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Same some space by introducing shorthand byte codes for SSE prefixes

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Properly done, all SSE instructions which has the 66/F2/F3 opcode
multiplex need two prefixes: one to control the use of OSP and one to
control the use of REP.  However, it's a four-way select: np/66/F2/F3;
so introduce shorthand bytecodes for that purpose.
This commit is contained in:
H. Peter Anvin 2008-05-20 09:46:24 -07:00
parent 24860b0f0e
commit fff5a47e65
3 changed files with 53 additions and 4 deletions
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27
assemble.c
View File

@ -91,6 +91,10 @@
* \335 - disassemble a rep (0xF3 byte) prefix as repe not rep.
* \340 - reserve <operand 0> bytes of uninitialized storage.
* Operand 0 had better be a segmentless constant.
* \360 - no SSE prefix (== \364\331)
* \361 - 66 SSE prefix (== \366\331)
* \362 - F2 SSE prefix (== \364\332)
* \363 - F3 SSE prefix (== \364\333)
* \364 - operand-size prefix (0x66) not permitted
* \365 - address-size prefix (0x67) not permitted
* \366 - operand-size prefix (0x66) used as opcode extension
@ -1077,6 +1081,13 @@ static int64_t calcsize(int32_t segment, int64_t offset, int bits,
else
length += ins->oprs[0].offset;
break;
case 0360:
break;
case 0361:
case 0362:
case 0363:
length++;
break;
case 0364:
case 0365:
break;
@ -1732,6 +1743,22 @@ static void gencode(int32_t segment, int64_t offset, int bits,
}
break;
case 0360:
break;
case 0361:
bytes[0] = 0x66;
out(offset, segment, bytes, OUT_RAWDATA, 1, NO_SEG, NO_SEG);
offset += 1;
break;
case 0362:
case 0363:
bytes[0] = c - 0362 + 0xf2;
out(offset, segment, bytes, OUT_RAWDATA, 1, NO_SEG, NO_SEG);
offset += 1;
break;
case 0364:
case 0365:
break;

20
disasm.c
View File

@ -874,6 +874,26 @@ static int matches(const struct itemplate *t, uint8_t *data,
case 0340:
return false;
case 0360:
if (prefix->osp || prefix->rep)
return false;
break;
case 0361:
if (!prefix->osp || prefix->rep)
return false;
break;
case 0362:
if (prefix->osp || prefix->rep != 0xf2)
return false;
break;
case 0363:
if (prefix->osp || prefix->rep != 0xf3)
return false;
break;
case 0364:
if (prefix->osp)
return false;

10
insns.pl
View File

@ -539,13 +539,13 @@ sub byte_code_compile($) {
} elsif ($prefix_ok && $op =~ /^(66|f2|f3|np)$/) {
# 66/F2/F3 prefix used as an opcode extension, or np = no prefix
if ($op eq '66') {
push(@codes, 0366, 0331);
push(@codes, 0361);
} elsif ($op eq 'f2') {
push(@codes, 0332, 0364);
push(@codes, 0362);
} elsif ($op eq 'f3') {
push(@codes, 0333, 0364);
push(@codes, 0363);
} else {
push(@codes, 0331, 0364);
push(@codes, 0360);
}
} elsif ($op =~ /^[0-9a-f]{2}$/) {
if (defined($litix) && $litix+$codes[$litix]+1 == scalar @codes) {
@ -678,6 +678,7 @@ sub byte_code_compile($) {
die "$0: $line: $op without 'i' and 's' operands\n";
}
push(@codes, 0172, ($oppos{'s'} << 3)+$oppos{'i'});
$prefix_ok = 0;
} elsif ($op =~ /^(is4|imz2)\=([0-9]+)$/) {
my $imm = $2;
if (!defined($oppos{'s'})) {
@ -687,6 +688,7 @@ sub byte_code_compile($) {
die "$0: $line: invalid imm4 value for $op: $imm\n";
}
push(@codes, 0173, ($oppos{'s'} << 4) + $imm);
$prefix_ok = 0;
} elsif ($op =~ /^([0-9a-f]{2})\+s$/) {
if (!defined($oppos{'i'})) {
die "$0: $op without 'i' operand\n";