| Message ID | 1491844419-12485-3-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | arm: Implement M profile exception return properly | expand |
diff --git a/target/arm/translate.c b/target/arm/translate.c index fe3f442..ddc62b6 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -9959,7 +9959,7 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw gen_arm_shift_reg(tmp, op, tmp2, logic_cc); if (logic_cc) gen_logic_CC(tmp); - store_reg_bx(s, rd, tmp); + store_reg(s, rd, tmp); break; case 1: /* Sign/zero extend. */ op = (insn >> 20) & 7;
In Thumb mode, the only instructions which can cause an interworking branch by writing the PC are BLX, BX, BXJ, LDR, POP and LDM. Unlike ARM mode, data processing instructions which target the PC do not cause interworking branches. When we added support for doing interworking branches on writes to PC from data processing instructions in commit 21aeb3430ce7ba, we accidentally changed a Thumb instruction to have interworking branch behaviour for writes to PC. (MOV, MOVS register-shifted register, encoding T2; this is the standard encoding for LSL/LSR/ASR/ROR (register).) For this encoding, behaviour with Rd == R15 is specified as UNPREDICTABLE, so allowing an interworking branch is within spec, but it's confusing and differs from our handling of this class of UNPREDICTABLE for other Thumb ALU operations. Make it perform a simple (non-interworking) branch like the others. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- target/arm/translate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.7.4