Commit 4a6fd938 authored by Richard Henderson's avatar Richard Henderson
Browse files

target-i386: Tidy prefix parsing 



Avoid duplicating switch statement between 32 and 64-bit modes.

Signed-off-by: default avatarRichard Henderson <rth@twiddle.net>
parent 988c3eb0

target-i386/translate.c

+52 −82
Original line number Diff line number Diff line
@@ -4267,9 +4267,7 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s, 
 next_byte:

    b = cpu_ldub_code(env, s->pc);

    s->pc++;

    /* check prefixes */

#ifdef TARGET_X86_64

    if (CODE64(s)) {

    /* Collect prefixes.  */

    switch (b) {

    case 0xf3:

        prefixes |= PREFIX_REPZ;
@@ -4304,7 +4302,9 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s, 
    case 0x67:

        prefixes |= PREFIX_ADR;

        goto next_byte;

#ifdef TARGET_X86_64

    case 0x40 ... 0x4f:

        if (CODE64(s)) {

            /* REX prefix */

            rex_w = (b >> 3) & 1;

            rex_r = (b & 0x4) << 1;
@@ -4313,58 +4313,28 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s, 
            x86_64_hregs = 1; /* select uniform byte register addressing */

            goto next_byte;

        }

        break;

#endif

    }



    /* Post-process prefixes.  */

    if (prefixes & PREFIX_DATA) {

        dflag ^= 1;

    }

    if (prefixes & PREFIX_ADR) {

        aflag ^= 1;

    }

#ifdef TARGET_X86_64

    if (CODE64(s)) {

        if (rex_w == 1) {

            /* 0x66 is ignored if rex.w is set */

            dflag = 2;

        } else {

            if (prefixes & PREFIX_DATA)

                dflag ^= 1;

        }

        if (!(prefixes & PREFIX_ADR))

        if (!(prefixes & PREFIX_ADR)) {

            aflag = 2;

    } else

#endif

    {

        switch (b) {

        case 0xf3:

            prefixes |= PREFIX_REPZ;

            goto next_byte;

        case 0xf2:

            prefixes |= PREFIX_REPNZ;

            goto next_byte;

        case 0xf0:

            prefixes |= PREFIX_LOCK;

            goto next_byte;

        case 0x2e:

            s->override = R_CS;

            goto next_byte;

        case 0x36:

            s->override = R_SS;

            goto next_byte;

        case 0x3e:

            s->override = R_DS;

            goto next_byte;

        case 0x26:

            s->override = R_ES;

            goto next_byte;

        case 0x64:

            s->override = R_FS;

            goto next_byte;

        case 0x65:

            s->override = R_GS;

            goto next_byte;

        case 0x66:

            prefixes |= PREFIX_DATA;

            goto next_byte;

        case 0x67:

            prefixes |= PREFIX_ADR;

            goto next_byte;

        }

        if (prefixes & PREFIX_DATA)

            dflag ^= 1;

        if (prefixes & PREFIX_ADR)

            aflag ^= 1;

    }

#endif



    s->prefix = prefixes;

    s->aflag = aflag;