target/riscv: add support for Zcd extension

Separate c_fld/c_fsd from fld/fsd to add additional check for
c.fld{sp}/c.fsd{sp} which is useful for zcmp/zcmt to reuse
their encodings.

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>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230307081403.61950-5-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/insn16.decode

@@ -97,12 +97,12 @@
 }
 {
   lq              001  ... ... .. ... 00 @cl_q
-  fld             001  ... ... .. ... 00 @cl_d
+  c_fld           001  ... ... .. ... 00 @cl_d
 }
 lw                010  ... ... .. ... 00 @cl_w
 {
   sq              101  ... ... .. ... 00 @cs_q
-  fsd             101  ... ... .. ... 00 @cs_d
+  c_fsd           101  ... ... .. ... 00 @cs_d
 }
 sw                110  ... ... .. ... 00 @cs_w
 
@@ -148,7 +148,7 @@ addw              100 1 11 ... 01 ... 01 @cs_2
 slli              000 .  .....  ..... 10 @c_shift2
 {
   lq              001  ... ... .. ... 10 @c_lqsp
-  fld             001 .  .....  ..... 10 @c_ldsp
+  c_fld           001 .  .....  ..... 10 @c_ldsp
 }
 {
   illegal         010 -  00000  ----- 10 # c.lwsp, RES rd=0
@@ -166,7 +166,7 @@ slli              000 .  .....  ..... 10 @c_shift2
 }
 {
   sq              101  ... ... .. ... 10 @c_sqsp
-  fsd             101   ......  ..... 10 @c_sdsp
+  c_fsd           101   ......  ..... 10 @c_sdsp
 }
 sw                110 .  .....  ..... 10 @c_swsp
 

target/riscv/insn_trans/trans_rvd.c.inc

@@ -31,6 +31,12 @@
     } \
 } while (0)
 
+#define REQUIRE_ZCD(ctx) do { \
+    if (!ctx->cfg_ptr->ext_zcd) {  \
+        return false;     \
+    } \
+} while (0)
+
 static bool trans_fld(DisasContext *ctx, arg_fld *a)
 {
     TCGv addr;
@@ -59,6 +65,18 @@ static bool trans_fsd(DisasContext *ctx, arg_fsd *a)
     return true;
 }
 
+static bool trans_c_fld(DisasContext *ctx, arg_fld *a)
+{
+    REQUIRE_ZCD(ctx);
+    return trans_fld(ctx, a);
+}
+
+static bool trans_c_fsd(DisasContext *ctx, arg_fsd *a)
+{
+    REQUIRE_ZCD(ctx);
+    return trans_fsd(ctx, a);
+}
+
 static bool trans_fmadd_d(DisasContext *ctx, arg_fmadd_d *a)
 {
     REQUIRE_FPU;