diff options
| -rw-r--r-- | target/arm/tcg/translate.c | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/target/arm/tcg/translate.c b/target/arm/tcg/translate.c index 48927fbb8c..b3660173d1 100644 --- a/target/arm/tcg/translate.c +++ b/target/arm/tcg/translate.c @@ -7882,7 +7882,7 @@ static void op_addr_block_post(DisasContext *s, arg_ldst_block *a, } } -static bool op_stm(DisasContext *s, arg_ldst_block *a, int min_n) +static bool op_stm(DisasContext *s, arg_ldst_block *a) { int i, j, n, list, mem_idx; bool user = a->u; @@ -7899,7 +7899,14 @@ static bool op_stm(DisasContext *s, arg_ldst_block *a, int min_n) list = a->list; n = ctpop16(list); - if (n < min_n || a->rn == 15) { + /* + * This is UNPREDICTABLE for n < 1 in all encodings, and we choose + * to UNDEF. In the T32 STM encoding n == 1 is also UNPREDICTABLE, + * but hardware treats it like the A32 version and implements the + * single-register-store, and some in-the-wild (buggy) software + * assumes that, so we don't UNDEF on that case. + */ + if (n < 1 || a->rn == 15) { unallocated_encoding(s); return true; } @@ -7935,8 +7942,7 @@ static bool op_stm(DisasContext *s, arg_ldst_block *a, int min_n) static bool trans_STM(DisasContext *s, arg_ldst_block *a) { - /* BitCount(list) < 1 is UNPREDICTABLE */ - return op_stm(s, a, 1); + return op_stm(s, a); } static bool trans_STM_t32(DisasContext *s, arg_ldst_block *a) @@ -7946,11 +7952,10 @@ static bool trans_STM_t32(DisasContext *s, arg_ldst_block *a) unallocated_encoding(s); return true; } - /* BitCount(list) < 2 is UNPREDICTABLE */ - return op_stm(s, a, 2); + return op_stm(s, a); } -static bool do_ldm(DisasContext *s, arg_ldst_block *a, int min_n) +static bool do_ldm(DisasContext *s, arg_ldst_block *a) { int i, j, n, list, mem_idx; bool loaded_base; @@ -7979,7 +7984,14 @@ static bool do_ldm(DisasContext *s, arg_ldst_block *a, int min_n) list = a->list; n = ctpop16(list); - if (n < min_n || a->rn == 15) { + /* + * This is UNPREDICTABLE for n < 1 in all encodings, and we choose + * to UNDEF. In the T32 LDM encoding n == 1 is also UNPREDICTABLE, + * but hardware treats it like the A32 version and implements the + * single-register-load, and some in-the-wild (buggy) software + * assumes that, so we don't UNDEF on that case. + */ + if (n < 1 || a->rn == 15) { unallocated_encoding(s); return true; } @@ -8045,8 +8057,7 @@ static bool trans_LDM_a32(DisasContext *s, arg_ldst_block *a) unallocated_encoding(s); return true; } - /* BitCount(list) < 1 is UNPREDICTABLE */ - return do_ldm(s, a, 1); + return do_ldm(s, a); } static bool trans_LDM_t32(DisasContext *s, arg_ldst_block *a) @@ -8056,16 +8067,14 @@ static bool trans_LDM_t32(DisasContext *s, arg_ldst_block *a) unallocated_encoding(s); return true; } - /* BitCount(list) < 2 is UNPREDICTABLE */ - return do_ldm(s, a, 2); + return do_ldm(s, a); } static bool trans_LDM_t16(DisasContext *s, arg_ldst_block *a) { /* Writeback is conditional on the base register not being loaded. */ a->w = !(a->list & (1 << a->rn)); - /* BitCount(list) < 1 is UNPREDICTABLE */ - return do_ldm(s, a, 1); + return do_ldm(s, a); } static bool trans_CLRM(DisasContext *s, arg_CLRM *a) |