On 11/14/25 6:01 AM, [email protected] wrote:
From: Frank Chang <[email protected]> MISA.C is set if the following extensions are selected: * Zca and not F. * Zca, Zcf and F (but not D) is specified (RV32 only). * Zca, Zcf and Zcd if D is specified (RV32 only). * Zca, Zcd if D is specified (RV64 only). Therefore, we need to set MISA.C according to the rules for Zc* extensions. Signed-off-by: Frank Chang <[email protected]> Reviewed-by: Max Chou <[email protected]> ---
Reviewed-by: Daniel Henrique Barboza <[email protected]>
target/riscv/tcg/tcg-cpu.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/target/riscv/tcg/tcg-cpu.c b/target/riscv/tcg/tcg-cpu.c index 440626ddfad..da09a2417cc 100644 --- a/target/riscv/tcg/tcg-cpu.c +++ b/target/riscv/tcg/tcg-cpu.c @@ -1150,6 +1150,36 @@ static void riscv_cpu_enable_implied_rules(RISCVCPU *cpu) } }+/*+ * MISA.C is set if the following extensions are selected: + * - Zca and not F. + * - Zca, Zcf and F (but not D) is specified on RV32. + * - Zca, Zcf and Zcd if D is specified on RV32. + * - Zca, Zcd if D is specified on RV64. + */ +static void riscv_cpu_update_misa_c(RISCVCPU *cpu) +{ + CPURISCVState *env = &cpu->env; + + if (cpu->cfg.ext_zca && !riscv_has_ext(env, RVF)) { + riscv_cpu_set_misa_ext(env, env->misa_ext | RVC); + return; + } + + if (riscv_cpu_mxl(env) == MXL_RV32 && + cpu->cfg.ext_zca && cpu->cfg.ext_zcf && + riscv_has_ext(env, RVD) ? cpu->cfg.ext_zcd : riscv_has_ext(env, RVF)) { + riscv_cpu_set_misa_ext(env, env->misa_ext | RVC); + return; + } + + if (riscv_cpu_mxl(env) == MXL_RV64 && + cpu->cfg.ext_zca && cpu->cfg.ext_zcd) { + riscv_cpu_set_misa_ext(env, env->misa_ext | RVC); + return; + } +} + void riscv_tcg_cpu_finalize_features(RISCVCPU *cpu, Error **errp) { CPURISCVState *env = &cpu->env; @@ -1157,6 +1187,7 @@ void riscv_tcg_cpu_finalize_features(RISCVCPU *cpu, Error **errp)riscv_cpu_init_implied_exts_rules();riscv_cpu_enable_implied_rules(cpu); + riscv_cpu_update_misa_c(cpu);riscv_cpu_validate_misa_priv(env, &local_err);if (local_err != NULL) {
