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target-i386: Tidy prefix parsing

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

Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2013-01-10 13:29:23 -08:00
parent 988c3eb0d6
commit 4a6fd938f5
1 changed files with 52 additions and 82 deletions
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134
target-i386/translate.c
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@ -4267,44 +4267,44 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s,
next_byte:
b = cpu_ldub_code(env, s->pc);
s->pc++;
/* check prefixes */
/* Collect prefixes. */
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;
#ifdef TARGET_X86_64
if (CODE64(s)) {
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;
case 0x40 ... 0x4f:
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;