76cff100be
The LDRD (register) instruction is UNPREDICTABLE if the Rm register is the same as either Rt or Rt+1 (the two registers being loaded to). We weren't making sure we avoided this, with the result that on some host CPUs like the Cortex-A7 we would get a SIGILL because the CPU chooses to UNDEF for this particular UNPREDICTABLE case. Since we've already checked that datalo is aligned, we can simplify the test vs the Rm operand by aligning it before comparison. Check for the two orderings before falling back to two ldr instructions. We don't bother to do anything similar for tcg_out_ldrd_rwb(), because it is only used in tcg_out_tlb_read() with a fixed set of registers which don't overlap. There is no equivalent UNPREDICTABLE case for STRD. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/896 Signed-off-by: Richard Henderson <richard.henderson@linaro.org> |
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| .. | ||
| tcg-target-con-set.h | ||
| tcg-target-con-str.h | ||
| tcg-target.c.inc | ||
| tcg-target.h | ||
| tcg-target.opc.h | ||