diff options
Diffstat (limited to 'include/opcode/i386.h')
| -rw-r--r-- | include/opcode/i386.h | 10 |
1 files changed, 1 insertions, 9 deletions
diff --git a/include/opcode/i386.h b/include/opcode/i386.h index 2b2c1e0f9..c46c86d4c 100644 --- a/include/opcode/i386.h +++ b/include/opcode/i386.h @@ -179,19 +179,11 @@ static const template i386_optab[] = /* Exchange instructions. xchg commutes: we allow both operand orders. - In the 64bit code, xchg eax, eax is reused for new nop instruction. */ -#if 0 /* While the two entries that are disabled generate shorter code - for xchg eax, reg (on x86_64), the special case xchg eax, eax - does not get handled correctly - it degenerates into nop, but - that way the side effect of zero-extending eax to rax is lost. */ -{"xchg", 2, 0x90, X, 0, wlq_Suf|ShortForm, { WordReg, Acc, 0 } }, -{"xchg", 2, 0x90, X, 0, wlq_Suf|ShortForm, { Acc, WordReg, 0 } }, -#else + In the 64bit code, xchg rax, rax is reused for new nop instruction. */ {"xchg", 2, 0x90, X, CpuNo64, wl_Suf|ShortForm, { WordReg, Acc, 0 } }, {"xchg", 2, 0x90, X, CpuNo64, wl_Suf|ShortForm, { Acc, WordReg, 0 } }, {"xchg", 2, 0x90, X, Cpu64, wq_Suf|ShortForm, { Reg16|Reg64, Acc, 0 } }, {"xchg", 2, 0x90, X, Cpu64, wq_Suf|ShortForm, { Acc, Reg16|Reg64, 0 } }, -#endif {"xchg", 2, 0x86, X, 0, bwlq_Suf|W|Modrm, { Reg, Reg|AnyMem, 0 } }, {"xchg", 2, 0x86, X, 0, bwlq_Suf|W|Modrm, { Reg|AnyMem, Reg, 0 } }, |