target/riscv: add support for Zca extension

Modify the check for C extension to Zca (C implies Zca).

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>
Reviewed-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Message-Id: <20230307081403.61950-3-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/insn_trans/trans_rvi.c.inc

@@ -56,7 +56,7 @@ static bool trans_jalr(DisasContext *ctx, arg_jalr *a)
     tcg_gen_andi_tl(cpu_pc, cpu_pc, (target_ulong)-2);
 
     gen_set_pc(ctx, cpu_pc);
-    if (!has_ext(ctx, RVC)) {
+    if (!ctx->cfg_ptr->ext_zca) {
         TCGv t0 = tcg_temp_new();
 
         misaligned = gen_new_label();
@@ -169,7 +169,7 @@ static bool gen_branch(DisasContext *ctx, arg_b *a, TCGCond cond)
 
     gen_set_label(l); /* branch taken */
 
-    if (!has_ext(ctx, RVC) && ((ctx->base.pc_next + a->imm) & 0x3)) {
+    if (!ctx->cfg_ptr->ext_zca && ((ctx->base.pc_next + a->imm) & 0x3)) {
         /* misaligned */
         gen_exception_inst_addr_mis(ctx);
     } else {

target/riscv/translate.c

@@ -549,7 +549,7 @@ static void gen_jal(DisasContext *ctx, int rd, target_ulong imm)
 
     /* check misaligned: */
     next_pc = ctx->base.pc_next + imm;
-    if (!has_ext(ctx, RVC)) {
+    if (!ctx->cfg_ptr->ext_zca) {
         if ((next_pc & 0x3) != 0) {
             gen_exception_inst_addr_mis(ctx);
             return;
@@ -1122,7 +1122,11 @@ static void decode_opc(CPURISCVState *env, DisasContext *ctx, uint16_t opcode)
     if (insn_len(opcode) == 2) {
         ctx->opcode = opcode;
         ctx->pc_succ_insn = ctx->base.pc_next + 2;
-        if (has_ext(ctx, RVC) && decode_insn16(ctx, opcode)) {
+        /*
+         * The Zca extension is added as way to refer to instructions in the C
+         * extension that do not include the floating-point loads and stores
+         */
+        if (ctx->cfg_ptr->ext_zca && decode_insn16(ctx, opcode)) {
             return;
         }
     } else {