target/openrisc: Exit the TB after l.mtspr

A store to SR changes interrupt state, which should return
to the main loop to recognize that state.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/target/openrisc/translate.c b/target/openrisc/translate.c
index db14998..59605aa 100644
--- a/target/openrisc/translate.c
+++ b/target/openrisc/translate.c
@@ -877,7 +877,22 @@ static bool trans_l_mtspr(DisasContext *dc, arg_l_mtspr *a, uint32_t insn)
     if (is_user(dc)) {
         gen_illegal_exception(dc);
     } else {
-        TCGv_i32 ti = tcg_const_i32(a->k);
+        TCGv_i32 ti;
+
+        /* For SR, we will need to exit the TB to recognize the new
+         * exception state.  For NPC, in theory this counts as a branch
+         * (although the SPR only exists for use by an ICE).  Save all
+         * of the cpu state first, allowing it to be overwritten.
+         */
+        if (dc->delayed_branch) {
+            tcg_gen_mov_tl(cpu_pc, jmp_pc);
+            tcg_gen_discard_tl(jmp_pc);
+        } else {
+            tcg_gen_movi_tl(cpu_pc, dc->base.pc_next + 4);
+        }
+        dc->base.is_jmp = DISAS_EXIT;
+
+        ti = tcg_const_i32(a->k);
         gen_helper_mtspr(cpu_env, cpu_R[a->a], cpu_R[a->b], ti);
         tcg_temp_free_i32(ti);
     }