diff options
| -rw-r--r-- | target/arm/translate.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/target/arm/translate.c b/target/arm/translate.c index a5d7723423..7853462b21 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -11594,7 +11594,14 @@ static void disas_thumb_insn(DisasContext *s, uint32_t insn) gen_nop_hint(s, (insn >> 4) & 0xf); break; } - /* If Then. */ + /* + * IT (If-Then) + * + * Combinations of firstcond and mask which set up an 0b1111 + * condition are UNPREDICTABLE; we take the CONSTRAINED + * UNPREDICTABLE choice to treat 0b1111 the same as 0b1110, + * i.e. both meaning "execute always". + */ s->condexec_cond = (insn >> 4) & 0xe; s->condexec_mask = insn & 0x1f; /* No actual code generated for this insn, just setup state. */ @@ -12128,7 +12135,11 @@ static void thumb_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu) if (dc->condexec_mask && !thumb_insn_is_unconditional(dc, insn)) { uint32_t cond = dc->condexec_cond; - if (cond != 0x0e) { /* Skip conditional when condition is AL. */ + /* + * Conditionally skip the insn. Note that both 0xe and 0xf mean + * "always"; 0xf is not "never". + */ + if (cond < 0x0e) { arm_skip_unless(dc, cond); } } |