On 2023/4/15 00:02, Mayuresh Chitale wrote:
When misa.F is clear, TB_FLAGS.MSTATUS_HS_FS field is unused and can
be used to save the current state of smstateen0.FCSR check which is
needed by the floating point translation routines.
Signed-off-by: Mayuresh Chitale <mchit...@ventanamicro.com>
---
target/riscv/cpu_helper.c | 12 ++++++++++++
target/riscv/translate.c | 7 +++++++
2 files changed, 19 insertions(+)
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 433ea529b0..fd1731cc39 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -105,6 +105,18 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong
*pc,
flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_VS,
get_field(env->mstatus_hs, MSTATUS_VS));
}
+ /*
+ * If misa.F is 0 then the MSTATUS_HS_FS field of the tb->flags
+ * can be used to pass the current state of the smstateen.FCSR bit
+ * which must be checked for in the floating point translation routines
+ */
+ if (!riscv_has_ext(env, RVF)) {
+ if (smstateen_acc_ok(env, 0, SMSTATEEN0_FCSR) == RISCV_EXCP_NONE) {
+ flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_FS, 1);
+ } else {
+ flags = FIELD_DP32(flags, TB_FLAGS, MSTATUS_HS_FS, 0);
+ }
+ }
if (cpu->cfg.debug && !icount_enabled()) {
flags = FIELD_DP32(flags, TB_FLAGS, ITRIGGER, env->itrigger_enabled);
}
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index d0094922b6..e29bbb8b70 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -79,6 +79,7 @@ typedef struct DisasContext {
int frm;
RISCVMXL ol;
bool virt_inst_excp;
+ bool smstateen_fcsr_ok;
bool virt_enabled;
const RISCVCPUConfig *cfg_ptr;
bool hlsx;
@@ -1202,6 +1203,12 @@ static void riscv_tr_init_disas_context(DisasContextBase
*dcbase, CPUState *cs)
ctx->itrigger = FIELD_EX32(tb_flags, TB_FLAGS, ITRIGGER);
ctx->zero = tcg_constant_tl(0);
ctx->virt_inst_excp = false;
+ if (has_ext(ctx, RVF)) {
+ ctx->smstateen_fcsr_ok = 1;
+ } else {
+ ctx->smstateen_fcsr_ok = FIELD_EX32(tb_flags, TB_FLAGS,
+ MSTATUS_HS_FS);
By the way, it may introduce new question when MSTATUS_FS and
MSTATUS_HS_FS is merged to save bits in tb_flag
by Richerd's patchset: 20230412114333.118895-5-richard.hender...@linaro.org
such as: the check "s->mstatus_fs == 0" in require_rvf() will be false
if smstateen_fcsr_ok is true.
However, this should be true in this case to indicate F is diabled.
So we may need to set ctx->mstatus_fs = 0 here once merged with
Richerd's patchset.
Regards,
Weiwei Li
+ }
}
static void riscv_tr_tb_start(DisasContextBase *db, CPUState *cpu)
