[Bug binutils/32462] objdump incorrectly disassembles PAUSE with REX.B prefix

[michaeljclark at mac dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=32462

--- Comment #1 from Michael Clark <michaeljclark at mac dot com> ---
QEMU ignores REP prefix and treats REX.B PAUSE as 'xchg eax, r8d':

    /* If REX_B is set, then this is xchg eax, r8d, not a nop.  */
    if (REX_B(s)) {
        goto do_xchg_reg_eax;
    }
    if (prefixes & PREFIX_REPZ) {
        gen_update_cc_op(s);
        gen_jmp_im(s, pc_start - s->cs_base);
        gen_helper_pause(cpu_env, tcg_const_i32(s->pc - pc_start));
        s->base.is_jmp = DISAS_NORETURN;
    }       

commit 7418027ea4fec276455abd4291558bc58a0a7ba7

    target-i386: fix xchg rax,r8

    We were ignoring REX_B while special-casing NOP, i.e. xchg eax,eax.

-- 
You are receiving this mail because:
You are on the CC list for the bug.