target/riscv: integer scalar move instruction

Backports 9fc08be626a96ae1ac0cffb22f30ae652c1c645a

qemu/target/riscv/insn32.decode

@@ -564,6 +564,7 @@ vmsof_m         010110 . ..... 00010 010 ..... 1010111 @r2_vm
 viota_m         010110 . ..... 10000 010 ..... 1010111 @r2_vm
 vid_v           010110 . 00000 10001 010 ..... 1010111 @r1_vm
 vext_x_v        001100 1 ..... ..... 010 ..... 1010111 @r
+vmv_s_x         001101 1 00000 ..... 110 ..... 1010111 @r2
 
 vsetvli         0 ........... ..... 111 ..... 1010111  @r2_zimm
 vsetvl          1000000 ..... ..... 111 ..... 1010111  @r

qemu/target/riscv/insn_trans/trans_rvv.inc.c

@@ -2699,3 +2699,66 @@ static bool trans_vext_x_v(DisasContext *s, arg_r *a)
     tcg_temp_free_i64(tcg_ctx, tmp);
     return true;
 }
+
+/* Integer Scalar Move Instruction */
+
+static void store_element(TCGContext *s, TCGv_i64 val, TCGv_ptr base,
+                          int ofs, int sew)
+{
+    switch (sew) {
+    case MO_8:
+        tcg_gen_st8_i64(s, val, base, ofs);
+        break;
+    case MO_16:
+        tcg_gen_st16_i64(s, val, base, ofs);
+        break;
+    case MO_32:
+        tcg_gen_st32_i64(s, val, base, ofs);
+        break;
+    case MO_64:
+        tcg_gen_st_i64(s, val, base, ofs);
+        break;
+    default:
+        g_assert_not_reached();
+        break;
+    }
+}
+
+/*
+ * Store vreg[idx] = val.
+ * The index must be in range of VLMAX.
+ */
+static void vec_element_storei(DisasContext *s, int vreg,
+                               int idx, TCGv_i64 val)
+{
+    TCGContext *tcg_ctx = s->uc->tcg_ctx;
+    store_element(tcg_ctx, val, tcg_ctx->cpu_env, endian_ofs(s, vreg, idx), s->sew);
+}
+
+/* vmv.s.x vd, rs1 # vd[0] = rs1 */
+static bool trans_vmv_s_x(DisasContext *s, arg_vmv_s_x *a)
+{
+    TCGContext *tcg_ctx = s->uc->tcg_ctx;
+
+    if (vext_check_isa_ill(s)) {
+        /* This instruction ignores LMUL and vector register groups */
+        int maxsz = s->vlen >> 3;
+        TCGv_i64 t1;
+        TCGLabel *over = gen_new_label(tcg_ctx);
+
+        tcg_gen_brcondi_tl(tcg_ctx, TCG_COND_EQ, tcg_ctx->cpu_vl_risc, 0, over);
+        tcg_gen_gvec_dup_imm(tcg_ctx, SEW64, vreg_ofs(s, a->rd), maxsz, maxsz, 0);
+        if (a->rs1 == 0) {
+            goto done;
+        }
+
+        t1 = tcg_temp_new_i64(tcg_ctx);
+        tcg_gen_extu_tl_i64(tcg_ctx, t1, tcg_ctx->cpu_gpr_risc[a->rs1]);
+        vec_element_storei(s, a->rd, 0, t1);
+        tcg_temp_free_i64(tcg_ctx, t1);
+    done:
+        gen_set_label(tcg_ctx, over);
+        return true;
+    }
+    return false;
+}

qemu/target/riscv/internals.h

@@ -34,4 +34,9 @@ target_ulong fclass_h_risc(uint64_t frs1);
 target_ulong fclass_s_risc(uint64_t frs1);
 target_ulong fclass_d_risc(uint64_t frs1);
 
+#define SEW8  0
+#define SEW16 1
+#define SEW32 2
+#define SEW64 3
+
 #endif