm
diff --git a/target/riscv/insn_trans/trans_rvbf16.c.inc 
b/target/riscv/insn_trans/trans_rvbf16.c.inc
new file mode 100644
index 0000000000..2a299075d8
--- /dev/null
+++ b/target/riscv/insn_trans/trans_rvbf16.c.inc
@@ -0,0 +1,53 @@
+/*
+ * RISC-V translation routines for the BF16 Standard Extensions.
+ *
+* Copyright (c) 2020-2023 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_ZFBFMIN(ctx) do { \
+    if (!ctx->cfg_ptr->ext_zfbfmin) { \
+        return false; \
+    } \
+} while (0)
+
+static bool trans_fcvt_bf16_s(DisasContext *ctx, arg_fcvt_bf16_s *a)
+{
+    REQUIRE_FPU;
+    REQUIRE_ZFBFMIN(ctx);
+
+    TCGv_i64 dest = dest_fpr(ctx, a->rd);
+    TCGv_i64 src1 = get_fpr_hs(ctx, a->rs1);
+
+    gen_set_rm(ctx, a->rm);
+    gen_helper_fcvt_bf16_s(dest, cpu_env, src1);
+    gen_set_fpr_hs(ctx, a->rd, dest);
+    mark_fs_dirty(ctx);
+    return true;
+}
+
+static bool trans_fcvt_s_bf16(DisasContext *ctx, arg_fcvt_s_bf16 *a)
+{
+    REQUIRE_FPU;
+    REQUIRE_ZFBFMIN(ctx);
+
+    TCGv_i64 dest = dest_fpr(ctx, a->rd);
+    TCGv_i64 src1 = get_fpr_hs(ctx, a->rs1);
+
+    gen_set_rm(ctx, a->rm);
+    gen_helper_fcvt_s_bf16(dest, cpu_env, src1);
+    gen_set_fpr_hs(ctx, a->rd, dest);
+    mark_fs_dirty(ctx);
+    return true;
+}
diff --git a/target/riscv/insn_trans/trans_rvzfh.c.inc 
b/target/riscv/insn_trans/trans_rvzfh.c.inc
index 74dde37ff7..8b1e2519bb 100644
--- a/target/riscv/insn_trans/trans_rvzfh.c.inc
+++ b/target/riscv/insn_trans/trans_rvzfh.c.inc
@@ -28,8 +28,8 @@
     }                                  \
 } while (0)
 
-#define REQUIRE_ZFHMIN(ctx) do {              \
-    if (!ctx->cfg_ptr->ext_zfhmin) {          \
+#define REQUIRE_ZFHMIN_OR_ZFBFMIN(ctx) do {   \
+    if (!ctx->cfg_ptr->ext_zfhmin && !ctx->cfg_ptr->ext_zfbfmin) { \
         return false;                         \
     }                                         \
 } while (0)
@@ -46,7 +46,7 @@ static bool trans_flh(DisasContext *ctx, arg_flh *a)
     TCGv t0;
 
     REQUIRE_FPU;
-    REQUIRE_ZFHMIN(ctx);
+    REQUIRE_ZFHMIN_OR_ZFBFMIN(ctx);
 
     decode_save_opc(ctx);
     t0 = get_gpr(ctx, a->rs1, EXT_NONE);
@@ -69,7 +69,7 @@ static bool trans_fsh(DisasContext *ctx, arg_fsh *a)
     TCGv t0;
 
     REQUIRE_FPU;
-    REQUIRE_ZFHMIN(ctx);
+    REQUIRE_ZFHMIN_OR_ZFBFMIN(ctx);
 
     decode_save_opc(ctx);
     t0 = get_gpr(ctx, a->rs1, EXT_NONE);
@@ -574,7 +574,7 @@ static bool trans_fcvt_h_wu(DisasContext *ctx, 
arg_fcvt_h_wu *a)
 static bool trans_fmv_x_h(DisasContext *ctx, arg_fmv_x_h *a)
 {
     REQUIRE_FPU;
-    REQUIRE_ZFHMIN(ctx);
+    REQUIRE_ZFHMIN_OR_ZFBFMIN(ctx);
 
     TCGv dest = dest_gpr(ctx, a->rd);
 
@@ -594,7 +594,7 @@ static bool trans_fmv_x_h(DisasContext *ctx, arg_fmv_x_h *a)
 static bool trans_fmv_h_x(DisasContext *ctx, arg_fmv_h_x *a)
 {
     REQUIRE_FPU;
-    REQUIRE_ZFHMIN(ctx);
+    REQUIRE_ZFHMIN_OR_ZFBFMIN(ctx);
 
     TCGv t0 = get_gpr(ctx, a->rs1, EXT_ZERO);
 
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index 0ee8ee147d..836229e87f 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -1085,6 +1085,7 @@ static uint32_t opcode_at(DisasContextBase *dcbase, 
target_ulong pc)
 #include "insn_trans/trans_rvk.c.inc"
 #include "insn_trans/trans_privileged.c.inc"
 #include "insn_trans/trans_svinval.c.inc"
+#include "insn_trans/trans_rvbf16.c.inc"
 #include "decode-xthead.c.inc"
 #include "insn_trans/trans_xthead.c.inc"
 #include "insn_trans/trans_xventanacondops.c.inc"
-- 
2.25.1