target/riscv: add vector configure instruction

vsetvl and vsetvli are two configure instructions for vl, vtype. TB flags
should update after configure instructions. The (ill, lmul, sew ) of vtype
and the bit of (VSTART == 0 && VL == VLMAX) will be placed within tb_flags.

Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200701152549.1218-5-zhiwei_liu@c-sky.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/target/riscv/vector_helper.c b/target/riscv/vector_helper.c
new file mode 100644
index 0000000000..40ed0d55e7
--- /dev/null
+++ b/target/riscv/vector_helper.c
@@ -0,0 +1,53 @@
+/*
+ * RISC-V Vector Extension Helpers for QEMU.
+ *
+ * Copyright (c) 2020 T-Head Semiconductor Co., Ltd. All rights reserved.
+ *
+ * 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/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/exec-all.h"
+#include "exec/helper-proto.h"
+#include <math.h>
+
+target_ulong HELPER(vsetvl)(CPURISCVState *env, target_ulong s1,
+                            target_ulong s2)
+{
+    int vlmax, vl;
+    RISCVCPU *cpu = env_archcpu(env);
+    uint16_t sew = 8 << FIELD_EX64(s2, VTYPE, VSEW);
+    uint8_t ediv = FIELD_EX64(s2, VTYPE, VEDIV);
+    bool vill = FIELD_EX64(s2, VTYPE, VILL);
+    target_ulong reserved = FIELD_EX64(s2, VTYPE, RESERVED);
+
+    if ((sew > cpu->cfg.elen) || vill || (ediv != 0) || (reserved != 0)) {
+        /* only set vill bit. */
+        env->vtype = FIELD_DP64(0, VTYPE, VILL, 1);
+        env->vl = 0;
+        env->vstart = 0;
+        return 0;
+    }
+
+    vlmax = vext_get_vlmax(cpu, s2);
+    if (s1 <= vlmax) {
+        vl = s1;
+    } else {
+        vl = vlmax;
+    }
+    env->vl = vl;
+    env->vtype = s2;
+    env->vstart = 0;
+    return vl;
+}