target/riscv: rvk: add support for zbkx extension

 - add xperm4 and xperm8 instructions

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220423023510.30794-5-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/bitmanip_helper.c

@@ -102,3 +102,30 @@ target_ulong HELPER(zip)(target_ulong rs1)
     x = do_shuf_stage(x, shuf_masks[0], shuf_masks[0] >> 1, 1);
     return x;
 }
+
+static inline target_ulong do_xperm(target_ulong rs1, target_ulong rs2,
+                                    uint32_t sz_log2)
+{
+    target_ulong r = 0;
+    target_ulong sz = 1LL << sz_log2;
+    target_ulong mask = (1LL << sz) - 1;
+    target_ulong pos;
+
+    for (int i = 0; i < TARGET_LONG_BITS; i += sz) {
+        pos = ((rs2 >> i) & mask) << sz_log2;
+        if (pos < sizeof(target_ulong) * 8) {
+            r |= ((rs1 >> pos) & mask) << i;
+        }
+    }
+    return r;
+}
+
+target_ulong HELPER(xperm4)(target_ulong rs1, target_ulong rs2)
+{
+    return do_xperm(rs1, rs2, 2);
+}
+
+target_ulong HELPER(xperm8)(target_ulong rs1, target_ulong rs2)
+{
+    return do_xperm(rs1, rs2, 3);
+}

target/riscv/helper.h

@@ -69,6 +69,8 @@ DEF_HELPER_FLAGS_2(clmulr, TCG_CALL_NO_RWG_SE, tl, tl, tl)
 DEF_HELPER_FLAGS_1(brev8, TCG_CALL_NO_RWG_SE, tl, tl)
 DEF_HELPER_FLAGS_1(unzip, TCG_CALL_NO_RWG_SE, tl, tl)
 DEF_HELPER_FLAGS_1(zip, TCG_CALL_NO_RWG_SE, tl, tl)
+DEF_HELPER_FLAGS_2(xperm4, TCG_CALL_NO_RWG_SE, tl, tl, tl)
+DEF_HELPER_FLAGS_2(xperm8, TCG_CALL_NO_RWG_SE, tl, tl, tl)
 
 /* Floating Point - Half Precision */
 DEF_HELPER_FLAGS_3(fadd_h, TCG_CALL_NO_RWG, i64, env, i64, i64)

target/riscv/insn32.decode

@@ -776,6 +776,10 @@ clmulh     0000101 .......... 011 ..... 0110011 @r
 # *** RV32 extra Zbc Standard Extension ***
 clmulr     0000101 .......... 010 ..... 0110011 @r
 
+# *** RV32 Zbkx Standard Extension ***
+xperm4     0010100 .......... 010 ..... 0110011 @r
+xperm8     0010100 .......... 100 ..... 0110011 @r
+
 # *** RV32 Zbs Standard Extension ***
 bclr       0100100 .......... 001 ..... 0110011 @r
 bclri      01001. ........... 001 ..... 0010011 @sh

target/riscv/insn_trans/trans_rvb.c.inc

@@ -48,6 +48,12 @@
     }                                            \
 } while (0)
 
+#define REQUIRE_ZBKX(ctx) do {                   \
+    if (!ctx->cfg_ptr->ext_zbkx) {               \
+        return false;                            \
+    }                                            \
+} while (0)
+
 static void gen_clz(TCGv ret, TCGv arg1)
 {
     tcg_gen_clzi_tl(ret, arg1, TARGET_LONG_BITS);
@@ -574,3 +580,15 @@ static bool trans_zip(DisasContext *ctx, arg_zip *a)
     REQUIRE_ZBKB(ctx);
     return gen_unary(ctx, a, EXT_NONE, gen_helper_zip);
 }
+
+static bool trans_xperm4(DisasContext *ctx, arg_xperm4 *a)
+{
+    REQUIRE_ZBKX(ctx);
+    return gen_arith(ctx, a, EXT_NONE, gen_helper_xperm4, NULL);
+}
+
+static bool trans_xperm8(DisasContext *ctx, arg_xperm8 *a)
+{
+    REQUIRE_ZBKX(ctx);
+    return gen_arith(ctx, a, EXT_NONE, gen_helper_xperm8, NULL);
+}