[PATCH 1/3] target/arm: Make CBZ/CBNZ UNDEF before v6T2

The Thumb CBZ/CBNZ encodings are only introduced in v6T2 (for
A-profile) and v7M (for M-profile).  We missed out the feature-check
in trans_CBZ(), so don't UNDEF on v5T or v6M.  Add the missing check:
conveniently, the ARM_FEATURE_THUMB2 feature is true for exactly the
cases where CBZ is implemented.

Cc: [email protected]
Fixes: 9ee6e8bb853bde ("ARMv7 support.")
Signed-off-by: Peter Maydell <[email protected]>
---
 target/arm/tcg/translate.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/target/arm/tcg/translate.c b/target/arm/tcg/translate.c
index 055f3c5b403..df98dc2e34d 100644
--- a/target/arm/tcg/translate.c
+++ b/target/arm/tcg/translate.c
@@ -5783,7 +5783,14 @@ static bool trans_TBH(DisasContext *s, arg_tbranch *a)
 
 static bool trans_CBZ(DisasContext *s, arg_CBZ *a)
 {
-    TCGv_i32 tmp = load_reg(s, a->rn);
+    TCGv_i32 tmp;
+
+    /* CBZ was introduced in v6T2 and v7M */
+    if (!arm_dc_feature(s, ARM_FEATURE_THUMB2)) {
+        return false;
+    }
+
+    tmp = load_reg(s, a->rn);
 
     arm_gen_condlabel(s);
     tcg_gen_brcondi_i32(a->nz ? TCG_COND_EQ : TCG_COND_NE,
-- 
2.43.0