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Fix disassembly of XCHG

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"REX.B 90" in 64-bit mode is "xchg eax,r8d" not "nop"; equivalent
situation for "REX.WB 90" (xchg rax,r8).
This commit is contained in:
H. Peter Anvin 2007-11-12 21:02:33 -08:00
parent f72151f43e
commit 2344010d26
3 changed files with 28 additions and 1 deletions
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15
assemble.c
View file

@ -54,6 +54,10 @@
* \311 - indicates fixed 32-bit address size, i.e. optional 0x67.
* \312 - (disassembler only) marker on LOOP, LOOPxx instructions.
* \313 - indicates fixed 64-bit address size, 0x67 invalid.
* \314 - (disassembler only) invalid with REX.B
* \315 - (disassembler only) invalid with REX.X
* \316 - (disassembler only) invalid with REX.R
* \317 - (disassembler only) invalid with REX.W
* \320 - indicates fixed 16-bit operand size, i.e. optional 0x66.
* \321 - indicates fixed 32-bit operand size, i.e. optional 0x66.
* \322 - indicates that this instruction is only valid when the
@ -965,6 +969,11 @@ static int64_t calcsize(int32_t segment, int64_t offset, int bits,
has_prefix(ins, PPS_ASIZE, P_A32))
return -1;
break;
case 0314:
case 0315:
case 0316:
case 0317:
break;
case 0320:
length += (bits != 16);
break;
@ -1491,6 +1500,12 @@ static void gencode(int32_t segment, int64_t offset, int bits,
ins->rex = 0;
break;
case 0314:
case 0315:
case 0316:
case 0317:
break;
case 0320:
if (bits != 16) {
*bytes = 0x66;

12
disasm.c
View file

@ -584,6 +584,18 @@ static int matches(const struct itemplate *t, uint8_t *data,
return false;
else
a_used = true;
} else if (c == 0314) {
if (prefix->rex & REX_B)
return false;
} else if (c == 0315) {
if (prefix->rex & REX_X)
return false;
} else if (c == 0316) {
if (prefix->rex & REX_R)
return false;
} else if (c == 0317) {
if (prefix->rex & REX_W)
return false;
} else if (c == 0320) {
if (osize != 16)
return false;

2
insns.dat
View file

@ -773,7 +773,7 @@ NEG rm8 \1\xF6\203 8086
NEG rm16 \320\1\xF7\203 8086
NEG rm32 \321\1\xF7\203 386
NEG rm64 \324\1\xF7\203 X64
NOP void \1\x90 8086
NOP void \314\1\x90 8086
NOP rm16 \320\2\x0F\x1F\200 P6
NOP rm32 \321\2\x0F\x1F\200 P6
NOP rm64 \324\2\x0F\x1F\200 X64