[Qemu-devel] [PATCH] target-arm: always use user mode registers as operands for load/store multiple

[Ildar Isaev]

Pseudocode fragment for STM instruction in ARMv8 spec:

if registers<i> == '1' then // Store User mode register
    MemA[address,4] = Rmode[i, M32_User];

Signed-off-by: Ildar Isaev <i...@inbox.ru>
---
 target-arm/translate.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/target-arm/translate.c b/target-arm/translate.c
index 622aa03..ca0ce3f 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -8907,16 +8907,14 @@ static void disas_arm_insn(DisasContext *s, unsigned 
int insn)
                             /* load */
                             tmp = tcg_temp_new_i32();
                             gen_aa32_ld32u(tmp, addr, get_mem_index(s));
-                            if (user) {
+                            if (!user && (i == rn)) {
+                                loaded_var = tmp;
+                                loaded_base = 1;
+                            } else {
                                 tmp2 = tcg_const_i32(i);
                                 gen_helper_set_user_reg(cpu_env, tmp2, tmp);
                                 tcg_temp_free_i32(tmp2);
                                 tcg_temp_free_i32(tmp);
-                            } else if (i == rn) {
-                                loaded_var = tmp;
-                                loaded_base = 1;
-                            } else {
-                                store_reg_from_load(s, i, tmp);
                             }
                         } else {
                             /* store */
@@ -8925,13 +8923,11 @@ static void disas_arm_insn(DisasContext *s, unsigned 
int insn)
                                 val = (long)s->pc + 4;
                                 tmp = tcg_temp_new_i32();
                                 tcg_gen_movi_i32(tmp, val);
-                            } else if (user) {
+                            } else {
                                 tmp = tcg_temp_new_i32();
                                 tmp2 = tcg_const_i32(i);
                                 gen_helper_get_user_reg(tmp, cpu_env, tmp2);
                                 tcg_temp_free_i32(tmp2);
-                            } else {
-                                tmp = load_reg(s, i);
                             }
                             gen_aa32_st32(tmp, addr, get_mem_index(s));
                             tcg_temp_free_i32(tmp);
-- 
1.9.3